Primary neuroendocrine carcinoma of the thymus (formerly known as thymic carcinoids) are unusual tumors that account for 5% of all anterior mediastinal neoplasms. Thymic neuroendocrine carcinomas exhibit a much more aggressive behavior than those originating from other foregut locations and are associated with the ectopic ACTH syndrome in 38% of cases. Patients having a thymic neuroendocrine carcinoma usually present with symptoms such as chest tightness, dyspnea, a palpable neck mass and sometimes a weight gain. We report on 2 patients with thymic neuroendocrine carcinoma who showed different clinical manifestations each other. One presented with a typical. Cushingoid appearance and the other had symptoms of fatigue and weight loss which is a common symptom of malignant tumors.