Null cell adenoma of the pituitary gland

Oncocytic lesions of the neuroendocrine system

This paper reviews the pathologic features of lesions which are oncocytic and involve classic endocrine organs. The history of the oncocytic cell, its morphologic and ultrastructural features, and important immunohistochemical findings are reviewed. Oncocytic proliferations including non-neoplastic and neoplastic of the thyroid, parathyroid, adrenal (both cortex and medulla), and pituitary are described. Their clinical relevance, functional capacity and capability, and where appropriate, prognostic implications are discussed. Important and relevant molecular biological information is included where appropriate.

[Nonfuntional pituitary adenomas: evaluation of 36 patients]

We present our experience with 36 cases of nonfunctional pituitary adenomas. These tumors were divided into non reactive and inactive in agreement with the immunohistochemical study. They present with visual symptoms, mainly bitemporal hemianopsia; they were macroadenomas, either invasive or non invasive, in both groups. The treatment is surgical using the transsphenoidal approach. Total resection was possible in about 40% of the cases. Visual improvement occurred in 90% of the patients.