An unexpected case of frontal headache: Silent corticotroph pituitary neuroendocrine tumor presenting as a sphenoid sinus mass.

We report the case of a 43-year-old male who presented with a 2-year history of frequent frontal headaches, initially attributed to sinus disease. Magnetic resonance imaging revealed a 30 mm mass in the right sphenoid sinus with extension into the cavernous sinus, encasing the internal carotid artery, and invading the sella turcica. Differential diagnosis based on imaging included sphenoid meningioma, low-grade carcinoma, or lymphoma. An endoscopic sphenoid sinus biopsy identified the lesion as a silent corticotroph pituitary neuroendocrine tumor/adenoma (SCA), confirmed by positive immunostaining for ACTH and T-PIT. The patient underwent a successful transsphenoidal resection, followed by a transient postoperative central adrenal insufficiency and diabetes insipidus, which resolved within eight months. Eighteen months postoperatively, the patient retains normal pituitary function with minimal residual tumor. This case illustrates the diagnostic challenge posed by SCAs when presenting as sphenoid sinus masses and highlights the importance of considering SCAs in similar cases.