The differential diagnosis for an anterior mediastinal mass includes lymphoma, germ-cell tumor, parathyroid tumor, pericardial cyst, thymic mass, metastatic disease, and thyroid tumor. Thymic masses represent a broad category that includes thymomas, carcinomas, cysts, lipomas, and neuroendocrine tumors (NETs). Specifically, thymic malignancies are relatively rare, accounting for 0.13 cases per 100,000 population, with the majority of cases classified as thymomas.1 Thymomas should not be considered benign. Histopathologically, they are staged into four groups; stage I thymomas represent noninvasive tumors with an intact capsule, whereas stage III and IV correspond to tissue invasion (blood vessels or lung tissue) and lymph node involvement/distant metastasis, respectively.2 They represent 47% of anterior mediastinal tumors with a peak incidence between 35 and 70 years of age and with nearly equal sex predilection.2,3 A wide spectrum of diseases is associated with thymomas, including myasthenia gravis, which occurs in 30% to 50% of patients.4 Further associated paraneoplastic syndromes include pure red aplasia, seen in 5% of patients, and hypogammaglobulinemia, seen in 10% of patients.5 Grossly, early-stage thymomas appear as smooth round or oval masses but in advanced stages, calcifications and irregular margins will be present. NETs are the least common thymic malignancy, with presentation after the fifth decade of life and predominantly in men.6 Since being first described in 1972 by Rosai and Higa,7 approximately 150 cases of thymic NETs have been reported in the literature, with atypical pathologic characteristics representing a minority subset.