Primary pancreatic lymphoma: diagnostic pitfall of an uncommon medical entity mimicking operable pancreatic carcinoma: case report and review of literature

Almost all pancreatic neoplasms, including the commonest pancreatic ductal adenocarcinoma (PDAC) are derived from pancreatic epithelial components. Primary pancreatic lymphoma (PPL) is rare, accounting for less than 0.5% of all primary pancreatic tumours and presents a diagnostic and therapeutic challenge owing to their rarity, difficult access, and clinical and imaging features, which can mimic PDAC. A 26-year-old man presented with pain abdomen, jaundice, anorexia and weight loss for two months, along with two episodes of hematemesis and melena. Examination revealed an icteric patient with no palpable abdominal lump. His had a serum bilirubin of 13.6 mg/dl. His ultrasound abdomen, CT scan and MRCP showed a mass in the head and uncinate process of the pancreas with circumferential nodular thickening in second part of duodenum. Side viewing endoscopy was suggestive of carcinoma head of pancreas with duodenal infiltration, for which endoscopic biopsy was taken which revealed non-Hodgkin's lymphoma B cell type. A PET CT showed a metabolically active mass lesion in the head of pancreas, with no other focus of disease anywhere else, suggestive of primary pancreatic lymphoma. This patient was referred to Medical oncology and started on chemotherapy. Lymphoma should be considered when a large, homogeneous, hypoenhancing mass is encountered in the pancreatic head, and with bulky lymphadenopathy. Preoperative tissue diagnosis such as fine needle aspiration cytology with or without flow cytometry and/or laparoscopy/endoscopy guided tissue biopsy may be necessary. It is crucial to differentiate PPL from pancreatic adenocarcinoma since their treatment is primarily medical and prognosis differs considerably.

PRIMARY PANCREATIC LYMPHOMA WITH HERPES ZOSTER ASSOCIATED ACUTE PANCREATITIS: A CASE REPORT AND REVIEW OF LITERATURE.

Primary pancreatic lymphoma (PPL) is an extremely rare disease, with few cases reported in literature. Clinical manifestations are usually nonspecific and mimic other pancreatic diseases. Owing to paucity of data and experience of PPL, clinico-pathological features, differential diagnosis, optimal treatment and overall outcomes are not well known. Varicella zoster virus (VZV) is known to cause varicella in children and herpes zoster in adults. Acute pancreatitis caused by VZV is a rare and serious complication, with immunocompromised individuals being primarily affected. We report a case of VZV associated acute pancreatitis in a patient who was diagnosed and treated for primary pancreatic lymphoma, thus rendering her immunocompromised and susceptible to developing infectious pancreatitis. A 56 year old female patient presented with recurrent vomiting, upper abdominal pain and hyperaesthesia in the right upper quadrant of 2 days duration. Following admission her right sided abdominal pain worsened (stabbing pain) and a diagnosis of acute pancreatitis was confirmed based on elevated serum amylase levels and CT scan findings of pancreatic enlargement. The patient was managed conservatively with intravenous fluids, antibiotics, analgesics and topical acyclovir ointment. The patient continues to be asymptomatic after 5 years of follow up. Though extremely rare, a diagnosis of herpes zoster pancreatitis should be considered in such patients, and prompt treatment initiated to prevent further deterioration and to minimize mortality. Core tip: Primary pancreatic lymphoma is in itself a very rare disease, and our patient having presented with herpes zoster associated acute pancreatitis in a background of PPL makes this case even rarer. This is probably the first case report of herpes zoster associated acute pancreatitis in an immunocompromised patient due to primary pancreatic lymphoma.

Primary Pancreatic Lymphoma Masquerading as Carcinoma

Adenocarcinoma is the most common primary pancreatic neoplasm type, followed by secondary pancreatic lymphoma and primary pancreatic lymphoma (PPL). PPL is associated with peripancreatic lymphadenopathy and usually presents as a homogenous mass with extrapancreatic invasion into surrounding structures. However, localized involvement of the distal pancreas is uncommon, and diffuse involvement of the pancreas is even rarer. Herein, we present the case of a 53-year-old woman with PPL of the uncinate process with biliary obstruction mimicking pancreatic adenocarcinoma, successfully diagnosed nonoperatively. Abdominal computed tomography showed an ill-defined uncinate process mass, hypodense with mild enhancement (3.9×3.4×3.5 cm), infiltrating the second and third parts of the duodenum. Biopsy revealed NHL with no evidence of adenocarcinoma. PPL was diagnosed. She received chemotherapy with a CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) protocol with rituximab, which she tolerated with no clinical or radiological evidence of recurrence at 1-year follow-up.