Surg Today (2015) 45:101–104 DOI 10.1007/s00595-014-0960-y
CASE REPORT
Enlarging lymphoepithelial cyst of the pancreas during 12 months of observation: report of a case Daisuke Satoh • Hiroshi Sadamori • Takahito Yagi • Toshiyoshi Fujiwara
Received: 9 March 2012 / Accepted: 20 August 2013 / Published online: 9 July 2014 Ó Springer Japan 2014
Abstract Pancreatic lymphoepithelial cysts (LECs) are rare benign pancreatic cystic lesions, the etiology of which is unknown. We report a case of a pancreatic LEC, discovered incidentally in a 63-year-old man during a followup clinic visit for an abdominal aneurysm. Computed tomography showed a multilocular cyst, 60-mm diameter in the body of the pancreas. This cyst increased from 6.0 to 6.5 cm during 12 months of observation. Part of the cyst was also visualized on positron emission tomography imaging. Since a pancreatic cystic neoplasm could not be ruled out, we performed distal pancreatectomy and postoperative pathological examination confirmed that the lesion was an LEC of the pancreas. Despite the conclusive postoperative findings, resection is unavoidable when a true pancreatic neoplasm cannot be excluded. Keyword
Pancreatic lymphoepithelial cysts
Introduction With advances in imaging technology, cystic lesions of the pancreas are being detected with increasing frequency. Pancreatic lymphoepithelial cysts (LECs) were first described in 1985 by Luchtrath and Schriefers [1], as ‘‘true cystic lesions filled with keratinized material, lined by mature, keratinizing squamous epithelium, and surrounded by lymphoid tissue containing few lymphoid follicles.’’
D. Satoh (&) H. Sadamori T. Yagi T. Fujiwara Department of Gastroenterological Surgery, Transplant, and Surgical Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan e-mail: [email protected]
LECs are a rare type of true cyst that can mimic pseudocysts and cystic neoplasms. The differential diagnosis is often difficult because of the various manifestations of LECs on diagnostic images; therefore, surgery is usually indicated. We report a case of pancreatic LEC, which increased in size under observation, the diagnosis of which was ultimately confirmed after surgery.
Case report A 63-year-old man was referred to our institution for evaluation of a pancreatic mass found incidentally during routine follow-up for a past abdominal aortic aneurysm. He had no history of pancreatitis. Abdominal computed tomography (CT) showed a 60 9 30 mm cystic lesion in the pancreatic body. Physical examination of the abdomen showed no abnormalities. Laboratory evaluation demonstrated a serum carbohydrate antigen (CA) 19-9 level of 85.5 U/ml (reference range 0–30 U/ml), but the other values were normal. Abdominal contrast-enhanced CT showed a non-enhanced, well-circumscribed multilocular cyst with no solid component (Fig. 1). Magnetic resonance imaging (MRI) revealed low intensity on fat-suppressed T1-weighted imaging and high intensity on fat-suppressed T2-weighted imaging. A diffusion-weighted (DWI) MRI showed a high-intensity area in the body of the pancreas (Fig. 2). Endoscopic retrograde cholangiopancreatography revealed no dilatation of the main pancreatic duct and no continuity between the pancreatic duct and the cyst. Endoscopic ultrasound showed a multilocular cyst with a granular echotexture adjacent to the pancreatic body. Endoscopic ultrasound-guided fine-needle biopsy (FNA) was performed via a transgastric approach and its cytology revealed atypical cells. Part of the cyst was visualized on
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Fig. 1 a Abdominal computed tomography (CT) showed a 60 9 30 mm multilocular cyst in the head of the pancreas. b Abdominal contrastenhanced CT showed a nonenhanced, well-circumscribed multilocular cyst with no solid component
Fig. 2 Magnetic resonance imaging (MRI) findings showing a low intensity on fat-suppressed T1-weighted imaging and b high intensity on fatsuppressed T2-weighted imaging. c Diffusion-weighted (DWI) MRI showed a high-intensity area in the body of the pancreas
positron emission tomography (PET) imaging (maximum standardized uptake value [SUV max] 2.7) (Fig. 3). The patient was followed up 12 months later with repeat MRI imaging, which showed an increase in size from 6.0 to 6.5 cm. Based on these findings, we could not exclude malignant disease and decided to operate. We performed distal pancreatectomy with splenectomy through an open laparotomy. Because the CT scan showed
