Primary high-grade malignant lymphomas of bone.

Five cases of primary high-grade malignant lymphoma of bone are presented. The tumours occurred at a single site in all the cases and produced osteopathic lesions. Histologically, they were large cell tumours characterized by round to irregularly shaped nuclei with finely distributed heterochromatin and small to medium-sized nucleoli. The cytoplasm was moderate and slightly to moderately basophilic. In one case, giant cells similar to Hodgkin and Sternberg-Reed cells occurred. The tumour cells bore B-cell markers but did not express immunoglobulin. Three of the bone tumours were polymorphic centroblastic lymphomas. The remaining two cases were also high-grade malignant B-cell lymphomas which may also be derived from germinal center cells but this could not be further substantiated.