Pulmonary atypical carcinoid in a patient with Cowden syndrome.

Cowden syndrome is a phosphatase and tensin homologue on chromosome ten (PTEN) hamartoma tumour syndrome. The loss of function of the PTEN protein is associated with the risk of development and progression of several types of tumours, such as pulmonary neuroendocrine tumours and carcinoids. We present a 65-year old male non-smoker, who was diagnosed with Cowden syndrome and had a pulmonary tumour. He underwent wedge resection via video-assisted thoracoscopic surgery and was histopathologically diagnosed with an atypical carcinoid. To our knowledge, this is the first report on a pulmonary atypical carcinoid in a patient with Cowden syndrome. The present findings suggest a potential link between phosphoinositide-3 kinase/protein kinase B signalling in Cowden syndrome and the development of pulmonary neuroendocrine tumours, such as carcinoids.