Idiopathic giant-cell granuloma of the pituitary with unusual clinical and histological features.

A surgically treated idiopathic giant-cell granuloma of the pituitary in a 48-year-old man is described. Relative to previously reported cases, this case was unusual both clinically and histologically. Diabetes insipidus was the initial, and a prominent clinical, manifestation. Histological studies showed caseating granuloma or fibrosis in addition to a typical giant-cell granuloma. This is the first published documentation of the association of caseous necrosis in a patient diagnosed as having idiopathic giant-cell granuloma of the pituitary.Endocr Pathol 4:169-173, 1993.