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that the mass was in close proximity to the splenic artery and vein, we did not preserve the spleen. Intraoperative exploration revealed that most of the mass was located on the dorsal side of the pancreas. On gross examination, the specimen consisted of a multilocular cyst, 6-cm diameter, which was covered with a thin capsule, and contained yellowish-white material (Fig. 4). Histologic examination revealed a fibrous wall with scattered regions of lymphoid
Surg Today (2015) 45:101–104
Fig. 3 Part of the cyst was visualized on PET imaging (SUV max 2.7)
Fig. 4 Grossly, the specimen comprised a multilocular cyst, 6 cm in diameter, covered with a thin capsule, and containing yellowish-white material
cells and a squamous epithelial cyst lining (Fig. 5). Based on these findings, the pathologic diagnosis was LEC.
Discussion Pancreatic LECs are rare benign cysts, typically lined with mature, keratinized stratified squamous epithelium surrounded by lymphoid tissue. These cysts represent approximately 0.5 % of all pancreatic cystic lesions and tend to arise in middle-aged to elderly men [2]. LECs are often asymptomatic or nonspecific, and physical
103
Fig. 5 Histologic examination revealed a fibrous wall with scattered regions of lymphoid cells and a squamous epithelial cyst lining
examination is usually unremarkable, as in our patient. Laboratory findings often show an elevated serum CA 19-9 [3, 4]. The cysts may be multilocular or unilocular and the mean size is 4.7 cm [5, 6]. CT scans usually show a lowattenuation mass with a thin enhancing rim and focal wall calcification. MRI often shows low intensity on T1weighted imaging and high intensity on T2-weighted imaging, due to the keratinous content of the cyst. Diffusion-weighted (DWI) MRI is especially beneficial in the detection of LECs [7]. In the present case, the clinical characteristics were unique in that the cyst increased in size under observation and that part of it was visualized on PET imaging. Maekawa et al. [8] also recently described a rare case of LEC with an intracystic papillary growth which was visualized on PET scans. To our knowledge, enlargement of an LEC as observed in our patient has never before been reported, although malignant transformation of an LEC has also never been reported. The pathogenesis and histogenesis of LECs are both unclear, although several hypotheses have been proposed [4, 9]. One hypothesis suggests that the cyst may represent squamous dysplasia of an obstructive and dilated pancreatic duct; another suggests that the cyst may be derived from the remnant of the branchial cleft misplaced in the pancreas during embryogenesis; another suggests that the cyst may arise from an intrapancreatic accessory spleen; and the most widely accepted hypothesis suggests that the cyst arises from a benign epithelial inclusion or an ectopic pancreas in a peripancreatic lymph node, which subsequently invades the pancreas. Establishing a preoperative diagnosis of LECs is difficult because radiological and clinical criteria are not always reliable. The differential diagnosis includes pseudocysts, retroperitoneal cysts, branch duct-type intraductal papillary
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mucinous neoplasms, and mucinous cystic neoplasms. FNA can be helpful in the diagnosis of LEC when squamous cells or keratinous materials are present, although FNA can yield inconclusive results, especially if atypical glandular cells are present [10–12]. Furthermore, similar findings including a mixture of squamous cells and lymphocytes have been reported in other pancreatic lesions such as dermoid cysts, splenic epidermoid cysts, adenosquamous carcinoma, and metastatic squamous cell carcinoma [12]. Usually, surgical resection should be carried out without performing FNA, because the leakage of fluid by FNA might carry a risk of dissemination if the lesion was a malignant neoplasm or intraductal papillary mucinous carcinoma. In the present case, we decided to perform FNA to avoid surgery and make a precise preoperative diagnosis, in consideration of the patient’s abdominal aneurysm. Because the CT scan showed that the cyst was adhered to the stomach, we thought there were few risks of dissemination from an FNA. Therefore, the patient underwent FNA twice, but a diagnosis of LEC could not be confirmed due to the existence of atypical cells. Considering the elevated serum CA 19-9, the PET visualization of part of the lesion, and the growth of the lesion over 12 months, we could not rule out the possibility of malignancy completely. Thus, we decided to operate to remove this cystic pancreatic lesion. In conclusion, the differential diagnosis in this case was difficult. Possible malignancy could not be ruled out because the pancreatic LEC enlarged while under observation, and was visualized on PET imaging. In such a case, resection is unavoidable. Conflict of interest conflict of interest.
