Objective: Immunoglobulin D multiple myeloma (IgD MM) is an uncommon type of MM characterized by an aggressive clinical behavior and a short survival time. We report a rare case in which oculomotor palsy caused by a sellar lesion was the initial manifestation of IgD MM; systemic treatments were beneficial in this case.
Clinical presentation: A 61-year-old man presented with diplopia, left-sided ptosis, and retro-orbital pain. An examination revealed left cranial nerve (CN) III and IV palsies. CT scanning demonstrated a mass in the sellar and parasellar regions and partial destruction of the left side of the dorsum sellae. MRI revealed that the mass extended into the left cavernous sinus with minimal suprasellar extension. An endocrinologic evaluation did not reveal any abnormality. At the time of admission, the patient had no symptoms of MM.
Intervention: A transsphenoidal resection was performed. Histopathologic examination revealed a tumor consisting of plasma cells. Appropriate laboratory studies, a bone scan, and a bone marrow biopsy led to a diagnosis of IgD lambda-type MM. High-dose chemotherapy followed by autologous peripheral blood stem cell transplantation was therapeutically beneficial. The patient's symptoms were gradually relieved.
Conclusion: This case demonstrates that an unusual sellar tumor might be the first manifestation of IgD MM. Careful observation can suggest a possible non-pituitary etiology for a tumor, leading to appropriate diagnostic and therapeutic procedures.