Metastatic Neuroendocrine Tumour in a Renal Transplant Recipient: Dual-Tracer PET-CT with (18)F-FDG and (68)Ga-DOTANOC in This Rare Setting.

Recipients of renal transplant are at increased risk of developing various malignancies, especially post-transplant lymphoproliferative disorder (PTLD) and skin cancers. Neuroendocrine tumours (NET) of the gastrointestinal tract have not been reported in this setting. Here we describe the case of a 75-year-old male who had undergone renal transplant 8 years back and now presented with significant weight loss and backache, clinically suspected as PTLD. (18)F-Fluordeoxyglucose ((18)F-FDG) positron emission tomography-computed tomography (PET-CT) showed hypermetabolic lesions in the liver and rectum, raising the suspicion of PTLD. However, biopsy from the liver lesion showed poorly differentiated NET. (68)Ga-labelled [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid]-1-NaI(3)-octreotide ((68)Ga-DOTANOC) PET-CT was then done, which confirmed the primary lesion in the rectum with liver metastases.