Mantle Cell Lymphoma with Mantle Zone Pattern

Lesson From the Friday Unknowns

Histologic sections show needle shaped fragments of lymph node focally involved by lymphoma. The neoplasm is located predominantly in the mantle zone of lymphoid follicles with hyperplastic germinal centers. The mantle zone is slightly expanded in some of those lymphoid follicles. The tumor cells are small to intermediate in size.

Immunohistochemical studies show that the tumor cells are positive for CD20, CD5 (subset) and cyclin D1 and negative for CD3. Ki-67 shows a…