Double adenoma of the pituitary: A somatotroph adenoma colliding with a gonadotroph adenoma

Pituitary collision tumors are rare. They may create difficult diagnostic p roblems and their histogenesis is not clear. We report here an unusual case of a somatotroph adenoma colliding with a gonadotroph adenoma. The 64-year -old man had clinical acromegaly. His blood growth hormone level was elevat ed and magnetic resonance imaging demonstrated a pituitary tumor. The surgi cally removed sellar mass was investigated by histology, immunocytochemistr y and electron microscopy. Morphologic study revealed a collision tumor; on e was a somatotroph adenoma, the other a gonadotroph adenoma. Authors call attention to the difficulties in clinical, imaging and pathological diagnos is. Detailed morphologic studies are needed to establish the presence of tw o distinct tumors composed of two different cell types. (C) 2000, Editrice Kurtis.