Pediatric Case Report Granulomatous Inflammation Masquerading as an Infected Urachal Cyst Joseph W. McQuaid, Emily F. Gorman, Emilie K. Johnson, and Bartley G. Cilento Errors in urachal obliteration may result in 4 clinical anomalies: patent urachus, urachal cyst, urachal sinus, or vesicourachal diverticulum. Despite the fact that urachal cysts are one of the more common of these anomalies, most go undetected, presenting in the setting of infection. There are reports in the literature of cysts misdiagnosed as other inflammatory processes; however, the converse is reported with less frequency. We present the case of a 3-year-old girl who was admitted to our institution with a suspected urachal cyst. This was subsequently diagnosed as a granulomatous mass caused by the gram negative bacterium Bartonella. UROLOGY 84: 1496e1498, 2014. 2014 Elsevier Inc.
T
he urachus bridges the fetal bladder and the umbilicus.1 A vestigial remnant, it is evidence of the unification that once existed between 2 separate structures: the cloaca, a precursor to the bladder, and the allantois. Between 4 and 5 months of development, the fetal bladder descends into the pelvis to rest behind the pubis.1 By the completion of this journey, the urachal lumen involutes, leaving behind a fibrous band that occupies the potential midline space between the peritoneum and transversalis fascia.2 Although this process is successful in the vast majority (98%) of cases, errors in urachal obliteration may result in 4 clinical anomalies: patent urachus, urachal cyst, urachal sinus, or vesicourachal diverticulum.2-4
CASE REPORT A 3-year-old girl with no prior urologic or medical history was admitted to our institution with the chief complaint of abdominal pain in September, 2013. Her symptoms began 14 days before presentation when she complained of intermittent suprapubic pain made worse by urination and accompanied by low-grade fevers to 101 F. During the ensuing days, the patient was evaluated by her primary care provider; however, given progression of symptoms, she presented to our emergency department for further evaluation. On physical examination, the patient was afebrile with stable vital signs, demonstrating mild suprapubic fullness with associated tenderness inferior to the umbilicus with Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Urology, Massachusetts General Hospital, Boston, MA; the Department of Pathology, Boston Children’s Hospital, Boston, MA; and the Department of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, MA Address correspondence to: Bartley G. Cilento, M.D., M.P.H., Department of Urology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02468. E-mail: [email protected] Submitted: July 28, 2014, accepted (with revisions): August 5, 2014
1496
ª 2014 Elsevier Inc. All Rights Reserved
deep palpation. Laboratory results revealed a white blood cell count of 14,000/mm3 and electrolytes that were all within normal limits; however, a computed tomography scan at the time demonstrated a 3.6 3.0 4.7 cm complex mass with peripherally enhancing walls and a central area of hypoattenuation (Fig. 1). This immediately abutted the anterior and left lateral aspect of the superior bladder. The patient was admitted to our service for initiation of intravenous antibiotics and infectious disease consultation. She was discharged the next day for completion of her intravenous antibiotic course. Seven weeks later, the patient returned for a delayed exploratory laparotomy, which revealed a 4.2-cm friable, white-tan mass adherent to the left lateral aspect of the bladder and extending to the base of the umbilicus. Although intraoperative findings were suggestive of a large desmoplastic reaction potentially consistent with an infected urachal cyst, careful review of the specimen by pathology was significant for supparative, necrotizing granulomatous inflammation. This focal abscess demonstrated marked lymphoplasmacytic and eosinophilic infiltrates of the bladder wall and adjacent soft tissue (Fig. 2). No acid fast or fungal forms were identified; however, multiple small granular forms consistent with Bartonella appeared on the Steiner stain (Fig. 3). There was no definitive urachal remnant in this tissue.
