Liver metastases from pituitary carcinomas mimicking visceral well-differentiated neuroendocrine tumors: A series of four cases

Elise R. Venable, Sarah E. Kerr, M. Beatriz S. Lopes, Karra A. Jones, Andrew M. Bellizzi, Taofic Mounajjed, Aditya Raghunathan, Oksana Hamidi, Thorvardur R. Halfdanarson, Mabel Ryder, Rondell P. Graham

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Background: Pathologists frequently encounter neuroendocrine tumors (NETs) presenting as multiple liver masses in routine practice. Most often, these are well-differentiated tumors with characteristic histologic features. In contrast, pituitary carcinoma is very rare, and there is limited data on its natural history and pathologic characterization. Methods: The aim of this study was to describe clinical characteristics, histomorphology, immunophenotype and follow-up of pituitary carcinoma involving the liver and mimicking well-differentiated NETs of visceral origin. We selected a group of well-differentiated NETs of the pancreas to use as immunophenotypic controls. We identified 4 patients (age range, 51 to 73) with pituitary corticotroph carcinoma with liver metastases. Three patients presented with Cushing syndrome. Results: All cases histologically resembled well-differentiated NETs of visceral origin with Ki-67 proliferation indices of 5-42% and expression of T-PIT; metastatic tumors were not immunoreactive with CDX2, Islet 1 or TTF-1. Conclusions: Frequently, these cases display adrenocorticotropic hormone (ACTH) secretion and pituitary-specific transcription factor immunohistochemistry may be used as a reliable marker to distinguish metastatic pituitary carcinoma from NETs of visceral origin in addition to delineating a corticotroph carcinoma from somatotroph, lactotroph, thyrotroph, and gonadotroph lineage. Although rare, the differential diagnosis of pituitary carcinoma should be considered in metastatic well-differentiated NETs in which the site of origin is uncertain. In summary, pituitary corticotroph carcinoma can metastasize to the liver and mimic well-differentiated NET.

Original languageEnglish (US)
Article number81
JournalDiagnostic Pathology
Volume15
Issue number1
DOIs
StatePublished - Jul 4 2020
Externally publishedYes

Keywords

  • Cushing syndrome
  • Liver metastasis
  • Neuroendocrine tumor
  • Pituitary carcinoma
  • Pituitary tumor

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Histology

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