Microphthalmia transcription factor (MITF)

Stains
Microphthalmia transcription factor (MITF)

Author: Lauren N. Stuart, M.D., M.B.A.

Topic Completed: 1 April 2013

Revised: 28 February 2019

Copyright: 2002-2018, PathologyOutlines.com, Inc.

PubMed Search: Microphthalmia transcription factor [title]

Page views in 2018: 3,323

Page views in 2019 to date: 2,367

Table of Contents

Cite this page: Stuart L. Microphthalmia transcription factor (MITF). PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsmitf.html. Accessed August 21st, 2019.

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;62:2834)

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

Microscopic (histologic) images

Images hosted on other servers:

Giant cell tumor of bone, 1C

Positive staining - normal

Macrophages / histiocytes (Am J Surg Pathol 2001;25:197), mast cells, melanocytes, osteoclasts, perivascular epithelioid cells (Mod Pathol 2012;25:100)

Positive staining - disease

Melanoma (usually negative in desmoplastic melanomas, J Cutan Pathol 2010;37:944, Am J Surg Pathol 2001;25:205) and nevi
Perivascular epithelioid tumors including angiomyolipoma, clear cell myomelanocytic tumors of falciform ligament / ligamentum teres
Clear cell sarcoma (2/3), giant cell tumor (Arch Pathol Lab Med 2005;129:360)
Variable results for neurothekeoma (Mod Pathol 2004;17:230, J Cutan Pathol 2014;41:640)

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