Cystic Lesions of the Pituitary: Clinicopathological Features Distinguishing Craniopharyngioma, Rathke’s Cleft Cyst, and Arachnoid Cyst

Abstract

The challenge of distinguishing preoperatively among craniopharyngioma (CR), Rathke’s cleft cyst (RCC), and intrasellar arachnoid cyst (AC) remains a difficult one, but an accurate distinction will aid treatment selection and help to predict the outcome. This study, the largest combined series reported to date, included 21 adults with CR, 26 with RCC, and 5 with AC. The average follow-up period was just under 6 years. Patients with AC were significantly older when they first underwent operation than those in the other groups. Females predominated in the RCC group. Patients with AC had been symptomatic for a shorter time, but the differences were not significant. Pituitary hormone insufficiency and neurological and/or ophthalmological deficits were frequent when patients with CR or RCC were first seen. Endocrine dysfunction was documented in 95 percent of patients with CR but in only 40 percent of those with AC. In patients with CR, the most common features were amenorrhea, impotence or reduced libido, and hyperprolactinemia. Diminished libido was present in two-thirds of RCC patients. Although 80 percent of CRs were >20 mm in diameter radiographically, this was the case for only 18 percent of RCCs. Two-thirds of CR lesions were suprasellar, but all RCC and AC lesions were intrasellar. At least 60 percent of patients in all groups had neurological dysfunction preoperatively. One patient with CR died postoperatively of massive bleeding. Patients with CR had the least favorable prognosis. Significantly more of them required replacement hormones postoperatively. Amenorrhea and galactorrhea were most resistant to surgical treatment. Recurrence rates were 62 percent for CR, 19 percent for RCC, and 20 percent for AC. Cumulative rates of recurrence-free survival for patients with CR were 57 percent at 5 years, 48 percent at 10 years, and 43 percent at 20 years. The figures were 85, 81, and 81 percent, respectively, for RCC and 100, 80, and 80 percent, respectively, for AC. J Clin Endocrinol Metab 1999;84:3972–3982