Thyrotropin-secreting pituitary tumours: Significance of "atypical adenomas" in a series of 10 patients and association with Hashimoto thyroiditis as a cause of delay in diagnosis

G. Marucci, M. Faustini-Fustini, A. Righi, E. Pasquini, G. Frank, R. Agati, M. P. Foschini

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Background: Thyrotropin-secreting adenomas (TSH-As) are rare and, according to the World Health Organization criteria (WHO 2004), a significant proportion of them present features of atypical adenomas at the time of diagnosis. Aims: To determine the frequency of "atypical adenomas" and the significance of this definition as regards follow-up. To investigate their possible association with Hashimoto thyroiditis, leading to a delay in diagnosis. Methods: Case notes for patients who underwent transsphenoidal surgery between 1992 and 2006 were retrieved. Follow-up ranged from 6 to 180 months. Results: Ten cases of TSH-As out of 908 pituitary adenomas were selected. Before surgery, eight patients had hyperthyroidism, one was euthyroid and another one showed hypothyroidism associated with Hashimoto thyroiditis. All cases were macroadenomas; six of them were invasive. Three cases met the criteria for classification as atypical. In none of the cases, including the three "atypical adenomas", were clinical or radiological signs of recurrence observed. Conclusions: The three cases with features of atypical adenoma did not recur or metastasise, suggesting that, at least in the present series, a strict relationship between the morphological criteria for diagnosing atypical adenomas and biological behaviour may be sometimes lacking. Furthermore, the casual association of TSH-As with Hashimoto thyroiditis may led to an adjunctive delay in diagnosis, because of low thyroid hormone levels.

Original languageEnglish
Pages (from-to)455-459
Number of pages5
JournalJournal of Clinical Pathology
Issue number5
Publication statusPublished - May 2009


ASJC Scopus subject areas

  • Pathology and Forensic Medicine

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