COMMENT The relative incidence of the 4 urachal anomalies varies among different studies.2,3 However, it is clear that urachal cysts, despite being regarded as one of the more common of these abnormalities, are still rare overall with a demonstrated incidence of 1 in 5000 births.5 Most small cysts go undetected, but children with infected cysts may present with a variety of complaints. These include a painful abdominal mass, fever, irritative voiding symptoms, or in the case of cyst http://dx.doi.org/10.1016/j.urology.2014.08.003 0090-4295/14
Figure 3. Steiner stain revealing multiple small granular forms consistent with Bartonella.
Figure 1. Complex mass with peripherally enhancing walls and a central area of hypoattenuation (3.6 3.0 4.7 cm).
Figure 2. Lymphoplasmacytic and eosinophilic infiltrates of the bladder wall and adjacent soft tissue.
hemorrhage or rupture, peritoneal symptoms.2,4 Infected urachal cysts, if left untreated, may result in a range of complications: fistulization to bowel, bladder, or skin as well as mechanical obstruction of the gastrointestinal or genitourinary tracts.5,6 Given their varied presentation, urachal cysts are often incorrectly diagnosed preoperatively. This rate of misdiagnosis has been reported to be as high as 35%, with perforated appendicitis, noneperforated appendicitis, and incarcerated hernias leading the list of differentials.7 Lessfrequently infected urachal cysts may be mistakenly identified as Meckel diverticulitis, inflammatory bowel disease, or pelvic inflammatory disease.8 Note the converse— incorrect diagnosis of these aforementioned abdominal processes as infected urachal cysts—does not appear to happen with significant frequency; however, there are isolated reports of appendiceal mucoceles, soft tissue UROLOGY 84 (6), 2014
sarcomas, and omphalomesenteric ducts being mistakenly diagnosed as infected urachal remnants.9-11 In the case of this 3-year-old girl, a broad differential was carefully considered, and an infected urachal cyst was considered most likely given the presentation and imaging findings. Yet, on final pathologic review, no urachal remnant could be found—only a necrotizing granuloma. Given that a postoperative tuburculosis skin test was negative for potential mycobacterial infection, it appears that the intracellular gram negative bacterium Bartonella, successfully stained in the initial pathologic specimen, was the inciting agent. This resulted in a necrotizing, granulomatous mass masquerading as an infected urachal cyst. Bartonella is composed of 19 different species including Bartonella henselae, the etiologic agent responsible for catscratch disease (CSD).12 CSD classically presents with tender, swollen lymph nodes, and variably with fever. After exposure, it may take 7-14 days for symptoms to appear and as long as 2 months. Cats are the natural reservoir for B henselae, with fleas serving as a vector of transmission among cats. Kittens are more likely to carry the bacteria in their blood and, therefore, are more likely to transmit the disease. It seems likely that the cat-tohuman transmission occurs with the inoculation of flea feces containing B henselae through a contaminated catscratch wound. CSD occurs mostly in temperate climates and predominantly in the autumn and winter months. Although multiple antibiotics have been used to treat this condition with unclear benefits, most cases are benign and self limiting particularly in healthy individuals. On follow-up evaluation, the patient and her mother did report several recent exposures to cats, making this the most likely mode of transmission of B henselae in this case. Authors have previously reported the presence of xanthogranulomatous disease involving the urachus and muscular wall of the bladder.13 In adults, xanthogranulomatous inflammation previously has been mistaken for a urachal adenocarcinoma.14 However, this represents to our knowledge the first case of a granulomatous mass 1497
masquerading as an infected urachal cyst. Although rare, it should remind us to consider the granulomatous processes in the differential when considering the diagnosis of a urachal anomaly.
