A peculiar case of primary lymphoma of pancreas: A rare presentation of Hodgkin lymphoma

Primary pancreatic Hodgkin lymphoma (PPL) is an exceptionally rare condition often misdiagnosed as pancreatic adenocarcinoma or pseudocyst. Early histopathological diagnosis is crucial for prognosis and appropriate chemotherapy.

We report a case of a 50-year-old male presenting with low-grade fever, chills, abdominal pain, and 30-pound weight loss over 10 weeks. Examination revealed significant epigastric tenderness without icterus. Laboratory findings showed leukopenia (1.2K/UL), low absolute neutrophil count (238), hyperbilirubinemia, and elevated AST/ALT (185/165), with normal lipase and amylase. Imaging revealed a 4.7 × 5.1 × 6.6 cm solid heterogeneous pancreatic head mass with multiple prominent retroperitoneal, gastro-hepatic, para-aortic, and portacaval lymph nodes. Retroperitoneal lymph node biopsy confirmed nodular sclerosis Hodgkin lymphoma with positive CD15, CD30, MUM-1, and EBV stains. Bone marrow biopsy revealed lymphoma infiltration, prompting initiation of A+AVD (brentuximab vedotin, doxorubicin, vinblastine, dacarbazine) chemotherapy for stage IV disease based on Karnofsky Performance Status.

Hodgkin lymphoma, a malignant B-cell neoplasm, constitutes 11% of lymphomas and is characterized by Reed-Sternberg cells. PPL is extremely rare, often mimicking pancreatic adenocarcinoma. Features such as absent pancreatic atrophy, tumor necrosis, calcification, and vascular invasion may aid differentiation. Treatment depends on disease stage, with early stage managed by ABVD (Adriamycin, Bleomycin sulfate, Vinblastine sulfate, Dacarbazine) chemotherapy and radiation, while advanced cases require extended A+AVD chemotherapy. PPL accounts for <2% of extra-nodal lymphomas but remains a potentially treatable entity. This case underscores the importance of obtaining tissue diagnosis in the setting of a pancreatic mass before embarking on definitive treatment.