Primary B‐cell malignant lymphoma of the maxilla with a sarcomatous pattern and multilobated nuclei

Three cases of primary malignant lymphoma of the maxilla are reported. The primary intraosseous origin of these tumors was demonstrated by x‐ray examination and surgical exploration. The initial interpretation as odontogenic infection led to a delay in starting therapy of 9 months in one case. Biopsies of two cases were initially interpreted as sarcoma because of a dense reactive fibrosis between the tumor cells. Subsequently, hemimaxillectomy was performed in one case. Histologically and ultrastructurally the tumor cells showed marked nuclear abnormalities with cleavage, folding, and lobulation. Immune histochemical studies of two cases showed a monoclonal immunoglobulin expression, IgG‐K; T‐lymphocyte‐associated antigens were not detected on the tumor cells. The findings indicate the existence of a primary B‐cell malignant lymphoma of bone with multilobated nuclei. The lymphoid nature may be masked by a dense proliferation of connective tissue. The relation of these tumors to the classifications for malignant lymphoma of lymph node is discussed.