title: Multiple endocrine neoplasia type 1-associated thyrotropin-producing pituitary carcinoma: report of a probable de novo example.
abstract: Pituitary carcinomas are exceedingly rare. At present, the sole diagnostic criterion is metastatic spread, either craniospinal or systemic. There is no agreement on a histologic, immunohistochemical, and/or ultrastructural definition. We report a clinically and morphologically well-documented example of pituitary thyrotropin cell carcinoma in a man with multiple endocrine neoplasia type 1 syndrome. The tumor produced thyrotropin, alpha-subunit, and prolactin and, through electron microscopy, was found to consist solely of Thyrotroph cells. Over a protracted course, craniospinal and systemic metastases were noted. The primary and metastatic deposits of this aggressive tumor were studied. To our knowledge, this tumor is the first reported case of thyrotropin cell carcinoma occurring in association with the multiple endocrine neoplasia type 1 syndrome. The literature regarding thyrotropin carcinomas is reviewed. Based on the study of several biopsies during disease progression, we believe that the carcinoma originated de novo without an intermediary adenoma phase.
authors.affiliation: Department of Laboratory Medicine and Pathology, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, USA. scheithauer.bernd@mayo.edu
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Scheithauer
authors.forename: Kalman
authors.initials: K
authors.lastname: Kovacs
authors.forename: Vania
authors.initials: V
authors.lastname: Nose
authors.forename: Matilde
authors.initials: M
authors.lastname: Lombardero
authors.forename: Yoshiyuki R
authors.initials: YR
authors.lastname: Osamura
authors.forename: Ricardo V
authors.initials: RV
authors.lastname: Lloyd
authors.forename: Eva
authors.initials: E
authors.lastname: Horvath
authors.forename: Axel
authors.initials: A
authors.lastname: Pagenstecher
authors.forename: Jürgen E
authors.initials: JE
authors.lastname: Bohl
authors.forename: Dominique S
authors.initials: DS
authors.lastname: Tews