Combined endoscopic transorbital and transnasal approach for the management of a solitary plasmacytoma of the sphenoid bone: A case report and literature review.

Background: Parasellar plasmacytomas are rare neurosurgical entities. Intrinsic characteristics of these tumors, such as adjacent bone erosion and symptoms resulting from invasion and mass effect, may lead to the possibility of a solitary extramedullary plasmacytoma (SEP) as a differential diagnosis. Case Description: We present the case of a 39-year-old male with a 1-month history of bilateral decreased visual acuity, retroocular pulsating pain, and chromatic vision loss. A computed tomography scan of the head revealed a parasellar lesion causing chiasmatic compression, as well as clival, orbital, sphenoidal, and ethmoidal invasion. A combined transorbital and endonasal endoscopic approach was found suitable, and gross total resection was achieved. Histological analysis of the lesion established the diagnosis of a SEP. After radiotherapy, a new magnetic resonance imaging was performed, revealing a recurrence of the lesion with a high grade of invasion. The patient was treated with palliative radiotherapy, as surgical resection did not seem feasible. Conclusion: Surgical resection and radiotherapy may achieve remission of these lesions; however, recurrence rates remain high despite any treatment modality. Patients with this condition must be followed up with a multidisciplinary team due to the high risk of multiple myeloma progression.