doi:10.1111/codi.12919
Original article
Management of tailgut cysts in a tertiary referral centre: a 10-year experience D. Patsouras, N. Pawa, H. Osmani and R. K. S. Phillips Department of Surgery, St Mark’s Hospital and Academic Institute, Harrow, UK Received 31 August 2014; accepted 31 December 2014; Accepted Article online 13 February 2015
Abstract Aim Tailgut cysts are rare congenital lesions typically presenting as presacral masses. A variable clinical presentation often leads to misdiagnosis and unsuccessful operations. Method A retrospective analysis was performed of tailgut cysts presenting to one surgeon at St Mark’s hospital between 2003 and 2013. The patient demographic data and clinicopathological and radiological features, together with perioperative details and recurrence, were reviewed. Results A total of 17 patients (15 women) with a median age of 35 (21–64) years were included in the study. The mean duration of symptoms before referral was 40 months, with sepsis predominating in 12 cases. Fifteen of the patients had previously undergone surgery (mean 2.9 procedures). A posterior surgical approach was adopted in all patients with a coccygectomy performed in 13. A loop colostomy was formed in three patients. Two of them went on to have a secondary
Introduction Tailgut cysts, also known as rectrorectal cystic hamartomas or mucin-secreting cysts, are congenital lesions arising from the remnants of the embryological tailgut [1]. They arise mainly in the presacral space, a potential space defined posteriorly by Waldeyer’s fascia, anteriorly by the fascia propria of the rectum, laterally by the ureters and the lateral ligaments of the rectum, inferiorly by the levator ani and coccygeus muscles and superiorly by the peritoneal reflection between the second and third sacral segments [2,3]. Cases have also been described anterior to the rectum, perianally or even in the perirenal region [4–6]. Tailgut cysts can be the source of chronic perirectal and perianal symptoms and Correspondence to: Prof. Robin K. S Phillips, St Mark’s Hospital and Academic Institute, Watford Road, Harrow HA1 3UJ, UK. E-mail: [email protected]
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pull-through operation after an initial failed local repair of rectal injury. One case was reported to show malignant degeneration on histological examination. There was one recurrence during a median follow-up period of 13 (3–36) months. Conclusion Tailgut cysts are an uncommon yet important cause of chronic perianal sepsis. Suspicion should be raised in a patient, usually female, presenting with a history of unsuccessful procedures. Diagnosis can be made by clinical assessment and MRI. Complete excision usually resolves the problem. Keywords Tailgut cyst, retrorectal cystic hamartoma, retrorectal space, developmental cyst What does this paper add to the literature? Although tailgut cysts are rare congenital lesions, they should be included in the differential diagnosis of recurrent perianal/perineal sepsis and a history of multiple perianal operations.
are therefore often unrecognized, misdiagnosed and undertreated, leading to the patient having multiple operations before the final diagnosis is made. The aim of this study was to report one surgeon’s experience with tailgut cysts over a 10-year period in a tertiary referral centre.
Method A retrospective review was performed of all tailgut cysts presenting to one surgeon (RKSP) at St Mark’s Hospital between 2003 and 2013. Preoperative evaluation was a pelvic MRI in all cases. No preoperative biopsy was performed given the risk of infection or malignant implantation. Patient demographics, the diagnosis at referral, clinical presentation, surgical history, operative details, morbidity, the results of radiology and histopathological examinations and recurrence rates were
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Management of tailgut cysts
recorded. The data were collected from the operative logbooks and the clinical notes of the patients.
Table 1 Clinical presentation of the 17 patients. Clinical presentation
Frequency
Operative technique
Perianal pain Recurrent perianal sepsis Perianal sinus discharge Pelvic pain Constipation Lower abdominal pain Recurrent presacral abscess Recurrent gluteal abscess Back pain Urinary retention Lower limb neurology Asymptomatic
13 12 3 3 1 1 1 1 1 1 1 1
Provided that a review of the sagittal MRI scan suggested the upper border of the cyst could be removed after coccygectomy, a posterior approach was employed. The patient was placed in the prone jack-knife position. A parasacrococcygeal incision was made, extending to the edge of the anal sphincters at 6 o’clock. The coccyx was removed, and the supralevator space entered. Rarely a transanal digital examination was used to confirm the posterior rectal wall, facilitate dissection or prevent injury. Such a manoeuvre can be very helpful, although in order to free both hands of the primary surgeon the finger of the assistant can be used which can lead to a lack of direct feedback and increase the potential risk of septic contamination. The operating surgeon has learnt to recognize submucosal vessels when they are exposed during the dissection and has found this a useful alternative guide. Larger lesions necessitated a coccygectomy or even excision of S5-4. All wounds were closed primarily. A drain was placed in all cases. In the case of larger cysts (< 5–6 cm) or those rising above the sacral promontory, a combined abdominosacral approach was adopted. This technique ensured maximal vascular control together with good exposure. The anterior/abdominal approach commenced with the patient in the modified Lloyd-Davis position. Laparotomy was performed first, followed by posterior dissection and mobilization of the cyst. Mobilization of the rectum from above made resolution of the mass from below a simpler procedure. The abdomen was then closed and the patient placed in the prone jack-knife position. The perineal approach described above was then employed.
