gms | German Medical Science

Objective: Meningeoma is the most common dural neoplasm. However, a variety of tumor entities may present clinically as meningeoma. Even though a significant number of patients with solitary plasmacytoma, will eventually develop multiple myeloma, intracranial plasmacytoma is exceptional and has been very rarely described as primary manifestation of multiple myeloma.

Methods: Case 1: A 61 year old man presented with a protrusion occipitally on the left side of his head. Cranial MRI showed a lesion suggestive of intraosseous meningioma. Based on typical findings, a neuropathological diagnosis of plasmacytoma was established. This diagnosis prompted complete skeletal radiographs, which revealed an osteolytic lesion of the eighth rib. Bone marrow cytology also revealed neoplastic plasma cells. Case 2: In this 52 year old patient with a progressive occipital mass a MRI supposed a highly vascularized meningioma with compression of the sagittal and transversus sinus. An interventional embolization was conducted preoperatively. Neuropathological examination demonstrated a plasmacytoma.

Results: Intracranial plasmacytomas are rare and infrequently diagnosed by imaging due to their resemblance of meningiomas. On MRI, plasmacytomas are often indistinguishable from meningioma, with intermediate signal on T -weighted sequences and isointense signal to gray matter on proton density and T2-weighted sequences. With contrast, they frequently demonstrate homogenous enhancement, similar to our two cases. The tumors showed the typical histological and immunohistochemical staining profile of plasmacytoma. Since additionally CD20-expressing lymphocytic tumor cells were also encountered in case 1, a diagnosis of “lymphocytic plasmacytoma” was established, which is very rare and may be associated with IgA-heavy chain restriction.

Conclusion: In conclusion, solitary intramedullary plasmacytoma should be considered in the differential diagnosis of meningioma in dural based neoplasms. Vice versa in dural based plasmacytoma lymphocyte rich meningioma must also be considered as a differential diagnosis. In some cases differentiation may be difficult.