Rare Metastatic Patterns in Rhabdomyosarcoma: A Report of Two Cases with Soft Tissue-to-Soft Tissue Spread

Rhabdomyosarcoma is a rare malignant soft tissue sarcoma, primarily affecting children. While common metastatic sites include the lungs, bones and brain, soft tissue-to-soft tissue metastasis is highly unusual. This report presents two rare cases of rhabdomyosarcoma demonstrating soft tissue-to-soft tissue metastasis. The first case involves a 34-year-old man with alveolar rhabdomyosarcoma originating in the right hand and metastasising to the upper arm, pelvis and spinal cord. The second case is a 14-year-old female with paravertebral rhabdomyosarcoma extending to the spinal canal and metastasising to the left forearm. Both patients exhibited rapid disease progression despite initial treatment, highlighting the aggressive nature of rhabdomyosarcoma and its atypical metastatic behaviour. These cases highlight the need for clinicians to consider rare metastatic patterns in rhabdomyosarcoma, emphasising the importance of comprehensive diagnostic imaging and multidisciplinary management for optimal care.