On referral the correct diagnosis was made in all patients based on history, physical examination and pelvic MRI (Figs. 1 and 2). Preoperative biopsy was not performed in any case. The surgical procedure was performed only through a posterior approach in 16 patients, with resection of the coccyx in 13 (81%) and a minimal sacrectomy (S5) in one patient. A combined approach (abdominal and posterior) was used for one patient because of the size of the cyst (110 9 90 9 70 mm). The actual decision is based on whether the cyst can reasonably be removed through the opening used with a posterior approach if it is still intact. Those that clearly cannot must either be removed abdominally or in bits and pieces from a posterior approach, which is aesthetically and, rarely, oncologically unattractive. The cysts were often multiple, and some of the bunches of cysts which might be entered during resection with the main cyst remaining intact were small. Most patients had active or past severe sepsis, making the cyst wall adherent to the rec-
Results
Table 2 Previous operations before referral.
Seventeen patients of median age 35 (21–64) years underwent resection of a tailgut cyst by one surgeon between 2003 and 2013 at St Mark’s Hospital. Fifteen of the patients were women. The average duration of symptoms before referral was 40 months, with a range of 6–120 months. Table 1 shows the range of presenting symptoms. Diagnoses made before referral included perianal abscess and fistula-in-ano (10), tailgut cyst (2), recurrence of a previously excised tailgut cyst, gluteal abscess, presacral abscess and mass behind the rectum. Fifteen of the 17 patients had undergone diagnostic or attempted therapeutic surgery before referral, with a mean of 2.9 operations and a range of 0–5 (Table 2).
Type of operation
n
EUA + incision and drainage of perianal abscess EUA + laying open of anal fistula EUA + insertion of seton Debridement of abscess cavity EUA + fistulectomy EUA +advancement flap Laparotomy for pelvic pus drainage Diagnostic laparoscopy Excision of tailgut cyst Excision of pericoccygeal sebaceous cyst
28 3 3 3 1 1 1 1 1 1
EUA, examination under anaesthesia.
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Sepsis encircling the rectum
Tail gut cyst
Figure 1 Tailgut cyst with associated sepsis encircling the rectum.
procedure. Another patient developed severe anal pain and developed purulent and faecal discharge from the wound which was treated by washout of the wound and formation of a loop colostomy. She has since had a pull-through operation. Both cases having a pullthrough had undergone previous surgery before referral to St Mark’s Hospital. The first had an examination under anaesthesia with drainage of perianal sepsis and excision of a pericoccygeal sebaceous cyst and the second had an incision and drainage of perianal sepsis and laying open of anal fistula. The median follow-up was 13 months (3–36) with one recurrence to date.
Discussion Sepsis in rectovaginal septum
Tail gut cyst
Figure 2 Tailgut cyst with associated sepsis in the rectovaginal septum.
tum; in some the abscess had been drained directly into the rectum. In such cases the cysts were already ruptured and communicating with the septic process. Three patients required stoma formation (loop colostomy) because of preexisting or intra-operative injury of the rectum. Removal of the dominant cyst was achieved in all patients. Blood losses were insignificant in all cases (< 200 ml). Cysts size varied between patients. The smallest was 35 9 35 9 30 mm and the largest was 110 9 90 9 70 mm based on histological assessment/ MRI. Histological examination of the specimens showed 16 patients to have benign tailgut cysts; there was one patient with malignant degeneration (carcinoid) in the cyst. In all patients the cysts had a variable lining, either by columnar epithelium, cuboidal epithelium, squamous epithelium or transitional type epithelium. The median inpatient hospital stay was 7 (3–14) days. There was no postoperative mortality. Three patients developed a wound infection which was treated with antibiotics. One of patients who had previously had a posterior approach with a defunctioning loop colostomy because of intra-operative injury of the rectum subsequently developed a breakdown of the rectal repair and later underwent a colo-anal pull-through
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Lesions occurring in the presacral space include primary tumours of neurogenic, osteogenic and congenital origin and inflammatory or metastatic masses. Miscellaneous lesions such as liposarcoma, lipoma, desmoid tumour, fibroma or leiomyoma also originate in this space. Congenital lesions such as chordoma, teratoma, anterior meningocoele and developmental cysts (dermoid, epidemoid, duplication and tailgut cysts) generate more than half of all presacral tumours, accounting for a majority of the retrorectal cystic lesions seen in adults [7,8]. Developmental cysts are the most common entity encountered in the retrorectal/presacral space, and include epidermoid cysts, dermoid cysts and enteric cysts [9,10]. There are two types of enteric cysts: tailgut cysts (also called retrorectal cyst-hamartomas or mucinsecreting cysts) and cystic rectal duplication. Duplication cysts are unilocular and lined by epithelium similar to that within the gastrointestinal or respiratory tracts with villi and crypts. They contain a well-formed muscular layer of two layers of bundles with nerve plexuses. In comparison tailgut cysts are multiloculated and lined by a variety of different epithelia, even within the same cyst, with focal disorganized muscle bundles [11]. Middledorpf described the first congenital retrorectal cyst in 1885 in a 1-year-old girl, and the clarification between the two forms of enteric cysts was made some years later by Peyron in 1928 [12]. Tailgut cysts are thought to arise from remnants of the embryological hindgut. At approximately 28–35 days of gestation, the human embryo has a true tail, which regresses over the next 20 days. The primitive hindgut extends into this tail, caudal to the subsequent formation of the anus, hence the name tailgut. Normally by the eighth embryonic week such a tailgut atrophies and involutes; however, in some cases it fails to regress completely, with the remnants giving rise to tailgut cysts [11].
