Sarcoma botryoides of the extrahepatic bile ducts. A light- and electron microscopic study of a case.

The clinical, light- and electron microscopic features of a sarcoma botryoides of the common bile duct of a 2 1/2-year-old boy are reported. Despite the absence of cross-striation under the light microscope, many tumour cells were found to contain abundant thin and thick filaments arranged in a sarcomere-like pattern at the electron-microscopic examination of originally paraffin-embedded material. Ultrastructural examination of embryonal rhabdomyosarcoma may be of value for a definite diagnosis also when only formalin-fixed and paraffin-embedded material is available.