Unusual Location of a Giant Cell Tumour.

Giant cell tumours (GCT) are rare aggressive non-cancerous tumours which usually affect the long bones. We describe a case of GCT of the first rib in a young woman without a relevant history. The patient presented a left cervico-thoracic mass which was biopsied in our department (CT-guided biopsy). She was referred to the thoracic surgery department after histological results. LEARNING POINTS: Giant cell tumours (CGT) are benign tumours that usually occur on long bones with costal localization being a rare entity.Ultrasound can be a useful tool to assess the nature of the lesion.Diagnosis is based on lesion biopsy, but aggressive surgical resection can be performed.CGT should be considered in the differential diagnosis of costal tumours. © EFIM 2021.