Leiomyosarcoma showing partial synthetic-phase differentiation.
An unusual leiomyosarcoma in the thigh of a 53-year-old woman is described. Tumor cells were spindled and positive for muscle immuno-markers. Some cells exhibited typical smooth-muscle ultrastructure--abundant myofilaments, focal densities, attachment plaques, plasmalemmal caveolae, and lamina. Others had fewer myofilaments and prominent rough endoplasmic reticulum. These features indicated a variable phenotype that included synthetic-phase (matrigenic) differentiation. Synthetic-phase cells were distinguished from myofibroblasts by typical smooth-muscle surface features in the absence of fibronexus junctions. In a subset of cells myofilaments were absent, but structures resembling solitary focal densities were identified. These are discussed as possible indicators of a primitive level of smooth-muscle differentiation.
Eyden
Brian
B
Christie Hospital NHS Trust, Manchester, United Kingdom. Bryan.Eyden@christie-tr.nwest.nhs.uk
Banerjee
S Sankar
SS
D014408:Biomarkers, Tumor / Q000032:analysis; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007890:Leiomyosarcoma / Q000737:chemistry / Q000601:surgery / Q000648:ultrastructure*; D008854:Microscopy, Electron; D008875:Middle Aged; D016609:Neoplasms, Second Primary / Q000473:pathology; D016196:S Phase; D012983:Soft Tissue Neoplasms / Q000737:chemistry / Q000601:surgery / Q000648:ultrastructure*; D013848:Thigh
D014408:Biomarkers, Tumor