LARGE-CELL NEUROENDOCRINE CARCINOMA OF THE THYMUS

Aim: We highlight the occurrence of an unusual neuroendocrine tumour, a large cell neuroendocrine carcinoma, arising from the thymus. Case d etails: A 68-year-old man with a history of cigarette smoking had a la rge mediastinal tumour arising from the thymus removed, Two years late r the tumour recurred; it was debulked surgically but the patient died 2 months later, Histological examination of both tumour specimens rev ealed a tumour with an endocrine pattern, composed of large pleomorphi c cells with large nuclei and prominent nucleoli, The mitotic count ra nged from 19 to 26 per 10 high-power fields and large tracks of coagul ative tumour necrosis were present, The tumour cells were strongly pos itive for neuron-specific enolase (NSE), chromogranin, CAM5.2 and AE1/ 3, with cytoplasmic dot-like accentuation for the latter three markers , The tumour fulfilled the criteria for a diagnosis of large cell neur oendocrine carcinoma. Conclusions: Large cell neuroendocrine carcinoma should be distinguished from atypical carcinoid and small cell carcin oma, It is a distinctive neuroendocrine malignancy with a prognosis be tween that of atypical carcinoid and small cell carcinoma, and needs t o be treated aggressively.