Multiple myeloma mimicking olfactory sulcus meningioma: Case report and literature review.

Central nervous system involvement by multiple myeloma is extremely rare and is diagnosed in less than 1% of cases. Differential diagnosis includes lymphomas, metastases, sarcomas, osteochondromas, hemangiopericytomas or meningiomas. We report a 46-year-old female with a history of multiple myeloma in apparent remission after autologous bone marrow transplantation, who consulted for a palpable mass in the frontal region associated with holocranial headache and decreased visual acuity of two months of evolution with imaging studies compatible with olfactory sulcus meningioma. A craniotomy and total resection of the lesion by bicoronal approach was performed and histological sections showed a neoplastic proliferation consisting of cells with a spherical nucleus and lateralized eosinophilic cytoplasm. Lesion compatible with involvement of the central nervous system by multiple myeloma. This case highlights the diagnostic challenge due to radiologic similarity with other tumours, especially meningiomas, and emphasizes including myeloma in differential diagnoses.