SMARCA4-deficient dedifferentiated ovarian carcinoma with rapid progression during adjuvant platinum-based...

Dedifferentiated ovarian carcinomas (DDOC) are rare and aggressive malignancies characterized by a mixture of differentiated and undifferentiated tumor components, often associated with poor prognosis. This case report describes a 55-year-old woman initially diagnosed with early-stage high-grade endometrioid ovarian carcinoma who experienced rapid disease progression during adjuvant platinum-based chemotherapy, culminating in death within 4 months. Retrospective molecular analyses revealed pathogenic variants in the SMARCA4 gene, leading to a revised diagnosis of DDOC. The tumor exhibited resistance to conventional chemotherapy, highlighting the challenges associated with managing this aggressive tumor subtype. In our case, molecular profiling identified two potentially targetable alterations: biallelic SMARCA4 loss and a pathogenic PIK3CA mutation, both of which may inform future therapeutic strategies. This case underscores the importance of integrating molecular diagnostics into routine practice for accurate classification and highlights the urgent need for personalized treatment strategies, including targeted and immunotherapy options, for this formidable tumor subtype.