+ General Considerations

  • Malignant tumor of striated muscle
  • Signalment: young dogs
  • Biologic behaviour: locally invasive with metastasis to lungs, liver, spleen, kidneys, and adrenal gland
  • Grape-like appearance has resulted in description of botryoid, particularly in the urinary bladder
  • Histology: large, pleomorphic elongated tumor cells (= strap cells) with cross-striation in eosinophilic cytoplasm
  • Poor prognostic factors in humans include metastatic disease and poor response to chemotherapy
  • Age, location, nodal status, and histologic subtype (i.e., embryonal, botryoid, alveolar or pleomorphic) are not prognostic