PITUITARY ONCOCYTOMAS - CLINICAL-FEATURES, CHARACTERISTICS IN CELL-CULTURE, AND TREATMENT RECOMMENDATIONS

To determine whether there are significant differences between oncocyt omas and pituitary adenomas, we evaluated clinical features, treatment regimens and outcome in 23 males and 9 females (average age 64 years, range 43-81 years) with the histologic diagnosis of pure pituitary on cocytomas (>95% oncocytes). Symptom duration was six to twelve months in 6 cases (19%) and more than one year in 19 cases (59%). Three patie nts presented with sudden onset of symptoms, and were found to have he morrhage within their tumors. Visual loss (69%) and symptoms of hypopi tuitarism (44%) were the most common presenting complaints. Preoperati ve endocrine profiles revealed abnormalities in most cases, including pituitary insufficiency in 56% and hyperprolactinemia in 59%. The tumo rs were typically large at presentation; all but one had suprasellar e xtension. 28 patients underwent transsphenoidal tumor resections; 4 un derwent subfrontal craniotomies. Gross dural invasion was found at sur gery in 11 cases. At a mean followup of 31 months (range 2-68 months), recurrent tumor was identified in 4 patients (12.5%). Tumor size, dur al invasion, preoperative endocrine profile, and postoperative radioth erapy did not correlate with recurrence. Among seven oncocytomas grown in culture, five demonstrated two distinct cell types consisting of o ncocytes and typical adenoma cells, respectively. Oncocytomas often ha ve a different clinical presentation than functional pituitary adenoma s.