Types

 embryonal rhabdomyosarcoma
 alveolar rhabdomyosarcoma
 sclerosing rhabdomyosarcoma

Epidemiology

 5-10% of patients with rhabdomyosarcomas (RMS) are diagnosed during the first year of life

Immunochemistry

 ALK +/- (15 to 45%) (#12405914#)
 WT1 + (cytoplasmic) (#12379755#)

Variants

 pleomorphic rhabdomyosarcoma
 anaplastic rhabdomyosarcoma (#12550764#, #8333559#, #8470759#)
 fusiform cell rhabdomyosarcoma (spindle-cell rhabdomyosarcoma) (#9537474#, #8434703#, #1599014#, #16006807#)

Localization

 head and neck

• parotid region (#11753993#)

 trunk
 biliary tract
 pelvis

• bladder

 paratesticular region
 limbs

Differential diagnosis

 leukemias (#9870849#)

References

 Qualman SJ, Bowen J, Parham DM, Branton PA, Meyer WH; Members of the Cancer Committee, College of American Pathologists. Protocol for the examination of specimens from patients (children and young adults) with rhabdomyosarcoma. Arch Pathol Lab Med. 2003 Oct;127(10):1290-7. PMID: #14521467#

 Qualman SJ, Coffin CM, Newton WA, Hojo H, Triche TJ, Parham DM, Crist WM. Intergroup Rhabdomyosarcoma Study: update for pathologists. Pediatr Dev Pathol. 1998 Nov-Dec;1(6):550-61. PMID: #9724344#