Extremely Rare Primary Gastric Alveolar Rhabdomyosarcoma in an Adult: 18F-FDG PET/CT Findings

Approximately 85-90% of all rhabdomyosarcoma (RMS) cases occur in children and adolescents.In adults, RMS accounts for only 2-5% of all soft tissue sarcomas.The annual incidence in adults is 0.3-0.5 per 1,000,000 and is classified as a "very rare tumor."More than 95% of RMSs are extragastric.Primary gastric RMS is reported extremely rarely in adults, and the estimated incidence is <0.01/1,000,000/year.This rate is <0.01% of all gastric malignancies and <1% of all adult RMSs.We report the 18 F-fluorodeoxyglucose positron emission tomography/computed tomography findings in an adult with primary gastric alveolar RMS, highlighting the metabolic characteristics of this extraordinarily rare malignancy.