Double Adenomas of the Pituitary: Transcription Factors Pit-1, T-pit, and SF-1 Identify Cytogenesis and Differentiation

Abstract

The diagnosis of double adenomas of the pituitary can be very complex and is usually suspected on histological assessment of a specimen and confirmed by immunohistochemical and ultrastructural studies. The most commonly applied technique is currently immunohistochemical staining to localize the six pituitary hormones. Application of this technique may fail to identify double adenomas when hormone immunoreactivity is weak or absent in one or both cell populations. We examined specimens from eight patients diagnosed with double adenomas over a 15-yr period. We tested the ability to detect the difference in the two adenomas in each case using three immunostains for the pituitary transcription factors Pit-1, T-pit, and SF-1. We conclude that immunohistochemical localization of the transcription factors Pit-1, T-pit, and SF-1 accurately detects and classifies the distinct cytodifferentiation of double adenomas of the pituitary.

A somatotropin-producing pituitary adenoma with an isolated adrenocorticotropin-producing pituitary adenoma in a female patient with acromegaly, subclinical Cushing’s disease and a left adrenal tumor

“…Although several combinations of hormonally-functioning double pituitary adenomas have been reported [4][5][6][7][15][16][17][18][19][20][21][22][23][24][25][26][27][28], the coexistence of acromegaly and pituitary Cushing's disease is rare [3,[8][9][10][11] (Table 4). Although our case resembles previous cases in terms of the immunohistochemical staining pattern, ours differs in the lack of Cushingoid features (i.e.…”

Isolated double adrenocorticotropic hormone-secreting pituitary adenomas: A case report and review of the literature

“…The oldest reported patient was 80 years old (8). The majority of patients were aged 41.5-45.5 years.…”

“…The majority of patients were aged 41.5-45.5 years. On the basis of preoperative, intraoperative and postoperative evaluations, 42 patients were diagnosed with clearly separated double pituitary adenomas (1-4,8,10-14,17-25), 36 patients with contiguous pituitary adenomas (6)(7)(8)(9)11,12,14,(26)(27)(28)(29), and 3 patients with 3 pituitary adenomas (11,22,23).…”

“…There are numerous different theories on the pathogenesis of pituitary tumors, including genetic mutations, autocrine/paracrine interactions, altered hypothalamic function, abnormal extrapituitary regulatory mechanisms, epigenetic modification, and microRNAs and large non-coding RNAs such as maternally expressed 3 (8,10,34,35). Kim et al (10) reported 2 patients with a family history of pituitary adenomas, suggesting that genetic abnormalities may be associated with the pathogenesis of double or multiple pituitary tumors.…”

“…Certain cases have been diagnosed on the basis of the expression of ≥2 types of hormones and immunohistochemical staining results by pathologists (5). The combined expression of adrenocorticotropic hormone (ACTH) and prolactin (PRL) is the most common characteristic of double or multiple pituitary adenomas (5); however, immunohistochemical studies on the diagnosis of double or multiple pituitary adenomas have not been fully trusted by clinical doctors when there is cross-reactivity of antisera and an insufficient specimen (8). The doctor making the diagnosis of double or multiple pituitary adenomas should correlate the patient's symptoms with the type of hormone produced by the tumor, since, in the majority of cases, the diagnosis of double or multiple pituitary adenomas is made only on the basis of immunohistochemical staining results.…”