A Case of Malignant Lymphoma Misdiagnosed as Focal Lymphoid Hyperplasia in the Esophagus

Chung, Sook Keum; Ko, Young Hyeh; Park, Chan Keum; Lee, Jung Dal

Abstract

Esophageal involvement by malignant lymphoma is extremely rare. A case of follicular lymphoma of the esophagus, misdiagnosed as focal lymphoid hyperplasia (pseudolymphoma) in a 72-year-old man is presented. The esophagogram revealed diffuse narrowing of the lumen in the middle and distal portion without ulceration. The resected esophagus showed mural thickening without any remarkable mucosal change. Microscopically, the esophagus showed scattered follicular lymphoid aggregates in the submucosa, extending into periadventitial fat tissue. Most follicles were devoid of germinal center and consisted of loosely aggregated small cleaved cells without atypia. The surrounding stroma of the submucosa showed dense fibrosis entrapping the infiltrating small lymphocytes in a "indian-file" appearance. There were some reactive follicles with germinal center. In the lamina propria, many plasma cells and a few eosinophils were infiltrated. The gene rearrangement study showed rearranged band for Jk probe which confirmed monoclonal B-cell nature of infiltrated small lymphoid cells. The small cleaved lymphocytes arranged in follicles were positive for L26 and bcl-2 protein. This case demonstrated the necessity of immunophenotypic and gene rearrangement study in the diagnosis of pseudolymphoma in the digestive tract.