Minute (<5 mm) and small (5-10 mm) rectal
carcinoids discovered during colonoscopy are generally considered to be non-aggressive, and the management and surveillance of patients with this entity are usually limited. We present the case of a 61-year-old Chinese female with multiple sub-5 mm
carcinoid tumours in the rectum without any computed tomography (CT) evidence of lymph node or distant
metastases. She underwent an ultra-low anterior resection for a sessile rectal
polyp with the histological appearance of a moderately differentiated
adenocarcinoma. Seven foci of minute
carcinoids in the rectum and perirectal lymph node metastastic spread from the
carcinoid tumours were also discovered on histopathology. There were no
lymph node metastases originating from
adenocarcinoma. This case report and review of the literature suggests that minute rectal
carcinoids are at risk of metastasizing and that these patients should be investigated for lymph node and distant metastatic spread with CT and
somatostatin receptor scintigraphy or its equivalent, as this would influence prognosis and surgical management of these patients. Findings relating to lymphovascular invasion, perineural invasion, high Ki-67, mitotic rate, depth of tumour invasion, central ulceration, multifocal tumours and size are useful in predicting
metastases and may be used in scoring tools. Size alone is not a good predictor of metastastic spread.