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Medical Term:

null-cell adenoma


Definition: an adenoma of the hypophysis composed of cells for which there is no overt evidence of hormone production, but which usually produces hypopituitarism and visual disturbances by compression of adjacent structures; approximately one third of these tumors have cells with abundant mitochondria (oncocytes) that are somewhat larger than the monocytic null cells.

Synonym(s): undifferentiated cell adenoma

© Copyright 2016 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.