Stains
Microphthalmia transcription factor (MITF)

Author: Lauren N. Stuart, M.D., M.B.A. (see Authors page)

Revised: 10 November 2015, last major update April 2013

Copyright: (c) 2002-2015, PathologyOutlines.com, Inc.

PubMed Search: Microphthalmia transcription factor [title]

Definition / General
  • Encodes a transcription factor on chromosome 3p14.1 essential for development and survival of melanocytes (Am J Surg Pathol 2001;25:51)
Terminology
  • Also known as MI, WS2, CMM8, WS2A, bHLHe32 (Entrez Gene: MITF microphthalmia-associated transcription factor)
Pathophysiology
  • Plays key role in transcription regulation of pigmentation enzyme genes tyrosinase and tyrosinase-related proteins 1 and 2
  • Acts with Ets family factor PU.1 to activate TRAP gene
  • Regulates expression of cathepsin K in osteoclasts (Mod Pathol 2012;25:100)
  • Regulates function of pancreatic beta cells and may play a role in glucose homeostasis (Diabetes 2013 Apr 22 [Epub ahead of print])
Clinical Features
  • Heterozygous mutations cause Waardenburg syndrome IIA (autosomal dominant, white forelock and hearing loss)
Interpretation
  • Nuclear immunostain
Uses by Pathologists
  • Diagnosis of perivascular epithelioid cell tumors including angiomyolipoma (Am J Surg Pathol 2001;25:65)
  • Diagnosis of melanoma and other melanogenic tumors
Micro Images
Missing Image

Giant cell tumor of bone, 1C



Nature images:



Positive Staining - Normal
Positive Staining - Disease
Negative Staining
  • Basal cells, epithelium, peripheral nerve sheath, smooth muscle
  • Atypical fibroxanthomas, carcinoma, fibrohistiocytic lesions (Am J Surg Pathol 2001;25:51), germ cell tumors, malignant peripheral nerve sheath tumor, melanocytic schwannoma, neurofibromas, palisaded and encapsulated neuroma