The authors report two patients who presented with a mass in their thigh muscles. On the basis of the histologic appearance, a diagnosis of small cell malignancy was made. Further investigations including electron microscopy and immunoperoxidase techniques were necessary to accurately identify these tumors as lymphoma. Intramuscular lymphoma is rare, but it should be considered in the differential diagnosis, when the tumor consists of small cells. Special techniques are mandatory for a definitive diagnosis.