Intrathyroidal Thymic Carcinoma: A Retrospective Case Series Study.

Objective: Intrathyroidal thymic carcinoma (ITC) is a rare low-grade malignant thyroid tumor. There is neither sufficient understanding of this tumor nor its clinical treatment. This study is to explore the clinicopathological features, treatment, and prognosis of ITC and thereby provide a reference for the diagnosis and treatment of the disease.

Methods: The clinical, pathological, therapeutic, and prognostic data of 13 patients with ITC were retrospectively analyzed.

Results: The case series comprised 7 males and 6 females, with an average age of 51.9 ± 10.1 years. After surgical resection, all patients received post-operative neck radiotherapy at dosages of 60-66 Gy. Five patients with level VI lymph node metastasis additionally received 6 courses of cisplatin chemotherapy. All patients were followed-up for 21-132 months (median = 66 months), and all of them survived without recurrence or metastasis.

Conclusions: The diagnosis of ITC depends mainly on pathological and immunohistochemical results, particularly CD5 positive staining. Surgical resection is the preferred primary treatment modality which can be supplemented with radiotherapy and chemotherapy to reduce the risk of recurrence and metastasis.