Myogenin

• Myogenin expression in skeletal muscle nuclei. Intervening tumor nuclei are negative.
• Myogenin expression in skeletal muscle nuclei. Intervening tumor nuclei are negative.
• Myogenin expression in skeletal muscle entrapped by tumor. The nuclei run parallel to one another, a clue that they are entrapped muscle rather than tumor.
• Myogenin expression in mast cells. Tumor cells are negative.
• Myogenin expression in mast cells. Tumor cells are negative.
• Myogenin expression in mast cells. Tumor cells are negative.
• Myogenin expression in mast cells. Tumor cells are negative.
• Myogenin expression in mast cells. Tumor cells are negative.
• Myogenin expression in mast cells. Tumor cells are negative.

1/9

Nuclear regulatory factor that plays an important role in skeletal muscle differentiation. It is expressed by rhabdomyosarcomas.

Synonyms

• myf4

Staining Pattern

• Nuclear

Expression in Neoplastic Entities

Malignant

• Rhabdomyosarcoma

Common Pitfalls

• Sclerosing rhabdomyosarcoma is often only focally and weakly positive for myogenin, although myoD1 is usually strongly and diffusely positive.
• Mast cells often artifactually stain for myogenin, mimicking positive nuclei on low power.