[Primary non-Hodgkin's lymphoma of the muscles]

On the basis of two personal observations and of 18 published cases, a review of primary non-Hodgkin lymphoma originating in the skeletal muscle is presented. The disease mainly affects persons in the seventh decade. Ninety-five percent of the tumors occur in the extremities, with 75% in the lower extremities. Most lymphomas were of low grade malignancy, with intermediate and high grade tumors accounting for 45% of cases. Reliable differentiation of NHL from other small round cell tumors of the soft tissues, such as rhabdomyosarcoma or Ewing sarcoma, and from metastatic carcinoma, is mandatory for therapeutic purposes. Diagnosis can be established by light microscopy alone in most patients. In doubtful cases immunohistochemistry may be required.