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It is difficult to estimate the true incidence of tailgut cysts because of the lack of large series, with the literature containing mostly single case reports and small case series. Presacral tumours including tailgut cysts were responsible for an estimated 1/40 000 hospital admissions to the Mayo Clinic between 1960 and 1979 [9]. They can occur at any age, but are predominantly seen in the fifth decade. There is a strong female predominance, with gender ratios ranging from 3:1 to 9:1. The female:male ratio in the present study was 7:1 [7,13,14]. The clinical presentation of tailgut cysts is usually nonspecific and misleading. Half of the patients are asymptomatic and the cysts are found incidentally. Patients present with constipation, diarrhoea, rectal pain or bleeding, change in stool calibre, obstructed defaecation, tenesmus, abdominal pain, back pain, symptoms associated with urinary obstruction and lower limb neurology by compression of the sacral plexus. Infection can be the presenting symptom in some patients. In our study, 12 of the 17 patients were referred to St Marks because of perianal, gluteal or presacral abscess formation and fistula-in-ano. The appearance of a draining sinus or fistula tract or a perianal, gluteal or pilonidal abscess can often lead to misdiagnosis of fistula-in-ano. Recurrent perianal/perineal sepsis can be very difficult to manage. A tailgut cyst is a rare cause of recurrent sepsis but should be considered in the appropriate setting. A history of multiple perianal operations, recurring abscesses and an inability to locate the source of infection in the presence of a persistent perianal sinus should be a warning to the surgeon to consider a tailgut cyst in the differential diagnosis. Magnetic resonance imaging (MRI) improves tissue characterization because of its high-contrast resolution between different tissue compartments. It is wise in each case to use imaging to identify the correct tumour location and size, together with morphology and interface, and identify invasion of other structures or the sacrum [15]. On MRI, tailgut cysts have been reported to demonstrate either unilocular or multilocular cystic appearances. Usually they have low signal intensity on T1-weighted images and high signal intensity on T2-weighted images [16–18]. However, a high signal intensity can also be seen on T1-weighted images due to the presence of mucinous material, a high protein content or even haemorrhage into the cyst [17,19]. Another feature seen on MRI is the frequent presence of small cysts clustered together and adjacent to the main cyst, thus resulting in a honeycomb pattern [20]. Malignant degeneration or fibrous tissue within the cysts can be identified as irregular wall thickening with intermediate signal intensity on
Management of tailgut cysts
both T1- and T2-weighted images with intravenous contrast [19]. On CT scans a well-marginated, presacral mass with water or soft-tissue density is seen, depending on the contents, with calcifications also seen. In cases of concurrent infection or malignant degeneration CT scanning may reveal loss of discrete margins together with involvement of neighbouring structures [16,21,22]. In the Mayo Clinic study from 1985 to 2008, Mathis et al. [14] utilized CT scanning preoperatively in all cases to guide surgical planning, confirming the size, upper extent of the cyst, presence of inflammation/ infection, adherence to neighbouring structures and the presence of malignant features. MRI scanning, however, is regarded to offer clearer visualization of the multilocular appearance of the tailgut cyst together with improved detection of smaller peripheral cysts. Sagittal MRI images offer an optimal view of the relation of the mass lesions to surrounding bony structures and the rectum. By offering multiplanar capabilities and good tissue contrast, MRI images are superior for the surgical planning of presacral masses [17,23]. The diagnosis in this series was made preoperatively in all cases based on the MRI scans and clinical presentation, and then confirmed histologically on excision. In most cases the diagnosis had not been made by the referring clinical team. Given the particular experience of the senior surgeon with anorectal sepsis, the case series is skewed towards these cases rather than those with a potential or actual malignant component. Lesions presenting with a potential solid component on MRI scans represent a difficult problem as a radiologically guided biopsy can lead to haemorrhage into the cyst and subsequent secondary infection. Those with clearly invasive features can and should be biopsied, but for those where a complete surgical excision seems likely to be possible, immediate resection as a ‘big biopsy’ without prior radiological biopsy would seem sensible. Malignant degeneration in a tailgut cyst has been described in isolated reports and includes adenocarcinoma, carcinoid and sarcoma [13,16,19,24,25]. In the largest series in the literature from the Armed Services Institute of Pathology in 1988, the rate of malignant transformation was 2%. In comparison, other small-scale studies have reported a malignant degeneration rate ranging from 13% to 40%, with a recent comprehensive literature review of patients ranging from 1932 to 2011 reporting a rate of 14% (47/332). The rate of malignant degeneration identified in our study was 6% [7,13,14,23]. Tailgut cysts are lined with a variety of epithelia, even within the same cyst and they can be filled with mucus. Epithelial types include squamous, transitional,
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Table 3 Summary of findings in case series of tailgut cysts. Author
Year range
No. of TGC
Asymptomatic
Septic
Present study (2014) Chereau et al [28] Macafe et al [15] Mathis et al [14] Aflalo-Hazan et al [20] Grandjean et al [26] Buchs et al [29] Yang et al [23] Lev-Chelouche et al [3] Singer et al [30] Hjermstad and Helwing et al [13] Jao et al [9] Uhlig and Johnson [10]
2003–13 1997–2011 2002–10 1985–2008 2001–07 1989–2005 1994–2003 1995–2003 1991–2001 NA NA 1960–79 30-year period
17 28 13 31 11 16 10 5 12 4 53 16 16
6% (n = 1) NA NA 45% (n = 14) 18% (n = 2) N/A 30% (n = 3) 20% (n = 1) 25% (n = 3) 0% 50% NA NA
76% NA NA NA 27% 12% 10% NA 17% 75% NA NA NA
(n = 12)
(n = 3) (n = 2) (n = 1) (n = 2) (n = 3)
Malignant 6% (n = 1) 21% (n = 6) NA 13% (n = 4) 9% (n = 1) 0% 0% 0% 0% 0% 2% (n = 4) NA NA
TGC, tailgut cyst; NA, not applicable.
