Carcinoid tumour of the thymus with systemic manifestations: a radiological and pathological study.

, , 553-558. Following recent reports of an unusual mediastinal tumour described as `mediastinal endocrine neoplasm of probable thymic origin, related to carcinoid tumour' (Rosai and Higa, 1972), a further case, in a 72-year-old man, has been studied. Polyarthropathy was the presenting feature, and the patient also had clubbing of the fingers and clinical evidence of a probable proximal myopathy and a peripheral neuropathy. These non-metastatic systemic manifestations have not previously been described with this type of tumour. By retrograde thymic venography the tumour was conclusively shown to be arising in the thymus, as had been suspected but not proven in previously described cases. Histologically the typical picture, including areas of cells with true rosette formation and cells with argyrophil granules, was seen. In contrast to the more usual thymic tumours, this type of neoplasm responds poorly to radiotherapy, but surgical treatment may give good results. Therefore, in a situation where the possibility of carcinoid tumour of the thymus exists, it is imperative that tissue be obtained for histological diagnosis before any therapeutic decision is made.