Background: Ovarian carcinomas are currently managed as a single entity with no stratification for histological type. The foundation of treatment is a combination of surgery and chemotherapy. Women who are not candidates for up-front debulking surgery, either because of performance status or widespread disease, are often offered neoadjuvant chemotherapy in an effort to shrink their tumour and make resection possible.
Case: A 76-year-old woman was treated with neoadjuvant platinum-based chemotherapy for advanced ovarian cancer. At interval debulking surgery, she was found to have a concurrent mucinous colorectal carcinoma that was essentially unaffected by her treatment.
Conclusion: This case serves as an in vivo demonstration of the greater resistance to platinum-based treatments of mucinous carcinomas than of the "typical" high-grade serous ovarian cancer.