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Daisuke Satoh and his co-authors have no
References 1. Luchtrath H, Schriefers KH. A pancreatic cyst with features of a so-called branchiogenic cyst. Patholog. 1985;6:217–9. 2. Adsay NV, Husth F, Cheng JD, Bejarano PA, Lauwers GY, Batts KP, et al. Lymphoepithelial cysts of the pancreas: a report of 12 cases and a review of the literature. Mod Pathol. 2002;15:492–501. 3. Yamaguchi T, Takahashi H, Kagawa R, Takeda R, Sakata S, Yamamoto M, et al. Lymphoepithelial cyst of pancreas associated with elevated CA 19-9 levels. J Hepatobiliary Pancreat Surg. 2008;15:652–4. 4. Micke O, Schafer U, Willich N. Persistent elevation of CA 19-9 levels in a patient with an extended retroperitoneal dermoid. Anticancer Res. 1999;19:2717–20. 5. Adsay NV, Hasteh F, Cheng JD, Klimstra DS. Squamous-lined cysts of pancreas: lymphoepithelial cysts, dermoid cysts (teratomas), and accessory-splenic epidermoid cysts. Semin Diagn Pathol. 2000;17:56–65. 6. Fukunaga N, Ishikawa M, Minato T, Yamamura Y, Ishikura H, Ichimori T, et al. Lymphoepithelial cyst of the pancreas that difficult to distinguish from branch duct-type intraductal papillary mucinous neoplasm; report of a case. Surg Today. 2009;39:901–4. 7. Nam SJ, Hwang HK, Kim H, Yu JS, Yoon DS, Chung JJ, et al. Lymphoepithelial cysts in the pancreas: MRI of two cases with emphasis of discussion-weighted imaging characteristics. J Magn Reson Imaging. 2010;32:692–6. 8. Hiroshi M, Hisashi Y, Yoshihiro K, Hajime O, Matsumi S, Koichi S, et al. Pancreatic lymphoepithelial cyst with intracystic papillary projection. Report of a case. JOP J Pancreas. 2009;10:694–6. 9. Truong LD, Stewart MG, Hao H, Yutani C, Jordan PH. Comprehensive characterization of lymphoepithelial cyst associated with the pancreas. Am J Surg. 1995;170:27–32. 10. Sobia A, Neal W, Chris SJ, Henning G. EUS-guiding Trucut biopsies may enable the diagnosis of lymphoepithelial cycts of the pancreas. Report of two cases. JOP J Pancreas. 2009;10:409–12. 11. Cappellari JO. Fine-needle aspiration cytology of pancreatic lymphoepithelial cycts. Diagn Cytopathol. 1993;9:77–81. 12. Mitchell ML. Fine needle aspiration biopsy of peripancreatic lymphoepithelial cycts. Acta Cytol. 1990;34:462–3.
