Composite lymphoma

Abstract

Composite lymphomas (CL), comprising two distinctly different and well-delineated varieties of lymphoma occurring in a single anatomic site or mass, are unusual. This series represents an analysis of 20 patients with such lesions. There were 13 men and 7 women, and the patients' ages varied from 31 to 85 years. In 12 patients, the composite lymphomas consisted of different types of non-Hodgkin's lymphomas, whereas a combination of Hodgkin's disease and non-Hodgkin's lymphoma was observed in the remainder. The most frequent combination (7/20) was that of diffuse histiocytic lymphoma (DH) and nodular, poorly differentiated lymphocytic lymphoma (NLPD), according to the criteria of Rappaport. The composite pattern was present in lymph nodes in 12 patients, spleen in three, retroperitoneum in one, liver in two, and both spleen and lymph nodes in two patients. In 13 patients in whom NLPD was one histologic component, the identical histology was reflected in additional lesions distant from the composite site, in 10. The belated discovery of a composite pattern in one patient emphasized the need for a thorough examination of all the material available when one encounters two different histologic types of lymphoma in different sites. Of 11 patients who died, eight had DH as one component, and in seven of these, death occurred within 20 months after the diagnosis of a composite lymphoma. Clearly, prognosis relates to the recognizably more aggressive component. Nevertheless, recognition of CL at one site is important to account for varying histologic features in widely disseminated lesions.