Cytodiagnosis of a primary non-Hodgkin's lymphoma of bone.

We report fine-needle aspiration cytology and histologic findings of a primary non-Hodgkin's lymphoma of bone involving the rib and iliac bones. Smears contained abnormal lymphoid cells and abundant lymphoglandular bodies, suggesting a malignant lymphoproliferative disease. However, histologic sections showed nests of tumor cells with extensive cytoplasmic clearing surrounded by sclerosis, thus mimicking a carcinoma. Clinical data, radiographic findings, and cytohistological correlation led to a final diagnosis of primary non-Hodgkin's lymphoma of the bone, confirmed by immunopositive staining for leukocyte common antigen CD45 and B-cell associated antigen CD20. It is concluded that finding numerous lymphoglandular bodies in bone tumor specimens allows an accurate diagnosis of lymphoid tissue. The rarity of bone lymphoma and the misleading histologic features can cause considerable difficulty in diagnosing this entity. The importance of identifying lymphoglandular bodies and the appropriate use of immunochemistry are emphasized.