Severe Headache and Deterioration of Vision in Left Eye in a Chronic Hemodialysis Patient Revealing a Brown Tumor of Sphenoid Sinus.

Background/objectives: Brown tumors are rare bone lesions associated with hyperparathyroidism, particularly secondary hyperparathyroidism (SHPT), in chronic renal failure. While brown tumors commonly affect bones rich in marrow, the involvement of the sphenoid sinus is extremely rare and can present with neurological symptoms. This study reports a case of a sphenoid sinus brown tumor in a patient on hemodialysis, highlighting its clinical presentation and diagnostic challenges.

Methods: A 31-year-old woman undergoing chronic hemodialysis presented with a severe headache, diplopia, and progressive vision loss in her left eye. Laboratory tests revealed hypercalcemia, hypophosphatemia, and elevated parathyroid hormone (PTH) levels, consistent with SHPT. The diagnosis was confirmed through a clinical examination and magnetic resonance imaging (MRI).

Results: The clinical examination confirmed decreased visual acuity in the left eye. The laboratory results revealed serum calcium of 15.5 mg/dL, phosphate of 1.0 mg/dL, and PTH of 2000 pg/mL, consistent with SHPT. The imaging studies identified a brown tumor in the sphenoid sinus exerting a mass effect on adjacent structures. This case underscores the rarity of brown tumors in this location, with very few similar reports in the literature.

Conclusions: Although rare, brown tumors should be considered in patients with SHPT who present with neurological symptoms or cranial lesions. An early diagnosis through biochemical and imaging studies is crucial to prevent severe complications. The management involves treating the underlying hyperparathyroidism, with surgical intervention indicated in cases of neural compression.