rhabdomyosarcoma
Pronunciation: RAB-doh-MY-oh-sar-KOH-mah
The most common soft tissue sarcoma in children, arising from primitive mesenchymal cells that differentiate toward skeletal muscle.
Full Definition
Rhabdomyosarcoma is the most frequent soft tissue malignancy in pediatric patients, accounting for approximately 50% of childhood soft tissue sarcomas. It arises from primitive mesenchymal cells capable of skeletal muscle differentiation and can occur anywhere in the body, with common sites including the head and neck, genitourinary tract, and extremities. Two main histological subtypes exist: embryonal (more common and better prognosis) and alveolar (more aggressive). Imaging characteristics vary by location but typically show a heterogeneous soft tissue mass with possible hemorrhage and necrosis. Cross-sectional imaging with MRI or CT is essential for local staging, while PET-CT may be used for detecting distant metastases. The tumor has a propensity for lymphatic and hematogenous spread.
Usage
Usage note: One word, not hyphenated. May be abbreviated as RMS in subsequent references. Specify histological subtype when known.
In Context
- "The enhancing parameningeal mass is concerning for rhabdomyosarcoma." — Pediatric oncology radiology
- "Embryonal rhabdomyosarcoma of the bladder requires multimodal therapy." — Tumor board discussion