Simultaneous presentation of hairy cell leukemia and follicular small cleaved cell lymphoma in a patient with previous diagnosis of renal cell carcinoma.

Hairy cell leukemia is a lymphoproliferative disorder of the B lymphoid system that is associated with an increased incidence of second malignancies. Most of these second neoplasma have been solid tumours and few reports of lymphoid malignancies exist. We report here a case of simultaneous presentation of hairy cell leukemia diagnosed in the spleen of a patient under therapy for follicular lymphoma who had an antecedent history of renal cell carcinoma. The hairy cell leukemia and the follicular lymphoma were studied by means of molecular techniques and they were found to contain two different clonal B cell proliferations. This suggests an independent origin of these two B cell neoplasms. As far as we know, this is the first report of the coexistence of hairy cell leukemia and follicular lymphoma.