"Imaging features of extramedullary plasmacytoma of skull base with multiple myeloma"- a rare case

Sphenoid plasmacytoma as initial presentation of multiple myeloma-case report

Plasmacytoma is a rare plasma cell neoplasm. Whether solitary or associated with multiple myeloma (MM), it rarely involves the skull base, particularly the sphenoid bone. We present a unique case of sphenoid bone plasmacytoma secondary to MM, highlighting diagnostic and therapeutic challenges. A 56-year-old female presented with headaches, vomiting, epistaxis, and cranial nerve deficits. Cerebral imaging revealed a 65-mm tumor infiltrating the sphenoid bone and adjacent structures. Subtotal resection was performed using an endoscopic nasal approach. Histopathology revealed plasmacytoma, and diagnostic workup confirmed MM. By the end of biological exploration, relapse of the sphenoid plasmacytoma was observed, and the patient was successfully treated with radiotherapy, immunochemotherapy, and autologous stem cell transplantation. After 18-month follow-up, sustained complete remission was confirmed. Although rare, the diagnosis of plasmacytoma should be considered in cases of skull base tumors. This localization is highly predictive of MM, warranting comprehensive investigations to initiate prompt and adequate management.

Cerebral Venous Thrombosis with Papilloedema Secondary to Skull Base Plasmacytoma

A 60-year-old woman with history of multiple myeloma was in remission after stem cell transplant 6 years prior. She was undergoing work-up for headaches that were thought to be secondary to a right mastoiditis seen on magnetic resonance imaging (MRI). On routine eye exam, papilloedema was noted. A lumbar puncture was performed, with elevated opening pressure with normal constituents. She was an atypical age for idiopathic intracranial hypertension, and her mastoiditis raised concern for secondary cerebral venous sinus thrombosis. Magnetic resonance venography (MRV) was performed showing poor flow in the right sigmoid sinus, and computed tomography venography (CTV) showed lack of contrast enhancement distal to the right sigmoid sinus, consistent with occlusion. There was also an enhancing mass inferior to the right occipital bone. Biopsy confirmed recurrent plasma cell myeloma. She was treated with chemotherapy, radiation, and warfarin for presumed cerebral venous sinus thrombosis.