True histiocytic lymphoma.

True histiocytic lymphomas are very rare tumors that show histiocytic differentiation and express histiocytic markers in the absence of B-cell or T-cell lineage-specific immunologic markers.

Kamel OW, Gocke CD, Kell DL, et al.: True histiocytic lymphoma: a study of 12 cases based on current definition.

Soslow RA, Davis RE, Warnke RA, et al.: True histiocytic lymphoma following therapy for lymphoblastic neoplasms.