Cholesterol granuloma at the sella region: a new method of the differential diagnosis of craniopharyngioma

Cholesterol-granuloma is a pseudotumoral mass that is believed to enlarge by a self-perpetuating sequence of repeated hemorrhages and reparative tissue reaction. Albeit an almost ubiquitous phenomenon throughout the body, cholesterol-granuloma has recently been appreciated as a distinctive lesion mimicking or associated with craniopharyngiomas. Upon review of a surgical series of 15 purported craniopharyngiomas, the authors identified 3 such occurrences. All were characterized by a predominance of slit-like cholesterol clefts with multi-nucleated giant cells embedded in a fibrotic stroma permeated with lipid laden macrophages, lymphocytes, as well as organizing hemorrhage. Non-craniopharyngioma specific cuboidal epithelium was present in one case. The mean age of patients--all males--with cholesterol-granuloma was 26 years, and all but one had an intrasellar tumor component. Clinical symptoms referrable to hypopituitarism predominated. At variance with the above, patients with adamantinomatous or papillary craniopharyngiomas were 23.5 and 46 years old, respectively, and presented with neurological deficits or ones due to hypothalamic involvement by their tumors. With marginal central nervous tissue present in 53 percent of the specimens, 75 percent of adamantinomatous craniopharyngiomas, but only 12 percent of cholesterol-granulomas showed invasive growth. At present cholesterol-granulomas are conceived as a clinicopathologically distinctive lesion of uncertain origin. They most probably represent a clinically relevant entity in the ontogenesis of adamantinomatous craniopharyngiomas with predisposing factors yet to be elucidated.