title: A composite silent corticotroph pituitary adenoma with interspersed adrenocortical cells: case report.
abstract: OBJECTIVE
  A case report of an extraordinary sellar pituitary tumor composed of corticotrophs and adrenocortical cells is presented. To our knowledge, this is only the second one reported in the literature.
  
  
  METHODS
  An 18-year-old female patient presented with amenorrhea.
  
  
  METHODS
  Investigations revealed a sellar mass, which was excised transsphenoidally. Histologically, two cell types could be readily distinguished, i.e., small basophilic cells that were positive for periodic acid Schiff and adrenocorticotropic hormone and large cells with abundant, slightly vacuolated, eosinophilic cytoplasm that were negative for periodic acid Schiff and adrenocorticotropic hormone. The nature of the tumor was revealed by ultrastructural examination, thus highlighting the importance of this technique in the investigation of pituitary adenomas. Immunohistochemistry with a panel of steroidogenic dehydrogenases and hydroxylases was positive in the large cells, confirming these as adrenocortical cells.
  
  
  CONCLUSIONS
  We suggest that the designation "composite silent corticotroph pituitary adenoma with adrenocortical cells" is an appropriate name for this tumor. The explanation for the presence of the two cell types is obscure. Two theories are considered, as were proposed by the authors of the previous case report regarding the same entity, i.e., 1) the possibility of misplaced embryonic adrenocortical cells and 2) the presence of uncommitted stem cells that differentiate into adrenocortical cells.
authors.affiliation: Department of Pathology, Wellesley Central Hospital and the University of Toronto, Ontario, Canada.
authors.forename: C I
authors.initials: CI
authors.lastname: Coiré
authors.forename: E
authors.initials: E
authors.lastname: Horvath
authors.forename: K
authors.initials: K
authors.lastname: Kovacs
authors.forename: H S
authors.initials: HS
authors.lastname: Smyth
authors.forename: H
authors.initials: H
authors.lastname: Sasano
authors.forename: K
authors.initials: K
authors.lastname: Iino
authors.forename: D S
authors.initials: DS
authors.lastname: Feig
mesh_terms: D000236:Adenoma / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*; D000293:Adolescent; D000302:Adrenal Cortex / Q000473:pathology*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008854:Microscopy, Electron; D010911:Pituitary Neoplasms / Q000175:diagnosis / Q000378:metabolism / Q000473:pathology*
chemical_list: D000324:Adrenocorticotropic Hormone