CASE REPORT
Enlarging lymphoepithelial cyst of the pancreas during 12 months of observation: report of a case Daisuke Satoh • Hiroshi Sadamori • Takahito Yagi • Toshiyoshi Fujiwara
Received: 9 March 2012 / Accepted: 20 August 2013 / Published online: 9 July 2014 Ó Springer Japan 2014
Abstract Pancreatic lymphoepithelial cysts (LECs) are rare benign pancreatic cystic lesions, the etiology of which is unknown. We report a case of a pancreatic LEC, discovered incidentally in a 63-year-old man during a followup clinic visit for an abdominal aneurysm. Computed tomography showed a multilocular cyst, 60-mm diameter in the body of the pancreas. This cyst increased from 6.0 to 6.5 cm during 12 months of observation. Part of the cyst was also visualized on positron emission tomography imaging. Since a pancreatic cystic neoplasm could not be ruled out, we performed distal pancreatectomy and postoperative pathological examination confirmed that the lesion was an LEC of the pancreas. Despite the conclusive postoperative findings, resection is unavoidable when a true pancreatic neoplasm cannot be excluded. Keyword
Pancreatic lymphoepithelial cysts
Introduction With advances in imaging technology, cystic lesions of the pancreas are being detected with increasing frequency. Pancreatic lymphoepithelial cysts (LECs) were first described in 1985 by Luchtrath and Schriefers [1], as ‘‘true cystic lesions filled with keratinized material, lined by mature, keratinizing squamous epithelium, and surrounded by lymphoid tissue containing few lymphoid follicles.’’
D. Satoh (&) H. Sadamori T. Yagi T. Fujiwara Department of Gastroenterological Surgery, Transplant, and Surgical Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, 2-5-1 Shikata-cho, Okayama 700-8558, Japan e-mail: [email protected]
LECs are a rare type of true cyst that can mimic pseudocysts and cystic neoplasms. The differential diagnosis is often difficult because of the various manifestations of LECs on diagnostic images; therefore, surgery is usually indicated. We report a case of pancreatic LEC, which increased in size under observation, the diagnosis of which was ultimately confirmed after surgery.
Case report A 63-year-old man was referred to our institution for evaluation of a pancreatic mass found incidentally during routine follow-up for a past abdominal aortic aneurysm. He had no history of pancreatitis. Abdominal computed tomography (CT) showed a 60 9 30 mm cystic lesion in the pancreatic body. Physical examination of the abdomen showed no abnormalities. Laboratory evaluation demonstrated a serum carbohydrate antigen (CA) 19-9 level of 85.5 U/ml (reference range 0–30 U/ml), but the other values were normal. Abdominal contrast-enhanced CT showed a non-enhanced, well-circumscribed multilocular cyst with no solid component (Fig. 1). Magnetic resonance imaging (MRI) revealed low intensity on fat-suppressed T1-weighted imaging and high intensity on fat-suppressed T2-weighted imaging. A diffusion-weighted (DWI) MRI showed a high-intensity area in the body of the pancreas (Fig. 2). Endoscopic retrograde cholangiopancreatography revealed no dilatation of the main pancreatic duct and no continuity between the pancreatic duct and the cyst. Endoscopic ultrasound showed a multilocular cyst with a granular echotexture adjacent to the pancreatic body. Endoscopic ultrasound-guided fine-needle biopsy (FNA) was performed via a transgastric approach and its cytology revealed atypical cells. Part of the cyst was visualized on
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Surg Today (2015) 45:101–104
Fig. 1 a Abdominal computed tomography (CT) showed a 60 9 30 mm multilocular cyst in the head of the pancreas. b Abdominal contrastenhanced CT showed a nonenhanced, well-circumscribed multilocular cyst with no solid component
Fig. 2 Magnetic resonance imaging (MRI) findings showing a low intensity on fat-suppressed T1-weighted imaging and b high intensity on fatsuppressed T2-weighted imaging. c Diffusion-weighted (DWI) MRI showed a high-intensity area in the body of the pancreas
positron emission tomography (PET) imaging (maximum standardized uptake value [SUV max] 2.7) (Fig. 3). The patient was followed up 12 months later with repeat MRI imaging, which showed an increase in size from 6.0 to 6.5 cm. Based on these findings, we could not exclude malignant disease and decided to operate. We performed distal pancreatectomy with splenectomy through an open laparotomy. Because the CT scan showed
123
