SECONDARY PANCREATIC DIFFUSE LARGE B-CELL LYMPHOMA: AN EUS DIAGNOSIS OF A RARE CAUSE OF PANCREATIC MASS

Aims:

Pancreatic lymphomatous involvement is an unusual event: primary pancreatic lymphoma represents a rarity, accounting for less than 2% of all lymphomas. Secondary pancreatic involvement can occur but cytological diagnosis is very rarely performed considering the multiorgan dissemination. Pancreatic involvement may be misdiagnosed as pancreatic cancer thus leading to incorrect therapeutic management. the Endoscopic Ultrasound (EUS) has emerged as the most cost-effective and safe procedure to obtain the diagnosis of pancreatic lesions. we report an unusual case of secondary, pancreatic, nodular involvement diagnosed by EUS guided fine needle aspiration (FNA) in patient suffering from a diffuse large B-cell lymphoma.

Methods:

An asymptomatic 68-ys-old male patient was referred to our hospital for lymphoma follow-up. A Ct scan showed a doubtful enlargement of the pancreatic head. An Eus was performed showing a hypoechoic mass measuring 17 mm in diameter, with infiltrative margins, a central area of necrosis and ipoenhancement on evaluation using ev mdc (Sonovue). An FNA (3 passes, 25 G needle and 3 passes, 22 G) in order to confirm or rule out pancreatic involvement by the known lymphoproliferative disease

Results:

Both the direct smears and the cell block sections displayed an abundant, scattered population composed by monomorphous large cells with round nuclei, with multiple nucleoli acting as lymphoid centroblasts. The immunocytochemistry analysis confirmed the cytological hypothesis showing expression of CD20 and CD79a and negativity for CD3 and cytokeratin AE1/AE3.

Conclusions:

Pancreatic malignant lymphomas are unusual, solid tumors categorized as non-epitehelial neoplasms. Primary pancreatic lymphoma is an extremely rare entity but secondary pancreatic involvement can occur in up to 30% of patients. EUS-FNA is a safe, concrete tool to achieve pancreatic involvement in this setting of lymphomatous diseases and it's fundamental for the therapeutic patient management. Moreover an important role is played by the cytopathologist's expertise for an accurate diagnosis with ancillary techniques in deceiving cases