Bone marrow involvement in malignant lymphoma without peripheral lymphadenopathy.

Twelve cases of non-Hodgkin's lymphoma and a single case of Hodgkin's disease were first diagnosed on bone marrow biopsy. None of the patients had superficially enlarged lymph nodes, and in 3 patients the histological examination of the biopsy specimen showed normal reactive nodes. Eight patients were over the age of 60. The differential diagnosis from benign nodular lymphoid hyperplasia is discussed, with emphasis on the cytology and the paratrabecular position of the lymphoid infiltrate. Ten patients had focal involvement of the bone marrow and 1 of the 3 patients with diffuse involvement had Hodgkin's disease. Lymphoid nodules occur normally in the bone marrow and we conclude that non-Hodgkin's lymphoma and Hodgkins's disease can arise primarily in the bone marrow.