Neuroendocrine tumours are a rare tumour type involving neuroectodermal cells. They are also termed carcinoids. Gastroenteropancreatic system is most commonly involved. They are classified as low, intermediate or high grade depending upon mitotic index and Ki-67 index. Their diagnosis involves measurement of chromogranin A levels. Ultrasound is the initial imaging modality for their evaluation. Endoscopic ultrasound allows close evaluation of the tumour. Staging is commonly undertaken by computed tomography scan. These tumours typically show hyper-enhancement on arterial phase. Their metastasis to the liver also shows arterial enhancement. Small bowel carcinoids tend to have hepatic and mesenteric spread. Mesenteric spread of disease gives a characteristic spoke wheel appearance. On magnetic resonance imaging, these tumours typically appear as hypointense on T1 weighted image, hyperintense on T2 weighted image and show avid enhancement on postcontrast scan. Surgical resection is appropriate treatment with follow-up at 6-month intervals during the first year. The current review was planned to cover the aetiology, diagnosis, staging, imaging techniques, imaging features and treatment of these rare tumours that need prompt diagnosis.
Keywords: Neuroendocrine tumours, Carcinoid tumour, Carcinoid..