Dural Plasmacytoma with Meningeal Myelomatosis in a Patient with Multiple Myeloma

A Rare Case of Epidural Myeloma Presenting as Recurrent Subdural Bleeding

Multiple myeloma (MM) is an incurable clonal B-cell malignancy that usually presents with neoplastic monoclonal plasma cells in either bone or soft tissues. Central nervous system involvement of the myeloma (CNS-MM), such as dural myeloma or intraparenchymal infiltration, or diffuse leptomeningeal involvement, is uncommon. Dural involvement of myeloma without parenchymal or leptomeningeal disease is even rarer, with only seven cases reported previously. We present a case of epidural myeloma in a 50-year-old man with known kappa light chain MM, presenting with multiple episodes of subdural hemorrhage and progressive neurological deficits. He initially presented with severe back pain, hypercalcemia, and acute kidney injury (AKI). Further evaluation showed lytic bone lesions and elevated kappa light chains, and bone marrow biopsy showed 32% of clonal plasma cells. He was initially treated with bortezomib, lenalidomide, and dexamethasone combination, followed by pomalidomide and daratumumab. Eventually, he developed two episodes of subdural hemorrhage and left-sided seventh cranial nerve palsy, which was treated conservatively and monitored by computed tomography (CT) of the head. However, he gradually developed multiple cranial nerve palsies, weakness, and urinary incontinence. Cerebrospinal fluid (CSF) analysis showed elevated protein without any aberrant immunophenotype. Magnetic resonance imaging (MRI) of the brain showed diffuse smooth dural enhancement with extensive calvarial and skull base marrow replacement; MRI of the spine showed diffuse epidural enhancement in thoracic and lumbar regions, findings consistent with epidural myeloma. The patient received three doses of cranial irradiation but, unfortunately, could not tolerate further treatment and opted for hospice care. Intracranial hemorrhage is common in MM patients, and it is important to consider CNS involvement in patients presenting with recurrent subdural hemorrhage and to perform imaging (preferably MRI) earlier in the disease course. Due to its rarity, the treatment of CNS-MM is very heterogeneous. Thus, case reporting is important to accumulate data on this rare presentation.

Solitary Plasmacytoma with Amyloid - An Unusual Dural-Based Lesion

Solitary plasmacytoma of the dura without systemic involvement are extremely rare lesions, with <15 cases reported in the literature. Among these, ours is the second case to show the presence of amyloid. Fifty-year-old male had presented with headache, sudden onset right-sided weakness, and vomiting. Magnetic resonance imaging revealed an extra-axial mass in the left fronto-parietal region measuring 10 cm × 8.7 cm × 3.9 cm, suggestive of meningioma. The left fronto-parietal craniotomy was performed and multiple tissue bits aggregating to 10 cm × 8.5 cm × 2 cm along with thinned out membrane-like bit of calvarium was sent for pathologic examination. H and E stained sections showed sheets of plasmacytoid cells along with amyloid, which showed apple-green birefringence on Congo red staining. On immunohistochemistry, tumor cells were positive for CD38, CD138, showed kappa light chain restriction and were negative for CD45, CD34. Hence, it was diagnosed as a plasma cell neoplasm. Further work-up with whole-body positron-emission tomography scan revealed no systemic involvement. Dural-based lesions can mimic meningioma radiographically as well as intraoperatively. Histopathological examination unveils the diagnosis, to guide appropriate therapeutic regimens.

Multiple myeloma with dural mater involvement

Multiple myeloma is an incurable clonal B-cell malignancy which may present with neoplastic monoclonal plasma cells in either bone or soft tissues. Central nervous system (CNS) involvement such as dural myeloma or intraparenchymal infiltration, or with diffuse leptomeningeal involvement, is uncommon. Dural involvement of myeloma without parenchymal or leptomeningeal disease is an even rarer occurrence; therefore there are no established treatment guidelines for CNS myelomatosis. Here we reported a refractory MM patient progressed to dura mater involvement after the induction therapy but showed good response to lenalidomide treatment.