The primary difference between rhabdomyoma and rhabdomyosarcoma lies in their nature: rhabdomyoma is a benign tumor, while rhabdomyosarcoma is a malignant (cancerous) tumor of muscle tissue.
Here's a breakdown of their differences:
| Feature | Rhabdomyoma | Rhabdomyosarcoma |
|---|---|---|
| Nature | Benign (non-cancerous) | Malignant (cancerous) |
| Growth Pattern | Well-demarcated lesions, no invasion of surrounding tissue | Invasive, infiltrates surrounding tissue |
| Cellular Features | Mature, well-differentiated muscle cells | Primitive mesenchymal cells in various stages of myogenesis |
| Cellular Staining | N/A | Heterogeneous nuclear staining for myogenin |
In more detail:
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Rhabdomyoma: This is a rare, benign tumor of striated (skeletal) muscle. It does not spread to other parts of the body. The provided reference states that histopathologically, rhabdomyoma is characterized by well-demarcated lesions with no invasion of the surrounding tissue.
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Rhabdomyosarcoma: This is a malignant tumor arising from primitive muscle cells. It's a type of soft tissue sarcoma and can spread (metastasize) to other parts of the body. As stated in the reference, Embryonal rhabdomyosarcoma is composed of primitive mesenchymal cells in various stages of myogenesis and shows heterogeneous nuclear staining for myogenin. This means the cancer cells are less mature than normal muscle cells and show specific protein markers when stained in the lab.
Essentially, rhabdomyoma is a non-cancerous growth that stays localized, while rhabdomyosarcoma is a cancerous growth that can invade surrounding tissues and spread to distant sites.