that the mass was in close proximity to the splenic artery and vein, we did not preserve the spleen. Intraoperative exploration revealed that most of the mass was located on the dorsal side of the pancreas. On gross examination, the specimen consisted of a multilocular cyst, 6-cm diameter, which was covered with a thin capsule, and contained yellowish-white material (Fig. 4). Histologic examination revealed a fibrous wall with scattered regions of lymphoid
Surg Today (2015) 45:101–104
Fig. 3 Part of the cyst was visualized on PET imaging (SUV max 2.7)
Fig. 4 Grossly, the specimen comprised a multilocular cyst, 6 cm in diameter, covered with a thin capsule, and containing yellowish-white material
cells and a squamous epithelial cyst lining (Fig. 5). Based on these findings, the pathologic diagnosis was LEC.
Discussion Pancreatic LECs are rare benign cysts, typically lined with mature, keratinized stratified squamous epithelium surrounded by lymphoid tissue. These cysts represent approximately 0.5 % of all pancreatic cystic lesions and tend to arise in middle-aged to elderly men [2]. LECs are often asymptomatic or nonspecific, and physical
103
Fig. 5 Histologic examination revealed a fibrous wall with scattered regions of lymphoid cells and a squamous epithelial cyst lining
examination is usually unremarkable, as in our patient. Laboratory findings often show an elevated serum CA 19-9 [3, 4]. The cysts may be multilocular or unilocular and the mean size is 4.7 cm [5, 6]. CT scans usually show a lowattenuation mass with a thin enhancing rim and focal wall calcification. MRI often shows low intensity on T1weighted imaging and high intensity on T2-weighted imaging, due to the keratinous content of the cyst. Diffusion-weighted (DWI) MRI is especially beneficial in the detection of LECs [7]. In the present case, the clinical characteristics were unique in that the cyst increased in size under observation and that part of it was visualized on PET imaging. Maekawa et al. [8] also recently described a rare case of LEC with an intracystic papillary growth which was visualized on PET scans. To our knowledge, enlargement of an LEC as observed in our patient has never before been reported, although malignant transformation of an LEC has also never been reported. The pathogenesis and histogenesis of LECs are both unclear, although several hypotheses have been proposed [4, 9]. One hypothesis suggests that the cyst may represent squamous dysplasia of an obstructive and dilated pancreatic duct; another suggests that the cyst may be derived from the remnant of the branchial cleft misplaced in the pancreas during embryogenesis; another suggests that the cyst may arise from an intrapancreatic accessory spleen; and the most widely accepted hypothesis suggests that the cyst arises from a benign epithelial inclusion or an ectopic pancreas in a peripancreatic lymph node, which subsequently invades the pancreas. Establishing a preoperative diagnosis of LECs is difficult because radiological and clinical criteria are not always reliable. The differential diagnosis includes pseudocysts, retroperitoneal cysts, branch duct-type intraductal papillary
123
104
Surg Today (2015) 45:101–104
mucinous neoplasms, and mucinous cystic neoplasms. FNA can be helpful in the diagnosis of LEC when squamous cells or keratinous materials are present, although FNA can yield inconclusive results, especially if atypical glandular cells are present [10–12]. Furthermore, similar findings including a mixture of squamous cells and lymphocytes have been reported in other pancreatic lesions such as dermoid cysts, splenic epidermoid cysts, adenosquamous carcinoma, and metastatic squamous cell carcinoma [12]. Usually, surgical resection should be carried out without performing FNA, because the leakage of fluid by FNA might carry a risk of dissemination if the lesion was a malignant neoplasm or intraductal papillary mucinous carcinoma. In the present case, we decided to perform FNA to avoid surgery and make a precise preoperative diagnosis, in consideration of the patient’s abdominal aneurysm. Because the CT scan showed that the cyst was adhered to the stomach, we thought there were few risks of dissemination from an FNA. Therefore, the patient underwent FNA twice, but a diagnosis of LEC could not be confirmed due to the existence of atypical cells. Considering the elevated serum CA 19-9, the PET visualization of part of the lesion, and the growth of the lesion over 12 months, we could not rule out the possibility of malignancy completely. Thus, we decided to operate to remove this cystic pancreatic lesion. In conclusion, the differential diagnosis in this case was difficult. Possible malignancy could not be ruled out because the pancreatic LEC enlarged while under observation, and was visualized on PET imaging. In such a case, resection is unavoidable. Conflict of interest conflict of interest.