mucinous or ciliated columnar and cuboidal epithelium. Smooth muscle fibres are usually seen in association with the cyst but there is an absence of any well-defined muscle wall or myenteric plexus. They were first described in 1928 by Peyron, who concluded that a cystic tumour of tailgut origin must have an intestinal type epithelium and lack of definite muscular or serosal coating [12]. In our study, all the cysts contained columnar epithelium (ciliated or mucinous), 94% also contained squamous epithelium, 53% transitional type epithelium and 12% cuboidal epithelium. The choice of surgical approach is dependent on three specific factors including the degree of proximal extension, whether there is evidence of infection and if the cyst is adherent to neighbouring structures (bladder, ureters, rectum), and whether there is evidence of malignancy necessitating an en bloc organ resection. If above the body of S3 a combined anterior–posterior or anterior alone approach is recommended, The most common is the posterior approach (Kraske). In our experience it has been usual to carry out a coccygectomy, which is advocated by many authors as the coccyx may harbour a nidus of totipotential cells which may lead to recurrence. It is difficult to estimate the recurrence rate after excision of tailgut cysts because of the lack of large series. Recurrence rates of between 0 and 16% have been reported in the case series and literature reviews with follow-up ranging up to 54 months [3,7,13,14,26,27]. In our study there was one patient with a recurrent tailgut cyst after excision. The senior author has a large practice of referral of complex septic problems in the perineum. This would have biased the patient group to have a high incidence of sepsis. As the denominator of asymptomatic cysts in
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the general population is not known, it is impossible to estimate an accurate risk for future sepsis or malignancy. The risk exists, but surgery also has risks, including inadvertent rectal injury, especially in sepsis when an infected cyst may be very adherent to the rectum (Figs. 1 and 2). A comparison of our results with the larger case series in the literature is given in Table 3. Tailgut cysts are a rare source of chronic perianal and perirectal symptoms, and should be included in the differential diagnosis of patients presenting with recurrent sepsis. Diagnosis can often be made with the assistance of MRI imaging and preoperative biopsy is not generally recommended.
Author contributions Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work: DP, NP, HO. Drafting the work or revising it critically for important intellectual content: DP, NP, RP. Final approval of the version to be published: DP, NP, HO, RP. Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved: RP.
References 1 Vega MD, Quintans RA, Hernandez GP et al. [Tailgut cysts]. Cir Esp 2008; 83: 53–60. 2 Wolpert A, Beer-Gabel M, Lifschitz O, Zbar AP. The management of presacral masses in the adult. Tech Coloproctol 2002; 6: 43–9.
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3 Lev-Chelouche D, Gutman M, Goldman G et al. Presacral tumors: a practical classification and treatment of a unique and heterogeneous group of diseases. Surgery 2003; 133: 473–8. 4 Gips M, Melki Y, Wolloch Y. Cysts of the tailgut. Two cases. Eur J Surg 1994; 160: 459–60. 5 Sidoni A, Bucciarelli E. Ciliated cyst of the perineal skin. Am J Dermatopathol 1997; 19: 93–6. 6 Sung MT, Ko SF, Niu CK, Hsieh CS, Huang HY. Perirenal tailgut cyst (cystic hamartoma). J Pediatr Surg 2003; 38: 1404–6. 7 Killingsworth C, Gadacz TR. Tailgut cyst (retrorectal cystic hamartoma): report of a case and review of the literature. Am Surg 2005; 71: 666–73. 8 Leborgne J, Guiberteau B, Lehur PA, Le Goff M, Le Neel JC, Nomballais MF. [Retro-rectal cystic tumors of developmental origin in adults. Apropos of 2 cases]. Chirurgie 1989; 115: 565–71. 9 Jao SW, Beart RW Jr, Spencer RJ Reiman HM Ilstrup DM. Retrorectal tumors. Mayo Clinic experience, 1960–1979. Dis Colon Rectum 1985; 28: 644–52. 10 Uhlig BE, Johnson RL. Presacral tumors and cysts in adults. Dis Colon Rectum 1975; 18: 581–9. 11 Prasad AR, Amin MB, Randolph TL, Lee CS, Ma CK. Retrorectal cystic hamartoma: report of 5 cases with malignancy arising in 2. Arch Pathol Lab Med 2000; 124: 725–9. 12 Peyron A. Les vestiges embryonnaires de la region sacrococcygienne et leur role dans la production des kystes ou tumeurs d’origine congenitale. Bull Assoc Fr Etud Cancer 1928; 17: 613–32. 13 Hjermstad BM, Helwig EB. Tailgut cysts. Report of 53 cases. Am J Clin Pathol 1988; 89: 139–47. 14 Mathis KL, Dozois EJ, Grewal MS, Metzger P, Larson DW, Devine RM. Malignant risk and surgical outcomes of presacral tailgut cysts. Br J Surg 2010; 97: 575–9. 15 Macafee DA, Sagar PM, El-Khoury T, Hyland R. Retrorectal tumours: optimization of surgical approach and outcome. Colorectal Dis 2012; 14: 1411–7. 16 Liessi G, Cesari S, Pavanello M, Butini R. Tailgut cysts: CT and MR findings. Abdom Imaging 1995; 20: 256–8.
