Carcinosarcomas of Ovary/Fallopian Tube: A Rare Entity

Abstract

Abstract Introduction/Objective Adnexal carcinosarcomas (MMMTs) are rare tumors (1–4% ovarian carcinomas) with worse prognosis than high grade serous carcinomas (HGS) at similar stage. They typically present at age 64–66, often with peritoneal involvement. They are biphasic tumors with stem cells undergoing divergent epithelial and sarcomatous differentiation. The epithelial component is usually HGS and drives progression of the tumor. The mesenchymal component can be homologous with high-grade spindled cells or heterologous with malignant cartilage, bone, muscle or fat. Metastases are mostly epithelial; metastatic sarcomatous components are unusual. We reviewed our single- institutional experience of adnexal MMMTs. Methods We reviewed our pathology database (2001–2019) to find all cases of adnexal MMMTs. We reviewed their histological features, histology of metastases and clinical outcomes. Results Our series consisted of 12 cases. Patients aged 41–82 years. The primary tumor sites were ovary (6 cases, 50%), fallopian tube (4, 33%), 1 each (8%) in paratubal region and infundibular ligament. Fallopian tube was involved in 8/12 cases (4 cases as primary MMMT, 4 cases with STIC or HGS). Epithelial component was serous (75%), endometrioid (17%) and mucinous (8%). Sarcomatous component was homologous in 5 cases (41%), heterologous in 7 cases: cartilage (33%), cartilage/muscle (8%), muscle (8%), cartilage/muscle/fat (8%). 3 cases were FIGO stage I, 9 had peritoneal metastases (8 stage III, 1 stage IV). Six cases had metastatic HGS; 3 had metastatic HGS with sarcomatous component, 2 with heterologous elements. Aberrant p53 pattern was seen in 7/12 and TP53 mutation was noted in 6/12. Ten patients received cytoreductive surgery and chemotherapy. 7 patients are alive with progression free survival ranging 6–59 months, 2 survived for 25 and 29 months, 3 are lost to follow-up. Conclusion Metastatic sarcomatous heterologous elements are rare in uterine carcinosarcomas and may suggest adnexal origin. They may correlate with worse outcome; in our series, 1/2 died after 29 months, the other was lost to follow-up. Fallopian tube involvement (75% of our cases) is of significance as identical TP53 mutation has been identified in a case report of ovarian carcinosarcoma with fallopian tube STIC. Also, our 2 cases of infundibular ligament and paratubal region may indicate seeding from fallopian tube. Further studies are needed to confirm the correlation.