Osteolipomas of the tuber cinereum.

Osteolipomas of the tuber cinereum traditionally have been classified as meningeal lipomas that are located at the tuber cinereum. Examination of two cases and a review of 22 others found in the literature show that these lesions exhibit a remarkable consistency in their size and in their location between the corpora mamillaria and the pituitary stalk, and that approximately half of them contain a well-organized bone spherule with a central marrow space. These aspects differ from the features of meningeal lipomas in general; reasons are given for considering that the osteolipomas are displaced elements of the mesenchyme encompassing walls of the craniopharyngeal duct.