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17 Kim MJ, Kim WH, Kim NK et al. Tailgut cyst: multilocular cystic appearance on MRI. J Comput Assist Tomogr 1997; 21: 731–2. 18 Lim KE, Hsu WC, Wang CR. Tailgut cyst with malignancy: MR imaging findings. AJR Am J Roentgenol 1998; 170: 1488–90. 19 Moulopoulos LA, Karvouni E, Kehagias D, Dimopoulos MA, Gouliamos A, Vlahos L. MR imaging of complex tailgut cysts. Clin Radiol 1999; 54: 118–22. 20 Aflalo-Hazan V, Rousset P, Mourra N, Lewin M, Azizi L, Hoeffel C. Tailgut cysts: MRI findings. Eur Radiol 2008; 18: 2586–93. 21 Johnson AR, Ros PR, Hjermstad BM. Tailgut cyst: diagnosis with CT and sonography. AJR Am J Roentgenol 1986; 147: 1309–11. 22 Ottery FD, Carlson RA, Gould H, Weese JL. Retrorectal cyst-hamartomas: CT diagnosis. J Comput Assist Tomogr 1986; 10: 260–3. 23 Yang DM, Park CH, Jin W et al. Tailgut cyst: MRI evaluation. AJR Am J Roentgenol 2005; 184: Macafe1519–23. 24 Marco V, Autonell J, Farre J, Fernandez-Layos M, Doncel F. Retrorectal cyst-hamartomas. Report of two cases with adenocarcinoma developing in one. Am J Surg Pathol 1982; 6: 707–14. 25 Tampi C, Lotwala V, Lakdawala M, Coelho K. Retrorectal cyst hamartoma (tailgut cyst) with malignant transformation. Gynecol Oncol 2007; 105: 266–8. 26 Grandjean JP, Mantion GA, Guinier D et al. Vestigial retrorectal cystic tumors in adults: a review of 30 cases. Gastroenterol Clin Biol 2008; 32: 769–78. 27 Woodfield JC, Chalmers AG, Phillips N, Sagar PM. Algorithms for the surgical management of retrorectal tumours. Br J Surg 2008; 95: 214–21. 28 Chereau N, Lefevre JH, Meurette G et al. Surgical resection of retrorectal tumours in adults: long-term results in 47 patients. Colorectal Dis 2013; 15: e476–82. 29 Buchs N, Taylor S, Roche B. The posterior approach for low retrorectal tumors in adults. Int J Colorectal Dis 2007; 22: 381–5. 30 Singer MA, Cintron JR, Martz JE, Schoetz DJ, Abcarian H. Retrorectal cyst: a rare tumor frequently misdiagnosed. J Am Coll Surg 2003; 196: 880–6.
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Original article
Management of tailgut cysts in a tertiary referral centre: a 10-year experience D. Patsouras, N. Pawa, H. Osmani and R. K. S. Phillips Department of Surgery, St Mark’s Hospital and Academic Institute, Harrow, UK Received 31 August 2014; accepted 31 December 2014; Accepted Article online 13 February 2015
Abstract Aim Tailgut cysts are rare congenital lesions typically presenting as presacral masses. A variable clinical presentation often leads to misdiagnosis and unsuccessful operations. Method A retrospective analysis was performed of tailgut cysts presenting to one surgeon at St Mark’s hospital between 2003 and 2013. The patient demographic data and clinicopathological and radiological features, together with perioperative details and recurrence, were reviewed. Results A total of 17 patients (15 women) with a median age of 35 (21–64) years were included in the study. The mean duration of symptoms before referral was 40 months, with sepsis predominating in 12 cases. Fifteen of the patients had previously undergone surgery (mean 2.9 procedures). A posterior surgical approach was adopted in all patients with a coccygectomy performed in 13. A loop colostomy was formed in three patients. Two of them went on to have a secondary
Introduction Tailgut cysts, also known as rectrorectal cystic hamartomas or mucin-secreting cysts, are congenital lesions arising from the remnants of the embryological tailgut [1]. They arise mainly in the presacral space, a potential space defined posteriorly by Waldeyer’s fascia, anteriorly by the fascia propria of the rectum, laterally by the ureters and the lateral ligaments of the rectum, inferiorly by the levator ani and coccygeus muscles and superiorly by the peritoneal reflection between the second and third sacral segments [2,3]. Cases have also been described anterior to the rectum, perianally or even in the perirenal region [4–6]. Tailgut cysts can be the source of chronic perirectal and perianal symptoms and Correspondence to: Prof. Robin K. S Phillips, St Mark’s Hospital and Academic Institute, Watford Road, Harrow HA1 3UJ, UK. E-mail: [email protected]
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pull-through operation after an initial failed local repair of rectal injury. One case was reported to show malignant degeneration on histological examination. There was one recurrence during a median follow-up period of 13 (3–36) months. Conclusion Tailgut cysts are an uncommon yet important cause of chronic perianal sepsis. Suspicion should be raised in a patient, usually female, presenting with a history of unsuccessful procedures. Diagnosis can be made by clinical assessment and MRI. Complete excision usually resolves the problem. Keywords Tailgut cyst, retrorectal cystic hamartoma, retrorectal space, developmental cyst What does this paper add to the literature? Although tailgut cysts are rare congenital lesions, they should be included in the differential diagnosis of recurrent perianal/perineal sepsis and a history of multiple perianal operations.
are therefore often unrecognized, misdiagnosed and undertreated, leading to the patient having multiple operations before the final diagnosis is made. The aim of this study was to report one surgeon’s experience with tailgut cysts over a 10-year period in a tertiary referral centre.
