Primary cranial vault non-Hodgkin’s lymphoma

S Mongia, D Shukla, B Indira Devi, TV Reddy 
 Department of Neurosurgery National Institute of Mental Health and Neuro Sciences Bangalore-560029, India

Correspondence Address:
B Indira Devi
Department of Neurosurgery National Institute of Mental Health and Neuro Sciences Bangalore-560029
India

Full Text

Sir,

Primary cerebral non-Hodgkin's lymphomas are a rare group of neoplasms. They are mostly intraaxial. Invasion of pachy and leptomeninges is frequent,[1] however, primary malignant lymphoma arising within the skull vault or scalp without involvement of the cerebral parenchyma, systemic or skeletal manifestation, is rare. Sporadic cases have been reported in the literature.[2],[3],[4]

A 25-year-old man presented with a history of progressively increasing scalp swelling and local pain over the past 6 months. On examination, a 10 x 15 cm large scalp swelling was present in the right fronto-temporo parietal region. The scalp swelling was non-compressible and of variable consistency.

X-ray examination showed no bony erosion. CT scan showed scalp swelling. There was no intracranial abnormality. A near total excision of the right fronto-temporo parietal swelling was performed. Histology revealed non-Hodgkin's lymphoma. Ultrasonography of the abdomen, peripheral smear and bone marrow examination were negative for lymphoma. Postoperatively, he received radiotherapy along with adjuvant chemotherapy.

Bony involvement is commonly seen with secondary non-Hodgkin's lymphoma including that of the scalp[1]. However, non-Hodgkin's lymphoma originating primarily in the bones is seen in only about 3-4% of patients. The most common bone involvement is seen in the femur or pelvis (50%), humerus (20%) with the remaining 30% occurring in the spine, ribs, mandible and scapula.[2],[3]

Primary lymphoma of the skull vault is extremely rare.[1] A true primary malignant lymphoma of the bone is defined as “a solitary mass lesion with no evidence of disease at other sites and no systemic dissemination within 6 months of the detection of tumor”.[5] Our patient did not show any evidence of disease at other sites, there was no systemic dissemination even after 2-and-a-half years following the detection of the tumor at the vault / scalp.

In some cases plain X-ray of the skull may not show the destruction of the bone, as malignant lymphoma often has a permeative growth pattern with a soft tissue compartment and very little cortical destruction.[2] This finding was seen in our case. Pathologically, the spread of the disease to the meninges suggests that the lymphoma cells grow through the diploic spaces along the emissary veins and nerves that pass through the dura to the leptomeninges.[2] Our patient did not have any intracranial spread.

Lymphomas of the cranial vault usually involve the pericranium, underlying meninges and subcutaneous tissues. These lesions are effectively treatable by surgery and radiotherapy with a good outcome in most cases.[2],[3] A high index of clinical suspicion, awareness of the characteristic CT features and aggressive therapy are therefore required. Although this condition is rare, the diagnosis must be considered in the differential diagnosis, in any patient with a scalp mass extending through the skull. The prognosis of a lymphoma appearing in the skull vault is uncertain, but any involvement of the cerebral structures by direct invasion or by leptomeningeal seeding should indicate a less favorable prognosis.

References