Fig. 3

The tumor tissue is fragmented (A). In non-myxoid areas, tumor cells exhibit either an epithelial-like or spindle-shaped morphology, with biphasic cytoplasm, moderate cellular pleomorphism, prominent nucleoli, and a diffuse, sheet-like arrangement. (B-D). In myxoid areas, epithelioid or spindle-shaped tumor cells proliferate singly or in a loosely cohesive reticular or clustered manner (E, F). The tumor cells show focal positivity for MUC1 (G), as well as diffuse positivity for ER (H). In contrast, the tumor cells are negative for Keratin (I) and CD34 (J). SMARCB1 expression is completely absent in all tumor cells (K, vascular reactivity used as an internal positive control). The Ki-67 proliferation index is approximately 20% (L)