Malignant histiocytosis and large cell anaplastic (Ki-1) lymphoma in childhood: guidelines for differential diagnosis--report of the Histiocyte Society.

A workshop of the Histiocyte Society was recently held, in order to discuss the problems and confusion of malignant histiocytosis (MH) and large cell anaplastic (Ki-1) lymphoma (LCAL). The aims of this workshop were to clarify the terminology for malignant histiocytic disorders and LCAL and to produce reliable criteria for diagnosis of both MH and LCAL. This article summarises the conclusions reached.