Radiation‑induced pure red cell aplasia combined with acquired amegakaryocytic thrombocytopenia in a thymoma after rapid response to radiotherapy: A case report and literature review

Thymoma combined with pure red cell aplasia (PRCA) and acquired amegakaryocytic thrombocytopenia (AAMT) has been rarely reported, often occurring in the initial stage of treatment and after chemotherapy or thymectomy, while PRCA and AAMT occurring after radiotherapy for thymoma has not been reported. The present study describes the case of a 42-year-old female patient with thymoma complicated by radiation-induced PRCA and AAMT after a rapid response to radiotherapy, who was in complete remission without recurrence after adjustment of initial symptomatic therapy to cyclosporine combined with prednisone. After 1 month, the patient underwent complete resection of mediastinal tumor. Next-generation sequencing revealed that the DNA damage repair pathway-related gene MSH3 was mutated, with p.A57P in abundance of 9.21%. To the best of our knowledge, the present study is the first to report that PRCA and AAMT secondary to thymoma after radiotherapy may be associated with increased sensitivity to radiotherapy caused by a mutation in the MSH3 gene.