Solitary true cyst of the pancreas in an adult: report of a case

Simple mucinous cyst: another potential cancer precursor in the pancreas? Case report with molecular characterization and systematic review of the literature

Cystic lesions of the pancreas may range from benign to precursors of pancreatic cancer. Simple mucinous cyst (SMC) is larger than 1 cm, has a gastric-type flat mucinous lining, and minimal atypia without ovarian-type stroma. We report a new case of pancreatic SMC, coupling a systematic review of the English literature mainly focused on their clinic-pathological features. We reviewed 103 cases of SMC in adults (73 women), averaging 57 (range, 26–70) years. The SMCs were located in the body-tail region of the pancreas in 60 (58%) cases, presenting as single cystic lesions in 94% of cases; 43% of patients were asymptomatic. A preoperative fine-needle aspiration of the cyst fluid detected amylase and carcinoembryonic antigen positivity in 71% and 76% of cases, respectively. Patients underwent surgery mostly for suspected malignancy; in 83% of cases, a standard pancreatic resection was performed. Mean SMC size was 4.9 (range, 1.5–12.0) cm. Mucins MUC5AC and MUC6 resulted positive in 77% and 81% of cases performed, respectively, whereas MUC2 was negative in all but one patient. The SMC from our institution was characterized by a KRAS somatic mutation. The diagnosis of SMC should be considered when a solitary pancreatic cyst larger than 1 cm is detected in asymptomatic patients. To establish a correct diagnosis, an extensive histologic/immunohistochemical analysis is essential. The presence of a KRAS mutation highlights that SMC may represent another potential pancreatic cancer precursor.

Laparoscopic spleen-preserving distal pancreatectomy in a solitary true pancreatic cyst

BACKGROUND

Solitary true pancreatic cysts (STPCs), or epithelial cysts, are benign lesions that are extremely rare in adult patients. Advances in radiographic techniques have improved the ability to identify pancreatic cystic lesions. We report a case of a large and symptomatic STPC in a 47-year-old female patient who was treated successfully with spleen-preserving laparoscopic distal pancreatectomy. We also review the clinical and pathologic features of all reported STPCs within the past 25 years.

DATABASE

To compose the review, we did a search of the international literature for STPCs that had occurred in adults. Fourteen related articles were found describing cases of STPCs. Clinical and pathologic information was collected for all of the reported pancreatic cysts, and a database was formed. STPCs are detected more frequently in women than in men. The mean age of occurrence is 43.2 years, and the mean cyst size is 5.6 cm. Fifty percent of true cysts are located in the head of the pancreas. Size and site are responsible for the symptoms caused, although 22.8% were asymptomatic. Diagnosis was made postoperatively in all cases by histopathologic studies. No case of malignancy was reported in any STPC.

CONCLUSIONS

STPCs are rare and benign lesions commonly discovered incidentally during abdominal imaging. Surgical treatment is considered the appropriate therapy for large and symptomatic STPCs. The definitive diagnosis is established by histopathologic and immunohistochemical studies.

Isolated pancreatic tuberculosis: a case report and radiological comparison with cystic pancreatic lesions

Pancreatic tuberculosis is rare and can occur in the absence of evidence of tuberculosis elsewhere in the body. Here we review the radiological appearance of pancreatic tuberculosis and compare it with other cystic pancreatic lesions, including common lesions (pseudocysts, serous or mucinous cystadenomas, intraductal papillary mucinous neoplasm) and rare lesions such as solid pseudopapillary tumors, etc. Their typical localizations within the pancreas and their malignant potential are presented. Knowledge of these can assist radiologists and clinicians in selecting the best approach towards making the correct diagnosis.

A new case of solitary true pancreatic cyst

A true cyst of the pancreas is extremely rare, and few cases have been reported in adult patients. The authors report a new case of this rare pathological entity. A 35-year-old male patient was admitted to our unit with a cystic mass, about 6cm in diameter, located in the pancreatic head, in proximity to the duodenum, vena cava, biliary tree and right kidney. Clinical features and imagery were suggestive for a benign neoplasm, as did surgical findings. Cystoduodenostomy was done. Histological finding revealed a cyst lined by cuboidal epithelium without morphologic alterations. Analysis of the cyst fluid showed a high level of CA 19-9 (10,000Uml(-1)). After 1-year follow-up, the patient was found to be doing well without any abdominal symptoms. Ultrasound images revealed no cyst recurrence.

Mucin Secreting Cystic Lesions of the Pancreas: Treatment by Enucleation

Ninety per cent of pancreatic cysts are inflammatory pseudocysts. The other 10 per cent are congenital or neoplastic and include congenital true cysts, retention cysts, lymphoepithelial cysts, the mucinous cystadenoma, mucinous cystadenocarcinoma, and serous microcystic cystadenomas and the more recently described intraductal papillary mucin-secreting neoplasms. The advent of computerized tomographic scanning, endoscopic retrograde cholangiopancreatography (ERCP), and endoscopic ultrasonography (EUS) has brought many of these lesions to light when they are minimally symptomatic or are incidentally found while investigating unrelated problems. If there is any suspicion of actual or potentially malignant disease, then total excision of the lesion with part of or the entire pancreas is indicated to achieve a likely cure, as survival is better than for the more common ductal adenocarcinomas. There are few reliable preoperative studies to distinguish accurately the etiology and prognosis of this spectrum of cystic lesions, and usually the actual diagnosis is made only at the time of operation or histopathologic examination after the cystic lesion has been biopsied or excised. If a cyst is confirmed to be totally benign, as in the congenital true cyst, lymphoepithelial cyst, or a benign mucinous cyst, they may lend themselves to nonoperative observation or excision without sacrifice of pancreatic parenchyma. However, many mucin-producing cystic lesions may evolve into a dysplastic or invasive malignant lesion requiring more aggressive resective treatment, and it is important not to miss that diagnosis early when cure is still possible. This report presents four benign mucin-secreting cysts treated by local excision. All four were in the head of the pancreas and communicated with the main pancreatic duct and lacked ovarian-type stroma, thus categorizing them as side-branch intraductal papillary mucinous neoplasms. These lesions were able to be easily dissected out of the pancreas with only one patient developing a transient pancreatic fistula. Intraoperative and final histopathology confirmed the benign status, and these patients have remained disease free 3 to 5 years postoperatively. A review of benign tumors reported to have been treated by cyst enucleation in the literature confirms the rationale of this approach in highly selected lesions.