Table 1 Morphologic comparison of spindle lesions of the prostate
Morphology | |
|---|---|
STUMP | Four patterns include (1) degenerative atypia, (2) hypercellular stroma, (3) benign phyllodes-like, (4) myxoid stroma with bland cells |
Stromal sarcoma | Two patterns include (1) solid growth of overtly malignant cells with storiform, epithelioid, fibrosarcomatous, or patternless patterns, (2) malignant phyllodes-like |
Sarcomatoid carcinoma | Admixture of high grade prostatic adenocarcinoma and spindled ‘sarcomatoid’ component with variable heterologous element formation |
Sclerosing adenosis | Foci of well-formed glands and single cells with cellular, spindled stroma |
Leiomyoma | Well-organized smooth muscle fascicles lacking mitotic activity and with little to no atypia |
Leiomyosarcoma | Intersecting fascicles showing mitoses, cytologic atypia and necrosis |
Rhabdomyosarcoma | Primarily embryonal subtype consisting of small round cells with variable eosinophilic cytoplasm, occasional elongated/strap cells and, commonly, a myxoid background |
IMT | Uniform, reactive myofibroblasts with a cell-culture appearance in a background of variable inflammation and extravasated red blood cells; often ALK positive |
Solitary fibrous tumor | Uniform spindled cells with bland nuclei in a ‘patternless’ pattern among a background of ropy collagen |
GIST | Spindled cells in a fascicular growth pattern with perinuclear vacuoles |