References 1. Pazos HM, Costa WS, Sampaio FJ, et al. Structural and ontogenetic study of the urachus in human fetuses. Cells Tissues Organs. 2010; 191:422-430. 2. Cilento BG Jr, Bauer SB, Retik AB, et al. Urachal anomalies: defining the best diagnostic modality. Urology. 1998;52:120-122. 3. McCrystal DJ, Ewing MJ, Lambrianides AL. Acquired urachal pathology: presentation of five cases and a review of the literature. ANZ J Surg. 2001;71:774-776. 4. Bauer SB, Retik AB. Urachal anomalies and related umbilical disorders. Urol Clin North Am. 1978;5:195-211. 5. Allen JW, Song J, Velcek FT. Acute presentation of infected urachal cysts: case report and review of diagnosis and therapeutic interventions. Pediatr Emerg Care. 2004;20:108-111. 6. Coons BJ, Clark PE, Maynes LJ, et al. Sigmoid-urachal-cutaneous fistula in an adult male. Urology. 2009;73:e5-7.
1498
7. Minevich E, Wacksman J, Lewis AG, et al. The infected urachal cyst: primary excision versus a staged approach. The J Urol. 1997; 157:1869-1872. 8. Ogbevoen JO, Jaffe DM, Langer JC. Intraperitoneal rupture of an infected urachal cyst: a rare cause of peritonitis in children. Pediatr Emerg Care. 1996;12:41-43. 9. Perez Fentes DA, Cortegoso Gonzalez M, Punal Pereira A, et al. [Appendiceal mucocele misdiagnosed with infected urachal cyst: a differential diagnosis to keep in mind]. Actas urologicas espanolas. 2009;33:205-208. 10. Tatenuma T, Sakata R, Sugiura S, et al. [Case of abdominal wall malignant peripheral nerve sheath tumor which is difficult to distinguish from a urachal disease]. Nihon Hinyokika Gakkai zasshi. 2013;104:663-666. 11. Iwasaki M, Taira K, Kobayashi H, et al. Umbilical cyst containing ectopic gastric mucosa originating from an omphalomesenteric duct remnant. J Pediatr Surg. 2009;44:2399-2401. 12. Florin TA, Zaoutis TE, Zaoutis LB. Beyond cat scratch disease: widening spectrum of Bartonella henselae infection. Pediatrics. 2008;121:e1413-e1425. 13. Carrere W, Gutierrez R, Umbert B, et al. Urachal xanthogranulomatous disease. Br J Urol. 1996;77:612-613. 14. Kuo TL, Cheng C. Xanthogranulomatous inflammation of urachus mimicking urachal carcinoma. Urology. 2009;73:443.e13-443.e14.
UROLOGY 84 (6), 2014
T
he urachus bridges the fetal bladder and the umbilicus.1 A vestigial remnant, it is evidence of the unification that once existed between 2 separate structures: the cloaca, a precursor to the bladder, and the allantois. Between 4 and 5 months of development, the fetal bladder descends into the pelvis to rest behind the pubis.1 By the completion of this journey, the urachal lumen involutes, leaving behind a fibrous band that occupies the potential midline space between the peritoneum and transversalis fascia.2 Although this process is successful in the vast majority (98%) of cases, errors in urachal obliteration may result in 4 clinical anomalies: patent urachus, urachal cyst, urachal sinus, or vesicourachal diverticulum.2-4
CASE REPORT A 3-year-old girl with no prior urologic or medical history was admitted to our institution with the chief complaint of abdominal pain in September, 2013. Her symptoms began 14 days before presentation when she complained of intermittent suprapubic pain made worse by urination and accompanied by low-grade fevers to 101 F. During the ensuing days, the patient was evaluated by her primary care provider; however, given progression of symptoms, she presented to our emergency department for further evaluation. On physical examination, the patient was afebrile with stable vital signs, demonstrating mild suprapubic fullness with associated tenderness inferior to the umbilicus with Financial Disclosure: The authors declare that they have no relevant financial interests. From the Department of Urology, Massachusetts General Hospital, Boston, MA; the Department of Pathology, Boston Children’s Hospital, Boston, MA; and the Department of Urology, Boston Children’s Hospital, Harvard Medical School, Boston, MA Address correspondence to: Bartley G. Cilento, M.D., M.P.H., Department of Urology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02468. E-mail: [email protected] Submitted: July 28, 2014, accepted (with revisions): August 5, 2014
