Pancreatic Fistula Extending into the Thigh Caused by the Rupture of an Intraductal Papillary Mucinous Adenoma of the Pancreas

Main-Duct Intraductal Papillary Mucinous Neoplasm Complicated by a Pancreaticogastric Fistula and a Pancreaticocholedocal Fistula

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are a spectrum of benign to malignant epithelial neoplasms that are characterized by papillary proliferation, duct dilation, and cyst formation. A rare complication of IPMNs is fistula formation into adjacent organs such as the duodenum, biliary system, and stomach. Here, we report a case of IPMN with a pancreaticobiliary fistula and pancreaticogastric fistula. An 84-year-old woman with early Alzheimer's disease was diagnosed with IPMN of the pancreas. She deferred surgery given her age and remained asymptomatic for five years until presenting with cholangitis. She had been further evaluated and was found to have a pancreaticobiliary fistula, which was treated with biliary stent placement. Her subsequent admission involved the formation of a new pancreaticogastric fistula. This case highlights potential complications of excess mucin production from unresected IPMNs and demonstrates a guarded prognosis in elderly patients.

A Case of Pancreatic Duct Leak Presenting as Lower Extremity Pain and Edema

Pancreatic pseudocyst from pancreatic duct leak is one of the common complications of both acute and chronic pancreatitis. The presentation of such leaks can range from patients being completely asymptomatic to septic shock. Extra-abdominal collections of fluid due to pancreatic duct leaks are very rare. We describe a diagnostically challenging patient with acute chronic pancreatitis presenting with lower extremity swelling and pain, who was found to have a pancreatic fluid leak into the right iliopsoas, right gluteal, and thigh muscle compartment. Despite endoscopic stenting of the pancreatic duct and multiple percutaneous drain placement and antibiotic treatment for abscess formation, the patient's condition deteriorated clinically. Surgical options could not be pursued due to poor functional status.

A Rare Case of Intraductal Tubulopapillary Neoplasm of the Pancreas Rupturing and Causing Acute Peritonitis

An intraductal tubulopapillary neoplasm (ITPN) is a very rare pancreatic tumor. Here we report an extremely rare case of an ITPN rupturing and causing acute peritonitis. A 50-year-old woman presented with left flank pain and vomiting. A computed tomography (CT) scan revealed gigantic multilocular cysts in the pancreatic tail and massive fluid collection in the abdominal cavity. The serum, urine, and abdominal fluid amylase levels were highly elevated, so she was conservatively treated with intraperitoneal drainage and antibiotics for a diagnosis of ruptured pancreatic cysts. After this patient recovered, a CT scan revealed a 2-cm low-density mass located in the body of the pancreas. This was diagnosed as a pancreatic ductal adenocarcinoma of the pancreatic body with an intraductal papillary mucinous neoplasm, and a distal pancreatectomy was performed. The tumor was composed of cuboidal high-grade dysplastic cells proliferating in a tubulopapillary growth pattern without mucin production. An immunohistochemical examination revealed that the tumor cells were positive for MUC1 and CK7, but negative for MUC5AC. These features led to the final diagnosis of ITPN. In this case, the solid ITPN growth obstructed the lumen of the main pancreatic duct, and the intraductal pressure of the distal side rose gradually. Then, pancreatic cysts formed and burst into the abdominal cavity when the intraductal pressure was at its maximum. However, an ITPN consists of high-grade atypical cells derived from the pancreatic ductal epithelium in principle, so the rupture may be an independent risk factor for peritonitis carcinomatosa in the future.

Rupture of small cystic pancreatic neuroendocrine tumor with many microtumors

Pancreatic neuroendocrine tumors (pNETs) are particularly rare. The various forms of PNETs, such as cystic degeneration, make differentiation from other similar pancreatic lesions difficult. We can detect small lesions by endoscopic ultrasound (EUS) and obtain preoperative pathological diagnosis by EUS-guided fine needle aspiration (FNA). We describe, here, an interesting case of pNET in a 42-year-old woman with no family history. Computed tomography and magnetic resonance imaging revealed an 18 mm × 17 mm cystic lesion with a nodule in the pancreatic tail. Two microtumors about 7 mm in diameter in the pancreatic body detected only by EUS, cystic rim and nodules all showed similar enhancement on contrast-harmonic EUS. Preoperative EUS-FNA of the microtumor was performed, diagnosing multiple pNETs. Macroscopic examination of the resected pancreatic body and tail showed that the cystic lesion had morphologically changed to a 13-mm main nodule, and 11 new microtumors (diameter 1-3 mm). Microscopically, all microtumors represented pNETs. From the findings of a broken peripheral rim on the main lesion with fibrosis, rupture of the cystic pNET was suspected. Postoperatively, pituitary adenoma and parathyroid adenoma were detected. The final diagnosis was multiple grade 1 pNETs with multiple endocrine neoplasia type 1. To the best of our knowledge, no case of spontaneous rupture of a cystic pNET has previously been reported in the English literature. Therefore, this case of very rare pNET with various morphological changes is reported.