Operative diagnosis of a meningioma-like intraosseous skull lesion revealing multiple myeloma: Case report and literature review.

BACKGROUND: Multiple myeloma (MM) is a hematologic malignancy characterized by abnormal proliferation of clonal plasma cells. Skull involvement is common in MM, typically presenting as small "punched-out" lytic lesions; however, large destructive calvarial masses are uncommon and can radiologically mimic other skull tumors such as meningiomas, hemangiopericytomas, or metastatic disease, making tissue diagnosis essential. This report presents a case of MM initially misdiagnosed as an intraosseous meningioma, highlighting the diagnostic challenges of destructive calvarial lesions and the value of preoperative embolization in managing hypervascular skull tumors.

CASE DESCRIPTION: A 48-year-old male with no prior medical history presented with a progressively enlarging left parietal scalp swelling, headaches, dizziness, and left-sided numbness. Brain magnetic resonance imaging revealed an 8.4 × 5.1 × 4.5 cm destructive skull lesion with intracranial and extracranial components. Given the radiological findings, the differential diagnosis included intraosseous meningioma, atypical meningioma, or metastatic bone disease. The patient underwent preoperative embolization to reduce intraoperative bleeding, followed by a left frontoparietal craniectomy and complete tumor resection. Histopathological analysis confirmed MM, prompting hematology consultation and systemic evaluation. The patient recovered well postoperatively, with plans for cranioplasty.

CONCLUSION: MM should remain on the differential diagnosis for any destructive calvarial lesion, regardless of size. Early tissue diagnosis and a multidisciplinary approach involving neurosurgery, hematology, and radiation oncology are essential for optimal management.