Rhabdomyoma: ultrastructural features and distribution of desmin, muscle type of intermediate filament protein.
A case of adult type rhabdomyoma in the neck region of a 77-year-old man is presented. In electron microscopy, some tumour cells showed irregularly orientated sarcomere formation with distinct Z-bands. All cells contained rod-like inclusions with attached thin cytoplasmic filaments. When stained with antibodies against desmin many tumour cells showed a diffuse peroxidase reaction, but the tumour also contained cells with cross striations. After phosphotungstic acid hematoxylin staining, dense cytoplasmic inclusions were seen; these structures showed strong affinity to antibodies against desmin. Our results apparently confirm the suggestion that the rod-like inclusions in rhabdomyoma cells are modified Z-bands. The desmin staining patterns in the present tumour may represent different stages in disorderly proliferation and degeneration of rhabdomyoma cells.
D000368:Aged; D003599:Cytoskeleton / Q000378:metabolism; D003893:Desmin; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D009124:Muscle Proteins / Q000378:metabolism*; D012207:Rhabdomyoma / Q000378:metabolism / Q000648:ultrastructure*
D003893:Desmin; D009124:Muscle Proteins