Method A retrospective review was performed of all tailgut cysts presenting to one surgeon (RKSP) at St Mark’s Hospital between 2003 and 2013. Preoperative evaluation was a pelvic MRI in all cases. No preoperative biopsy was performed given the risk of infection or malignant implantation. Patient demographics, the diagnosis at referral, clinical presentation, surgical history, operative details, morbidity, the results of radiology and histopathological examinations and recurrence rates were
Colorectal Disease ª 2015 The Association of Coloproctology of Great Britain and Ireland. 17, 724–729
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Management of tailgut cysts
recorded. The data were collected from the operative logbooks and the clinical notes of the patients.
Table 1 Clinical presentation of the 17 patients. Clinical presentation
Frequency
Operative technique
Perianal pain Recurrent perianal sepsis Perianal sinus discharge Pelvic pain Constipation Lower abdominal pain Recurrent presacral abscess Recurrent gluteal abscess Back pain Urinary retention Lower limb neurology Asymptomatic
13 12 3 3 1 1 1 1 1 1 1 1
Provided that a review of the sagittal MRI scan suggested the upper border of the cyst could be removed after coccygectomy, a posterior approach was employed. The patient was placed in the prone jack-knife position. A parasacrococcygeal incision was made, extending to the edge of the anal sphincters at 6 o’clock. The coccyx was removed, and the supralevator space entered. Rarely a transanal digital examination was used to confirm the posterior rectal wall, facilitate dissection or prevent injury. Such a manoeuvre can be very helpful, although in order to free both hands of the primary surgeon the finger of the assistant can be used which can lead to a lack of direct feedback and increase the potential risk of septic contamination. The operating surgeon has learnt to recognize submucosal vessels when they are exposed during the dissection and has found this a useful alternative guide. Larger lesions necessitated a coccygectomy or even excision of S5-4. All wounds were closed primarily. A drain was placed in all cases. In the case of larger cysts (< 5–6 cm) or those rising above the sacral promontory, a combined abdominosacral approach was adopted. This technique ensured maximal vascular control together with good exposure. The anterior/abdominal approach commenced with the patient in the modified Lloyd-Davis position. Laparotomy was performed first, followed by posterior dissection and mobilization of the cyst. Mobilization of the rectum from above made resolution of the mass from below a simpler procedure. The abdomen was then closed and the patient placed in the prone jack-knife position. The perineal approach described above was then employed.
On referral the correct diagnosis was made in all patients based on history, physical examination and pelvic MRI (Figs. 1 and 2). Preoperative biopsy was not performed in any case. The surgical procedure was performed only through a posterior approach in 16 patients, with resection of the coccyx in 13 (81%) and a minimal sacrectomy (S5) in one patient. A combined approach (abdominal and posterior) was used for one patient because of the size of the cyst (110 9 90 9 70 mm). The actual decision is based on whether the cyst can reasonably be removed through the opening used with a posterior approach if it is still intact. Those that clearly cannot must either be removed abdominally or in bits and pieces from a posterior approach, which is aesthetically and, rarely, oncologically unattractive. The cysts were often multiple, and some of the bunches of cysts which might be entered during resection with the main cyst remaining intact were small. Most patients had active or past severe sepsis, making the cyst wall adherent to the rec-
Results
Table 2 Previous operations before referral.
Seventeen patients of median age 35 (21–64) years underwent resection of a tailgut cyst by one surgeon between 2003 and 2013 at St Mark’s Hospital. Fifteen of the patients were women. The average duration of symptoms before referral was 40 months, with a range of 6–120 months. Table 1 shows the range of presenting symptoms. Diagnoses made before referral included perianal abscess and fistula-in-ano (10), tailgut cyst (2), recurrence of a previously excised tailgut cyst, gluteal abscess, presacral abscess and mass behind the rectum. Fifteen of the 17 patients had undergone diagnostic or attempted therapeutic surgery before referral, with a mean of 2.9 operations and a range of 0–5 (Table 2).
Type of operation
n
EUA + incision and drainage of perianal abscess EUA + laying open of anal fistula EUA + insertion of seton Debridement of abscess cavity EUA + fistulectomy EUA +advancement flap Laparotomy for pelvic pus drainage Diagnostic laparoscopy Excision of tailgut cyst Excision of pericoccygeal sebaceous cyst
28 3 3 3 1 1 1 1 1 1
EUA, examination under anaesthesia.
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Sepsis encircling the rectum
Tail gut cyst
Figure 1 Tailgut cyst with associated sepsis encircling the rectum.
procedure. Another patient developed severe anal pain and developed purulent and faecal discharge from the wound which was treated by washout of the wound and formation of a loop colostomy. She has since had a pull-through operation. Both cases having a pullthrough had undergone previous surgery before referral to St Mark’s Hospital. The first had an examination under anaesthesia with drainage of perianal sepsis and excision of a pericoccygeal sebaceous cyst and the second had an incision and drainage of perianal sepsis and laying open of anal fistula. The median follow-up was 13 months (3–36) with one recurrence to date.
