**4. Conclusion**

We report the case of a patient with radiotherapy-induced symptomatic severe mitral regurgitation and an asymptomatic papillary fibroelastoma, which is a rare complication of thoracic radiotherapy that required valve replacement and resection of the tumor. The latent period between radiotherapy and these complications was 10 years and was related to the dose of radiation received. The increase in survival seen in cancer patients has resulted in an increased frequency of these types of complications. This unusual mechanism of formation of an actinic papillary fibroelastoma should be disseminated among cardiologists. In patients who have survived for long periods of time after radiotherapy, it is important to remember that cardiac complications may indeed occur, and the treating physician is responsible for detecting them.
