[Case of thymic carcinoid associated with multiple endocrine neoplasia type I treated effectively with chemotherapy].

A 53-year-old man was referred to our hospital due to a mediastinal mass found during a medical checkup in July 2009. He had a past history of hyperparathyroidism, for which he underwent surgery in 1994, and also had a family history in that his sister had multiple endocrine neoplasia type 1 (MEN1). He was given a diagnosis of MEN I on genetic testing. Chest CT revealed a mediastinal mass 4 cm in maximum dimension, and an atypical carcinoid was diagnosed according to mediastinal biopsy findings. Bone metastasis was detected and he was given cisplatin and etoposide. The tumor decreased in size by 30%, and was evaluated as showing partial response. Although there are some cases of MEN-related thymoma treated by surgery, a case which successfully responded to chemotherapy alone is thought to be extremely rare.