1496
ª 2014 Elsevier Inc. All Rights Reserved
deep palpation. Laboratory results revealed a white blood cell count of 14,000/mm3 and electrolytes that were all within normal limits; however, a computed tomography scan at the time demonstrated a 3.6 3.0 4.7 cm complex mass with peripherally enhancing walls and a central area of hypoattenuation (Fig. 1). This immediately abutted the anterior and left lateral aspect of the superior bladder. The patient was admitted to our service for initiation of intravenous antibiotics and infectious disease consultation. She was discharged the next day for completion of her intravenous antibiotic course. Seven weeks later, the patient returned for a delayed exploratory laparotomy, which revealed a 4.2-cm friable, white-tan mass adherent to the left lateral aspect of the bladder and extending to the base of the umbilicus. Although intraoperative findings were suggestive of a large desmoplastic reaction potentially consistent with an infected urachal cyst, careful review of the specimen by pathology was significant for supparative, necrotizing granulomatous inflammation. This focal abscess demonstrated marked lymphoplasmacytic and eosinophilic infiltrates of the bladder wall and adjacent soft tissue (Fig. 2). No acid fast or fungal forms were identified; however, multiple small granular forms consistent with Bartonella appeared on the Steiner stain (Fig. 3). There was no definitive urachal remnant in this tissue.
COMMENT The relative incidence of the 4 urachal anomalies varies among different studies.2,3 However, it is clear that urachal cysts, despite being regarded as one of the more common of these abnormalities, are still rare overall with a demonstrated incidence of 1 in 5000 births.5 Most small cysts go undetected, but children with infected cysts may present with a variety of complaints. These include a painful abdominal mass, fever, irritative voiding symptoms, or in the case of cyst http://dx.doi.org/10.1016/j.urology.2014.08.003 0090-4295/14
Figure 3. Steiner stain revealing multiple small granular forms consistent with Bartonella.
Figure 1. Complex mass with peripherally enhancing walls and a central area of hypoattenuation (3.6 3.0 4.7 cm).
Figure 2. Lymphoplasmacytic and eosinophilic infiltrates of the bladder wall and adjacent soft tissue.
hemorrhage or rupture, peritoneal symptoms.2,4 Infected urachal cysts, if left untreated, may result in a range of complications: fistulization to bowel, bladder, or skin as well as mechanical obstruction of the gastrointestinal or genitourinary tracts.5,6 Given their varied presentation, urachal cysts are often incorrectly diagnosed preoperatively. This rate of misdiagnosis has been reported to be as high as 35%, with perforated appendicitis, noneperforated appendicitis, and incarcerated hernias leading the list of differentials.7 Lessfrequently infected urachal cysts may be mistakenly identified as Meckel diverticulitis, inflammatory bowel disease, or pelvic inflammatory disease.8 Note the converse— incorrect diagnosis of these aforementioned abdominal processes as infected urachal cysts—does not appear to happen with significant frequency; however, there are isolated reports of appendiceal mucoceles, soft tissue UROLOGY 84 (6), 2014
