Malignant Mixed Mullerian Tumor (Carcinosarcoma) in the Female Genital Tract: A Retrospective Study From a Single Center in North India.

Background Carcinosarcoma (malignant mixed Mullerian tumor (MMT)) is a rare tumor of the uterus, even rarer in the ovary. Presenting symptoms are indistinguishable from high-grade uterine endometrium carcinoma. Histologically, tumors are biphasic, composed of both epithelial and mesenchymal (sarcomatous) components. The diagnosis of carcinosarcoma presents a challenge due to the need to exclude commonly occurring mimickers, necessitating the application of a broad panel of immunohistochemistry markers. Material and methods This retrospective descriptive study of malignant MMT was conducted over a three-year period (August 2021 to July 2024). A total of six (three ovarian and three uterine) cases diagnosed as malignant MMT were included based on morphology and confirmation by expressing positivity of cytokeratin (CK) and vimentin. All the demographic, clinical, and radiological data, treatment protocols, and survival data were obtained from the medical record department. Dako (Agilent Diagnostics and Genomics Group, Santa Clara, California) antibodies were used for immunohistochemical (IHC) analysis with 1:100 dilutions. Results The mean age of presentation was 51.5 years (35-65 years). The primary tumor site was the uterus in four cases, bilateral ovaries in one case, and unilateral ovaries in one case. Metastasis was seen in two cases. Microscopically, the tumor was biphasic, displaying high-grade carcinomatous and sarcomatous components. Pan-CK was positive in the epithelial component of the tumor, while vimentin was positive in high-grade sarcomatous components. Epithelial membrane antigen (EMA) was positive in three cases, while myogenic was positive in heterologous rhabdomyosarcomatous component in one case. The mean ki-67 was approximately 52% (30%-80%). Conclusions Carcinosarcomas are highly aggressive tumors commonly occurring in elderly females. Uterine carcinosarcomas are rare, and ovarian carcinosarcomas are even rarer. Clinical and histological features resemble high-grade endometrial carcinoma, necessitating an extensive IHC panel to narrow down differentials and confirm the diagnosis. This study highlights the histological and IHC features and emphasizes that early diagnosis plays a crucial role in disease management.