A Case of Metastatic Thymoma Responsive to Treatment With ¹⁷⁷Lu-DOTATATE

We describe a case of a 74-year-old woman with germline BRCA2 mutation, with an incidental diagnosis of metastatic thymoma presenting as a mediastinal mass with cardiac muscle and lymph node involvement. Despite surgical and radiotherapy treatment, there was marked advancement with new lung and liver metastases. All lesions demonstrated 68Ga-DOTATATE PET/CT uptake, and the patient received 4 peptide receptor radionuclide therapy cycles with 177Lu-DOTATATE, with pronounced reduction in the size of the liver, cardiac, and pleural lesions. This is the first case to demonstrate partial response to peptide receptor radionuclide therapy in metastatic thymoma, thus suggesting possible treatment option to refractory and advancing metastatic thymoma.