sarcomas, and omphalomesenteric ducts being mistakenly diagnosed as infected urachal remnants.9-11 In the case of this 3-year-old girl, a broad differential was carefully considered, and an infected urachal cyst was considered most likely given the presentation and imaging findings. Yet, on final pathologic review, no urachal remnant could be found—only a necrotizing granuloma. Given that a postoperative tuburculosis skin test was negative for potential mycobacterial infection, it appears that the intracellular gram negative bacterium Bartonella, successfully stained in the initial pathologic specimen, was the inciting agent. This resulted in a necrotizing, granulomatous mass masquerading as an infected urachal cyst. Bartonella is composed of 19 different species including Bartonella henselae, the etiologic agent responsible for catscratch disease (CSD).12 CSD classically presents with tender, swollen lymph nodes, and variably with fever. After exposure, it may take 7-14 days for symptoms to appear and as long as 2 months. Cats are the natural reservoir for B henselae, with fleas serving as a vector of transmission among cats. Kittens are more likely to carry the bacteria in their blood and, therefore, are more likely to transmit the disease. It seems likely that the cat-tohuman transmission occurs with the inoculation of flea feces containing B henselae through a contaminated catscratch wound. CSD occurs mostly in temperate climates and predominantly in the autumn and winter months. Although multiple antibiotics have been used to treat this condition with unclear benefits, most cases are benign and self limiting particularly in healthy individuals. On follow-up evaluation, the patient and her mother did report several recent exposures to cats, making this the most likely mode of transmission of B henselae in this case. Authors have previously reported the presence of xanthogranulomatous disease involving the urachus and muscular wall of the bladder.13 In adults, xanthogranulomatous inflammation previously has been mistaken for a urachal adenocarcinoma.14 However, this represents to our knowledge the first case of a granulomatous mass 1497
masquerading as an infected urachal cyst. Although rare, it should remind us to consider the granulomatous processes in the differential when considering the diagnosis of a urachal anomaly.
References 1. Pazos HM, Costa WS, Sampaio FJ, et al. Structural and ontogenetic study of the urachus in human fetuses. Cells Tissues Organs. 2010; 191:422-430. 2. Cilento BG Jr, Bauer SB, Retik AB, et al. Urachal anomalies: defining the best diagnostic modality. Urology. 1998;52:120-122. 3. McCrystal DJ, Ewing MJ, Lambrianides AL. Acquired urachal pathology: presentation of five cases and a review of the literature. ANZ J Surg. 2001;71:774-776. 4. Bauer SB, Retik AB. Urachal anomalies and related umbilical disorders. Urol Clin North Am. 1978;5:195-211. 5. Allen JW, Song J, Velcek FT. Acute presentation of infected urachal cysts: case report and review of diagnosis and therapeutic interventions. Pediatr Emerg Care. 2004;20:108-111. 6. Coons BJ, Clark PE, Maynes LJ, et al. Sigmoid-urachal-cutaneous fistula in an adult male. Urology. 2009;73:e5-7.
1498
7. Minevich E, Wacksman J, Lewis AG, et al. The infected urachal cyst: primary excision versus a staged approach. The J Urol. 1997; 157:1869-1872. 8. Ogbevoen JO, Jaffe DM, Langer JC. Intraperitoneal rupture of an infected urachal cyst: a rare cause of peritonitis in children. Pediatr Emerg Care. 1996;12:41-43. 9. Perez Fentes DA, Cortegoso Gonzalez M, Punal Pereira A, et al. [Appendiceal mucocele misdiagnosed with infected urachal cyst: a differential diagnosis to keep in mind]. Actas urologicas espanolas. 2009;33:205-208. 10. Tatenuma T, Sakata R, Sugiura S, et al. [Case of abdominal wall malignant peripheral nerve sheath tumor which is difficult to distinguish from a urachal disease]. Nihon Hinyokika Gakkai zasshi. 2013;104:663-666. 11. Iwasaki M, Taira K, Kobayashi H, et al. Umbilical cyst containing ectopic gastric mucosa originating from an omphalomesenteric duct remnant. J Pediatr Surg. 2009;44:2399-2401. 12. Florin TA, Zaoutis TE, Zaoutis LB. Beyond cat scratch disease: widening spectrum of Bartonella henselae infection. Pediatrics. 2008;121:e1413-e1425. 13. Carrere W, Gutierrez R, Umbert B, et al. Urachal xanthogranulomatous disease. Br J Urol. 1996;77:612-613. 14. Kuo TL, Cheng C. Xanthogranulomatous inflammation of urachus mimicking urachal carcinoma. Urology. 2009;73:443.e13-443.e14.
UROLOGY 84 (6), 2014