Discussion Sepsis in rectovaginal septum
Tail gut cyst
Figure 2 Tailgut cyst with associated sepsis in the rectovaginal septum.
tum; in some the abscess had been drained directly into the rectum. In such cases the cysts were already ruptured and communicating with the septic process. Three patients required stoma formation (loop colostomy) because of preexisting or intra-operative injury of the rectum. Removal of the dominant cyst was achieved in all patients. Blood losses were insignificant in all cases (< 200 ml). Cysts size varied between patients. The smallest was 35 9 35 9 30 mm and the largest was 110 9 90 9 70 mm based on histological assessment/ MRI. Histological examination of the specimens showed 16 patients to have benign tailgut cysts; there was one patient with malignant degeneration (carcinoid) in the cyst. In all patients the cysts had a variable lining, either by columnar epithelium, cuboidal epithelium, squamous epithelium or transitional type epithelium. The median inpatient hospital stay was 7 (3–14) days. There was no postoperative mortality. Three patients developed a wound infection which was treated with antibiotics. One of patients who had previously had a posterior approach with a defunctioning loop colostomy because of intra-operative injury of the rectum subsequently developed a breakdown of the rectal repair and later underwent a colo-anal pull-through
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Lesions occurring in the presacral space include primary tumours of neurogenic, osteogenic and congenital origin and inflammatory or metastatic masses. Miscellaneous lesions such as liposarcoma, lipoma, desmoid tumour, fibroma or leiomyoma also originate in this space. Congenital lesions such as chordoma, teratoma, anterior meningocoele and developmental cysts (dermoid, epidemoid, duplication and tailgut cysts) generate more than half of all presacral tumours, accounting for a majority of the retrorectal cystic lesions seen in adults [7,8]. Developmental cysts are the most common entity encountered in the retrorectal/presacral space, and include epidermoid cysts, dermoid cysts and enteric cysts [9,10]. There are two types of enteric cysts: tailgut cysts (also called retrorectal cyst-hamartomas or mucinsecreting cysts) and cystic rectal duplication. Duplication cysts are unilocular and lined by epithelium similar to that within the gastrointestinal or respiratory tracts with villi and crypts. They contain a well-formed muscular layer of two layers of bundles with nerve plexuses. In comparison tailgut cysts are multiloculated and lined by a variety of different epithelia, even within the same cyst, with focal disorganized muscle bundles [11]. Middledorpf described the first congenital retrorectal cyst in 1885 in a 1-year-old girl, and the clarification between the two forms of enteric cysts was made some years later by Peyron in 1928 [12]. Tailgut cysts are thought to arise from remnants of the embryological hindgut. At approximately 28–35 days of gestation, the human embryo has a true tail, which regresses over the next 20 days. The primitive hindgut extends into this tail, caudal to the subsequent formation of the anus, hence the name tailgut. Normally by the eighth embryonic week such a tailgut atrophies and involutes; however, in some cases it fails to regress completely, with the remnants giving rise to tailgut cysts [11].
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It is difficult to estimate the true incidence of tailgut cysts because of the lack of large series, with the literature containing mostly single case reports and small case series. Presacral tumours including tailgut cysts were responsible for an estimated 1/40 000 hospital admissions to the Mayo Clinic between 1960 and 1979 [9]. They can occur at any age, but are predominantly seen in the fifth decade. There is a strong female predominance, with gender ratios ranging from 3:1 to 9:1. The female:male ratio in the present study was 7:1 [7,13,14]. The clinical presentation of tailgut cysts is usually nonspecific and misleading. Half of the patients are asymptomatic and the cysts are found incidentally. Patients present with constipation, diarrhoea, rectal pain or bleeding, change in stool calibre, obstructed defaecation, tenesmus, abdominal pain, back pain, symptoms associated with urinary obstruction and lower limb neurology by compression of the sacral plexus. Infection can be the presenting symptom in some patients. In our study, 12 of the 17 patients were referred to St Marks because of perianal, gluteal or presacral abscess formation and fistula-in-ano. The appearance of a draining sinus or fistula tract or a perianal, gluteal or pilonidal abscess can often lead to misdiagnosis of fistula-in-ano. Recurrent perianal/perineal sepsis can be very difficult to manage. A tailgut cyst is a rare cause of recurrent sepsis but should be considered in the appropriate setting. A history of multiple perianal operations, recurring abscesses and an inability to locate the source of infection in the presence of a persistent perianal sinus should be a warning to the surgeon to consider a tailgut cyst in the differential diagnosis. Magnetic resonance imaging (MRI) improves tissue characterization because of its high-contrast resolution between different tissue compartments. It is wise in each case to use imaging to identify the correct tumour location and size, together with morphology and interface, and identify invasion of other structures or the sacrum [15]. On MRI, tailgut cysts have been reported to demonstrate either unilocular or multilocular cystic appearances. Usually they have low signal intensity on T1-weighted images and high signal intensity on T2-weighted images [16–18]. However, a high signal intensity can also be seen on T1-weighted images due to the presence of mucinous material, a high protein content or even haemorrhage into the cyst [17,19]. Another feature seen on MRI is the frequent presence of small cysts clustered together and adjacent to the main cyst, thus resulting in a honeycomb pattern [20]. Malignant degeneration or fibrous tissue within the cysts can be identified as irregular wall thickening with intermediate signal intensity on
Management of tailgut cysts
