PIT-1 by IHC-12376 - Technical only, 12379 - Technical & interpretation

Test info

PIT-1 by IHC
12376 - Technical only, 12379 - Technical & interpretation
  • All IHC stains will include a positive control tissue
  •  Pit-1 immunostain is useful for diagnosis of the family of pituitary adenomas that display development along the Prolactin-Growth Hormone-TSH spectrum
  • It is also present within normal anterior pituitary gland, so the presence of pituitary adenoma must be confirmed on H&E stains (occasionally with the support of ancillary stains such as reticulin stains for normal adenohypophyseal architecture).

Note: Pit-1 should generally be used in conjunction with other pituitary stains to help subtype pituitary adenomas.



Submit a formalin-fixed, paraffin embedded tissue block


Formalin-fixed, paraffin embedded (FFPE) tissue block


FFPE tissue section mounted on a charged, unstained slide


Ambient (preferred)

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


AHL - Immunohistochemistry
Mo - Fr
1 - 2 days

Immunohistochemical staining and microscopic examination

Clinical and Interpretive info


If requested, an interpretive report will be provided



  • The PIT-1 gene encodes a transcription factor involved in anterior pituitary development, where it is expressed in cell types responsible for prolactin, growth hormone and beta thyroid stimulating hormone (beta-TSH, also known as beta-thyrotropin) production
  • The antibody to the protein Pit-1 reacts with this transcription factor in normal adenohypophysis and in pituitary adenomas, which show development along this line
  • Hence, pituitary adenomas that produce prolactin, growth hormone or beta-TSH (or combinations thereof), are expected to be positive using this stain1, 2

 Staining pattern

  • Strong nuclear staining is observed within lactotrophs, somatotrophs, mammosomatotrophs, thyrotrophs and pituitary adenomas that develop along these lines of differentiation


  1. Friend KE, Chiou YK, Laws ER, Jr., Lopes MB, Shupnik MA. Pit-1 messenger ribonucleic acid is differentially expressed in human pituitary adenomas. J Clin Endocrinol Metab. 1993;77(5):1281-6.
  2. Pellegrini I, Barlier A, Gunz G, Figarella-Branger D, Enjalbert A, Grisoli F, et al. Pit-1 gene expression in the human pituitary and pituitary adenomas. J Clin Endocrinol Metab. 1994;79(1):189-96.


88342 - 1st stain
88341 - each additional stain