Imprint cytology of large B-cell lymphoma with high content of epithelioid cells. A report of two cases.

An association of epithelioid cell reaction in follicular center cell lymphomas seems to be a rare phenomenon. The cytological features of this type of B-cell lymphoma from two patients are presented. In both cases, immunohistochemistry applied to paraffin sections revealed reactivity of tumor cells for CD10, 20 and 79a. The first patient, a 77-year-old male, presented with bilateral inguinal bulky masses. The second patient, a 76-year-old female, revealed left supraclavicular bulky masses. Imprint cytological specimens of these two cases showed large lymphoid cells interspersed with epithelioid histiocytes, which were present in small aggregated clusters or in isolated forms. Most tumor cells showed centroblastic morphology, whereas the minority of them looked like immunoblasts. Occasionally, a monotonous proliferation of these large atypical blastic cells was also detected. On the other hand, in some parts of the imprint specimens, numerous epithelioid cells obscured the underlining tumor cells. Reactive cells other than epithelioid cells were not prominent. These cytologic features closely resembled the histologic patterns of this rare follicular center cell lymphoma. Careful examination of the cytological specimens is needed to detect the monotonous proliferation of tumor cells to establish the diagnosis of malignant lymphoma.