Retroperitoneal haemangioma masquerading as recurrence of well-differentiated neuroendocrine tumour: a cautionary note.

Gallium 68-DOTATATE positron emission tomography scanning is the cornerstone of nuclear medicine imaging for neuroendocrine tumours. Previous reports have demonstrated the potential for vertebral haemangiomata to mimic neuroendocrine skeletal metastases. We present the case of a 42-year-old man with a history of well-differentiated neuroendocrine tumour of the appendix, identified incidentally following emergency appendicectomy. Postoperative 68Ga-DOTATATE positron emission tomography/computed tomography scanning revealed an intensely gallium-avid retroperitoneal lesion adjacent to the right psoas muscle. Surgical excision of this lesion was recommended following multidisciplinary team discussion. Histological evaluation of the resected lesion revealed an intravascular capillary haemangioma. Haemangiomas can mimic residual or recurrent neuroendocrine tumour based on gallium avidity, and this should be considered in atypical cases.