This case report is on a 30-year-old male presented with Cushing syndrome and acute psychosis. The test was confirmed that he had got ectopic Cushing’s. CT chest showed anterior mediastinum mass measuring 4.5×8.3×8.6 cm and there were solid cavity nodules scattered in both lungs. Sputum culture was Nocardia farcinica and pathological reported from TTNB was well differentiate neuroendocrine tumor. Tc-99m Hynic TOC uptake of anterior mediastinum mass but faint radiotracer uptake on both lungs. He was treated by open sternotomy with tumor removal and received co- trimoxazole for treatment pulmonary nocardia. Pathological reported high grade neuroendocrine carcinoma of thymic neoplasm in origin, mitotic count more than 10 mitoses/m², Ki67 positive 50-60% and close margin. IHC show positive CD 117, chromogranin A, synaptophysin, CD56 and ACTH. He was diagnosed with thymic large cell neuroendocrine carcinoma. Follow up CT chest revealed no residual tumors and multiple cavities nodules in both lungs were almost resolved. Tc99m Hynic TOC showed no any current abnormal uptake. Multidisciplinary team decided to treat him with concurrent chemo radiation. About 9 months later, he had got hemoptysis and ACTH was rising again. CT chest showed new multiple nodules scattering in both lungs and anterior mediastinum mass was 1.6×3.7 cm. He was treated by rechallenged chemotherapy (Cisplatin and Etoposide). Follow up after 4 cycles, his clinical was improved and ACTH level decreased. Overall CT chest was stable disease by RECIST1.1. Follow up CT chest after complete 6 cycles of chemotherapy was stable disease. After break chemotherapy for 3 months, CT chest revealed multiple lung nodules were mildly increased in size but he had no symptoms and ACTH level still not increased.
Thymic large cell neuroendocrine carcinoma is a rare, aggressive tumor and poor prognosis.The patients can present with paraneoplatic symptoms related to abnormal hormones productivity by the tumor such as adrenocorticotropic hormone (ACTH) with Cushing syndrome. From the lack of standard treatment protocol and limited literature reviews make it difficult to treat. Complete surgical resection with or without chemotherapy and radiation seem to have better outcome.