MKI67 and neoplasm: Differential diagnosis should primarily include: Uterine sarcomas: These malignancies typically demonstrate aggressive behavior, histologically characterized by marked cellular atypia, frequent mitotic figures, coagulative tumor necrosis, and elevated Ki67 proliferation indices.[8]Intravenous leiomyomatosis: Intravenous leiomyomatosis is defined by the intravascular proliferation of neoplastic smooth muscle cells, with gross and microscopic evidence of tumor extension within venous structures.