Thoracic venous malformation: a particular form of a visceral variant.

A teenage boy was admitted due to a thoracic mass with previous respiratory infections. The CT scan showed phleboliths in a cystic lesion with large draining channels. He also presented a mild thrombocytosis, elevated fibrinogen and D-dimer. Arteriogram revealed no abnormal arterial supply but venography proved venous draining channels as the major components of the lesion. The most important venous pedicle was embolised. However, 6 months later, CT scan showed no reduction in lesion size. Surgical resection was performed. Anatomopathological study described a venous malformation (VM) with a lymphatic component, and genetic testing found a typical mutation in PIK3CA and genetic variant in MAP3K3 This case reports a very rare pattern of thoracic vascular tumour. The authors aim to highlight the importance of genetic studies of VM with atypical presentation in order to achieve a definitive diagnosis.