Test Catalog

Test ID: MYOD1    
Myogenic Differentiation Antigen 1 (MYOD1) Immunostain, Technical Component Only

Useful For Suggests clinical disorders or settings where the test may be helpful

Marker of skeletal muscle differentiation

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Myogenic differentiation antigen 1 (MyoD1) is a myogenic nuclear regulatory protein that is normally expressed during embryogenesis. Nuclear expression of MyoD1 is restricted to myoblasts of developing skeletal muscle tissue. MyoD1 is present in the majority of rhabdomyosarcomas.

Interpretation Provides information to assist in interpretation of the test results

This test does not include pathologist interpretation, only technical performance of the stain. If interpretation is required, order PATHC / Pathology Consultation for a full diagnostic evaluation or second opinion of the case.


The positive and negative controls are verified as showing appropriate immunoreactivity and documentation is retained at Mayo Clinic Rochester. If a control tissue is not included on the slide, a scanned image of the relevant quality control tissue is available upon request, call 855-516-8404.


Interpretation of this test should be performed in the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Age of a cut paraffin section can affect immunoreactivity. Stability thresholds vary widely among published literature and are antigen dependent. Best practice is for paraffin sections to be cut within 6 weeks.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Furlong MA, Mentzel T, Fanburg-Smith JC: Pleomorphic rhabdomyosarcoma in adults: a clinicopathologic study of 38 cases with emphasis on morphologic variants and recent skeletal muscle-specific markers. Mod Pathol. 2001 Jun;14(6):595-603. doi: 10.1038/modpathol.3880357

2. Sebire NJ, Malone M: Myogenin and MyoD1 expression in paediatric rhabdomyosarcomas. J Clin Pathol. 2003 Jun;56(6):412-416. doi: 10.1136/jcp.56.6.412

3. Cessna MH, Zhou H, Perkins SL, et al: Are myogenin and myoD1 expression specific for rhabdomyosarcoma? A study of 150 cases, with emphasis on spindle cell mimics. Am J Surg Pathol. 2001 Sept;25(9):1150-1157. doi: 10.1097/00000478-200109000-00005

4. Kohsaka S, Shukla N, Ameur N, et al: A recurrent neomorphic mutation in MYOD1 defines a clinically aggressive subset of embryonal rhabdomyosarcoma associated with PI3K-AKT pathway mutations. Nat Genet. 2014;46(6):595-600. doi: 10.1038/ng.2969