Pancreatic lymphoma: A cytologic diagnosis challenge

Abstract

Very rarely lymphoma primarily or secondarily involves the pancreas. Involvement of the pancreatic parenchyma with lymphoma clinically may mimic pancreatic ductal adenocarcinoma (PDA) and other mass‐forming pancreatic lesions. Endoscopic ultrasound fine needle aspiration (EUS‐FNA) is the first step in the diagnostic pathway of managing these patients by providing a cytology specimen. Cytologically, lymphoma of pancreas can be misdiagnosed for a wide variety of pancreatic neoplastic and non‐neoplastic lesions. Cytological differential diagnosis includes well‐differentiated adenocarcinoma, acinar cell carcinoma, well differentiated neuroendocrine tumor, and autoimmune pancreatitis. Gastroenterologist's skills in providing adequate sample for preparing smears, cell blocks and/or performing flow cytometry, and also cytopathologist's skills in detecting atypical lymphocytic population are crucial factors. Although cytology examination has limitations to subclassify lymphoma, it plays a key role to redirect clinicians into the right patient‐care pathway. In this article, we present two cases of pancreatic lymphoma with emphasis on the discriminating cytomorphological features, and we also review literatures with reports of primary pancreatic lymphoma (PPL) to better understand the characteristics of this rare lesion.

The Value of Cellblock in Diagnosing Pancreatic Lymphomas

“…Few cases of plasma cell neoplasms, T-cell lymphomas, and Hodgkin lymphomas (HLs) have been reported [2, 11-14]. EUS-FNA is the first step in the correct diagnosis [1, 7]. Cytologically, lymphomas can be misdiagnosed for neoplastic and nonneoplastic pancreatic lesions [1, 4, 5].…”

“…EUS-FNA is the first step in the correct diagnosis [1, 7]. Cytologically, lymphomas can be misdiagnosed for neoplastic and nonneoplastic pancreatic lesions [1, 4, 5]. In such challenging cases, pancreatic EUS-FNA smears should be supplemented with FC or CB with a confirmatory IHC [13-15].…”

“…In such challenging cases, pancreatic EUS-FNA smears should be supplemented with FC or CB with a confirmatory IHC [13-15]. Cellular smears involved by high-grade lymphomas are readily recognizable as malignant, but may be confused with undifferentiated carcinomas, neuroendocrine tumors, acinar cell carcinoma, and particularly small-cell carcinoma [1, 5, 14]. De Las Casas et al [16] found that evenly distributed fine granular chromatin, paranuclear blue inclusions and nuclear fragments were statistically significant in differentiating small-cell carcinomas from lymphomas, while single tumor cells, lymphoglandular bodies, nuclear molding, crush artifacts, and cell clusters were less reliable.…”

“…The pancreas can be primarily or secondarily involved by various lymphoproliferative lesions [1-5]. Onsite endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a standard procedure to detect pancreatic tumors [6, 7].…”

“…Onsite endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is a standard procedure to detect pancreatic tumors [6, 7]. EUS-FNA smears can be helpful to diagnose lymphoid lesions, to detect relapses in known lymphoma cases, and to rule out carcinomas and pancreatitis [1-5]. Because the clinical and radiologic manifestations are not always specific, cytology has an important diagnostic role [4, 8].…”