Clinicopathologic Correlates of PIT1 and SF1-Multilineage Pituitary Neuroendocrine Tumors and the Diagnostic Utility of NKX2.2 Immunohistochemistry in Pituitary Pathology

Fatih Mert Doğukan ¹, Hüseyin Karatay ¹, Sabahattin Yüzkan ²

⁰From the Department of Pathology, Başakşehir Çam ve Sakura City Hospital, University of Health Sciences, Istanbul, Turkey (Doğukan, Karatay, Yılmaz-Özgüven).

Archives of Pathology & Laboratory Medicine +

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April 22, 2024

View abstract on PubMed

Summary

PIT1 and SF1-multilineage pituitary neuroendocrine tumors (PitNETs) typically present with acromegaly and have a favorable prognosis. NKX2.2 is a useful marker in diagnosing these specific PitNETs.

Area Of Science

Endocrinology
Oncology
Pathology

Background

Pituitary neuroendocrine tumors (PitNETs) are classified based on transcription factors PIT1, SF1, and TPIT.
PIT1 and SF1-multilineage PitNETs represent a specific subtype with distinct characteristics.

Purpose Of The Study

To delineate the clinicopathologic features of PIT1 and SF1-multilineage PitNETs.
To evaluate the expression of NKX2.2 in PitNETs as a diagnostic marker.

Main Methods

Review of 345 PitNETs, with detailed analysis of 8 PIT1 and SF1-multilineage tumors.
Comparative analysis of NKX2.2 expression in PitNETs and a control group (45 PitNETs).

Main Results

PIT1 and SF1-multilineage PitNETs occurred in patients with a mean age of 41.13 years, commonly presenting with acromegaly.
Histomorphology revealed a pseudopapillary pattern in 5 tumors; all expressed NKX2.2, with 5 showing diffuse staining.
Control group showed lower NKX2.2 positivity (8/45), predominantly focal.

Conclusions

NKX2.2 serves as a valuable additional marker in pituitary pathology.
PIT1 and SF1-multilineage PitNETs are characterized by acromegaly presentation, nonaggressive clinical course, pseudopapillary histomorphology, and NKX2.2 expression.