Unusual clinical course Background: Thymic carcinoma is a rare malignant neoplasm. High-grade thymic carcinoma has a high recurrence rate following surgery, and a low 5-year survival rate. Approximately 30% of patients with thymic carcinoma will be asymptomatic at the time of diagnosis. Extrathoracic metastasis on presentation is uncommon. Treatment of the primary tumor includes surgery, chemotherapy, and fractionated radiation. A rare case of thymic carcinoma that presented with bone and cerebral metastases is reported in a patient who responded well to stereotactic radiosurgery and chemotherapy. Case Report: A 63-year-old woman presented to the hospital for evaluation of hip pain. She was diagnosed with a lytic bone lesion of the right femur and brain metastasis. Biopsies from the mediastinal mass and right femur showed histological features consistent with carcinoma. Immunohistochemistry showed positive immunostaining of the tumor cells for the c-kit receptor (CD117) and CD5, supporting a diagnosis of stage IVb thymic carcinoma. Treatment included stereotactic radiosurgery, which delivered multiple radiation beams to the tumor tissue from different directions to target the tumor without affecting normal tissues. She was treated as an outpatient with carboplatin and taxol after stereotactic radiosurgery. The patient recovered well following treatment. Conclusions: A case of thymic carcinoma with bone and cerebral metastases was successfully treated with stereotactic radiosurgery and chemotherapy.