both T1- and T2-weighted images with intravenous contrast [19]. On CT scans a well-marginated, presacral mass with water or soft-tissue density is seen, depending on the contents, with calcifications also seen. In cases of concurrent infection or malignant degeneration CT scanning may reveal loss of discrete margins together with involvement of neighbouring structures [16,21,22]. In the Mayo Clinic study from 1985 to 2008, Mathis et al. [14] utilized CT scanning preoperatively in all cases to guide surgical planning, confirming the size, upper extent of the cyst, presence of inflammation/ infection, adherence to neighbouring structures and the presence of malignant features. MRI scanning, however, is regarded to offer clearer visualization of the multilocular appearance of the tailgut cyst together with improved detection of smaller peripheral cysts. Sagittal MRI images offer an optimal view of the relation of the mass lesions to surrounding bony structures and the rectum. By offering multiplanar capabilities and good tissue contrast, MRI images are superior for the surgical planning of presacral masses [17,23]. The diagnosis in this series was made preoperatively in all cases based on the MRI scans and clinical presentation, and then confirmed histologically on excision. In most cases the diagnosis had not been made by the referring clinical team. Given the particular experience of the senior surgeon with anorectal sepsis, the case series is skewed towards these cases rather than those with a potential or actual malignant component. Lesions presenting with a potential solid component on MRI scans represent a difficult problem as a radiologically guided biopsy can lead to haemorrhage into the cyst and subsequent secondary infection. Those with clearly invasive features can and should be biopsied, but for those where a complete surgical excision seems likely to be possible, immediate resection as a ‘big biopsy’ without prior radiological biopsy would seem sensible. Malignant degeneration in a tailgut cyst has been described in isolated reports and includes adenocarcinoma, carcinoid and sarcoma [13,16,19,24,25]. In the largest series in the literature from the Armed Services Institute of Pathology in 1988, the rate of malignant transformation was 2%. In comparison, other small-scale studies have reported a malignant degeneration rate ranging from 13% to 40%, with a recent comprehensive literature review of patients ranging from 1932 to 2011 reporting a rate of 14% (47/332). The rate of malignant degeneration identified in our study was 6% [7,13,14,23]. Tailgut cysts are lined with a variety of epithelia, even within the same cyst and they can be filled with mucus. Epithelial types include squamous, transitional,
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Table 3 Summary of findings in case series of tailgut cysts. Author
Year range
No. of TGC
Asymptomatic
Septic
Present study (2014) Chereau et al [28] Macafe et al [15] Mathis et al [14] Aflalo-Hazan et al [20] Grandjean et al [26] Buchs et al [29] Yang et al [23] Lev-Chelouche et al [3] Singer et al [30] Hjermstad and Helwing et al [13] Jao et al [9] Uhlig and Johnson [10]
2003–13 1997–2011 2002–10 1985–2008 2001–07 1989–2005 1994–2003 1995–2003 1991–2001 NA NA 1960–79 30-year period
17 28 13 31 11 16 10 5 12 4 53 16 16
6% (n = 1) NA NA 45% (n = 14) 18% (n = 2) N/A 30% (n = 3) 20% (n = 1) 25% (n = 3) 0% 50% NA NA
76% NA NA NA 27% 12% 10% NA 17% 75% NA NA NA
(n = 12)
(n = 3) (n = 2) (n = 1) (n = 2) (n = 3)
Malignant 6% (n = 1) 21% (n = 6) NA 13% (n = 4) 9% (n = 1) 0% 0% 0% 0% 0% 2% (n = 4) NA NA
TGC, tailgut cyst; NA, not applicable.
mucinous or ciliated columnar and cuboidal epithelium. Smooth muscle fibres are usually seen in association with the cyst but there is an absence of any well-defined muscle wall or myenteric plexus. They were first described in 1928 by Peyron, who concluded that a cystic tumour of tailgut origin must have an intestinal type epithelium and lack of definite muscular or serosal coating [12]. In our study, all the cysts contained columnar epithelium (ciliated or mucinous), 94% also contained squamous epithelium, 53% transitional type epithelium and 12% cuboidal epithelium. The choice of surgical approach is dependent on three specific factors including the degree of proximal extension, whether there is evidence of infection and if the cyst is adherent to neighbouring structures (bladder, ureters, rectum), and whether there is evidence of malignancy necessitating an en bloc organ resection. If above the body of S3 a combined anterior–posterior or anterior alone approach is recommended, The most common is the posterior approach (Kraske). In our experience it has been usual to carry out a coccygectomy, which is advocated by many authors as the coccyx may harbour a nidus of totipotential cells which may lead to recurrence. It is difficult to estimate the recurrence rate after excision of tailgut cysts because of the lack of large series. Recurrence rates of between 0 and 16% have been reported in the case series and literature reviews with follow-up ranging up to 54 months [3,7,13,14,26,27]. In our study there was one patient with a recurrent tailgut cyst after excision. The senior author has a large practice of referral of complex septic problems in the perineum. This would have biased the patient group to have a high incidence of sepsis. As the denominator of asymptomatic cysts in
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the general population is not known, it is impossible to estimate an accurate risk for future sepsis or malignancy. The risk exists, but surgery also has risks, including inadvertent rectal injury, especially in sepsis when an infected cyst may be very adherent to the rectum (Figs. 1 and 2). A comparison of our results with the larger case series in the literature is given in Table 3. Tailgut cysts are a rare source of chronic perianal and perirectal symptoms, and should be included in the differential diagnosis of patients presenting with recurrent sepsis. Diagnosis can often be made with the assistance of MRI imaging and preoperative biopsy is not generally recommended.
Author contributions Substantial contributions to the conception or design of the work; or the acquisition, analysis, or interpretation of data for the work: DP, NP, HO. Drafting the work or revising it critically for important intellectual content: DP, NP, RP. Final approval of the version to be published: DP, NP, HO, RP. Agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved: RP.
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