POU2F3 nuclear positivity has been associated with small cell carcinoma with low/no expression of  TTF-1 and standard neuroendocrine markers (CD56, INSM1, chromogranin, synaptophysin) .  Compared with other molecular subtypes of small cell carcinoma, the POU2F3 subtype is reported to have a higher frequency of combined histology.

Prepare a formalin-fixed, paraffin embedded (FFPE) tissue block

FFPE tissue block

Tissue section mounted on a charged, unstained slide

Ambient (preferred)

• Unlabeled/mislabeled
• Insufficient tissue
• Slides broken beyond repair

Immunohistochemical staining and microscopic examination

If requested, an interpretive report will be provided.

Specifications

POU2F3 (POU class 2 homeobox 3/OCT-11/PLA-1/SKN-1) is a transcription factor of cellular differentiation of tuft cells in the skin, oropharyngeal, gastrointestinal and respiratory tract.  POU2F3 has been described as a molecular subtype of small cell carcinoma, comprising approximately 8% of small cell carcinomas.

Staining pattern Nuclear

References

1. Baine, M. K. et al. SCLC subtypes defined by ASCL1, NEUROD1, POU2F3, and YAP1: a comprehensive immunohistochemical and histopathologic characterization. J. Thorac. Oncol. 15, 1823–1835 (2020).
2. Huang, Y.-H. et al. POU2F3 is a master regulator of a tuft cell-like variant of small cell lung cancer. Gene Dev. 32, 915–928 (2018).
3. Rekhtman, N. Lung neuroendocrine neoplasms: recent progress and persistent challenges. Mod Pathol 35, 36–50 (2022). https://doi.org/10.1038/s41379-021-00943-2.