S1470 Pruritis as the Presenting Symptom of Double Hit Pancreatic Lymphoma

Abstract

INTRODUCTION: Obstructive jaundice can be classified as either intraluminal, transmural, or extra luminal. Among extra luminal causes, mass effect from an underlying malignancy is often present. Most often this is the result of a primary pancreatic carcinoma. Rarely, obstruction of the bile duct can be caused by a lymphoma in the pancreatic region. When lymphoma is present, Non-Hodgkin’s Lymphoma (NHL) is most likely, with the most common subtype being diffuse large B-cell lymphoma (DLBCL). Double hit lymphoma (DHL) is an aggressive type of NHL characterized by rearrangements most commonly in the Myc gene and BCL 2 or 6 genes. CASE DESCRIPTION/METHODS: We describe a case of a 58 year old male with a history of hypertension, chronic kidney disease and heart failure, who was evaluated in clinic for a 2 week history of severe pruritis. Liver function tests revealed alkaline phosphatase 913 units per liter (U/L), AST 353 U/L, ALT 570 U/L and total bilirubin 2.32 mg/dL. The patient was admitted for further workup. CT abdomen revealed a 8 × 6 cm mass in the pancreatic head, concerning for primary pancreatic malignancy. He underwent endoscopic retrograde cholangiopancreatography with stent placement in the common bile duct and pancreatic duct as well as a biopsy of the mass. Biopsy revealed abnormal B cell populations consistent with lymphoma. Fluorescence in situ hybridization was performed and showed high grade B cell DHL with MYC gene rearrangement. Positron emission tomography (PET) scan was then performed showing hyper-metabolic matted adenopathy centered in the peripancreatic ligament distribution measuring up to 17.6 SUV, confirming lymphoma. Chemotherapy with rituximab, etoposide, prednisone, vincristine, cyclophosphamide and doxorubicin (R-EPOCH) was promptly initiated, as well as intrathecal prophylaxis with methotrexate. After completing 5 cycles, a repeat PET scan showed minimal metabolic activity at the known cancer site and no new or progressive findings. DISCUSSION: DHL presenting as pruritus in the setting of obstructive painless jaundice is a very rare entity. Due to the relative infrequency of this presentation, NHL is hardly considered in the initial differential diagnosis for obstructive jaundice. Overall, obstruction caused by lymphoma carries a more favorable prognosis than patients with obstruction from primary pancreatic malignancies. This case highlights the need for thorough evaluation of pruritus as early diagnosis of lymphoma can lead to better patient outcomes.Figure 1.: CT Abdomen with large pancreatic head mass.Figure 2.: Pre and Post Chemotherapy PET CT Scans. Left: Hypermetabolic matted adenopathy centered in the peripancreatic and gastrohepatic ligament distribution concerning for Lymphoma. Right: Stable matted lymphadenopathy in the peripancreatic region with stable generalized low-grade uptake. No new or progressive lymphomatous disease is seen.Figure 3.: Pancreatic Mass Biopsy Histology, PAP stain at 40X. Red arrow - large cells 2-5x the size of a small lymphocyte. Black arrow - lymphocyte with nucleus as large as a histiocyte nucleus.