Primary lymphomas of the cranial vault are most unusual lesions. Only six cases have been described in the literature. We report a case of a 71 year old female who was admitted with an occipital mass. A C.T. scan revealed a mainly extra cranial tumor with an osteolysis of the cranial vault and a small intracranial component. It was diagnosed as a phenotype B centroblastic lymphoma. Half of the patients reported in the literature had a subcutaneous mass as the main symptom. These neoplasms are usually highly malignant tumors. The treatment realized is neurosurgical excision followed by chemotherapy and radiotherapy.