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Daisuke Satoh and his co-authors have no
References 1. Luchtrath H, Schriefers KH. A pancreatic cyst with features of a so-called branchiogenic cyst. Patholog. 1985;6:217–9. 2. Adsay NV, Husth F, Cheng JD, Bejarano PA, Lauwers GY, Batts KP, et al. Lymphoepithelial cysts of the pancreas: a report of 12 cases and a review of the literature. Mod Pathol. 2002;15:492–501. 3. Yamaguchi T, Takahashi H, Kagawa R, Takeda R, Sakata S, Yamamoto M, et al. Lymphoepithelial cyst of pancreas associated with elevated CA 19-9 levels. J Hepatobiliary Pancreat Surg. 2008;15:652–4. 4. Micke O, Schafer U, Willich N. Persistent elevation of CA 19-9 levels in a patient with an extended retroperitoneal dermoid. Anticancer Res. 1999;19:2717–20. 5. Adsay NV, Hasteh F, Cheng JD, Klimstra DS. Squamous-lined cysts of pancreas: lymphoepithelial cysts, dermoid cysts (teratomas), and accessory-splenic epidermoid cysts. Semin Diagn Pathol. 2000;17:56–65. 6. Fukunaga N, Ishikawa M, Minato T, Yamamura Y, Ishikura H, Ichimori T, et al. Lymphoepithelial cyst of the pancreas that difficult to distinguish from branch duct-type intraductal papillary mucinous neoplasm; report of a case. Surg Today. 2009;39:901–4. 7. Nam SJ, Hwang HK, Kim H, Yu JS, Yoon DS, Chung JJ, et al. Lymphoepithelial cysts in the pancreas: MRI of two cases with emphasis of discussion-weighted imaging characteristics. J Magn Reson Imaging. 2010;32:692–6. 8. Hiroshi M, Hisashi Y, Yoshihiro K, Hajime O, Matsumi S, Koichi S, et al. Pancreatic lymphoepithelial cyst with intracystic papillary projection. Report of a case. JOP J Pancreas. 2009;10:694–6. 9. Truong LD, Stewart MG, Hao H, Yutani C, Jordan PH. Comprehensive characterization of lymphoepithelial cyst associated with the pancreas. Am J Surg. 1995;170:27–32. 10. Sobia A, Neal W, Chris SJ, Henning G. EUS-guiding Trucut biopsies may enable the diagnosis of lymphoepithelial cycts of the pancreas. Report of two cases. JOP J Pancreas. 2009;10:409–12. 11. Cappellari JO. Fine-needle aspiration cytology of pancreatic lymphoepithelial cycts. Diagn Cytopathol. 1993;9:77–81. 12. Mitchell ML. Fine needle aspiration biopsy of peripancreatic lymphoepithelial cycts. Acta Cytol. 1990;34:462–3.
