ABSTRACT
A 10-year-old boy with congenital immunodeficiency (X-linked agammaglobulinaemia) presented with loss of appetite and weight, right-sided abdominal pain, diarrhoea and low-grade fever. Radiological investigations with barium follow-through, CT, PET and octreotide scans revealed a primary caecal/ascending proximal colonic mass with liver and bony metastases. Urine screen for 5HIAA was positive. Percutaneous liver biopsy confirmed the diagnosis of neuroendocrine carcinoma. The radiological work-up and the usefulness of various imaging modalities in the diagnosis of this rare paediatric tumour are discussed. The PET scan demonstrated the primary tumour and the metastatic locations more vividly than the octreotide scan, which is currently considered to be the most specific imaging modality for neuroendocrine masses.
