Sellar Wegener Granulomatosis Masquerading as Cabergoline-Resistant Prolactinoma.

BACKGROUND: Pituitary manifestation of Wegener granulomatosis (WG) is extremely rare. When there is pituitary involvement, the granulomatous inflammatory lesions involving the pituitary gland may appear several months to years after the primary diagnosis. CASE DESCRIPTION: We present a case of a 32-year-old woman who presented with galactorrhea, amenorrhea, and elevated serum prolactin levels. Imaging demonstrated a sellar lesion with characteristics of a pituitary macroadenoma. Treatment with cabergoline was initiated, but the tumor continued to grow during a 6-month period. Subsequent surgical exploration revealed a chronic inflammatory lesion; the patient subsequently was diagnosed with WG based on laboratory evaluation and further systemic manifestations. She had a favorable clinical and radiologic response with immunosuppressive doses of glucocorticoids and rituximab. CONCLUSIONS: This case appears to be the first reported of a patient with unknown WG in whom the diagnosis was established after she presented with a sellar lesion mimicking a prolactin-secreting pituitary adenoma on initial presentation requiring surgical resection. The only endocrine abnormality discovered was moderate hyperprolactinemia. Sellar lesions with only moderate elevations in serum prolactin, particularly those that are refractory to medical management with a dopamine agonist, should prompt further investigation to confirm the diagnosis. WG should be part of the differential diagnosis of inflammatory lesions in the sella, the identification of which can facilitate early diagnosis and treatment of this systemic disease for optimal outcome.