%0 Journal Article %T Primary Carcinoid Tumour of the Kidney: A Review of the Literature %A Ayodeji O. Omiyale %A Anthony Kodzo-Grey Venyo %J Advances in Urology %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/579396 %X Context. Primary renal carcinoid tumours are rare. Their pathogenesis is unknown and the clinical presentation is similar to other renal tumours thus posing diagnostic dilemmas for clinicians. Objectives. To review the literature for case reports of primary renal carcinoids. Methods. Literature was extensively searched for case reports for primary renal carcinoids. Reports of metastatic carcinoids to the kidneys were excluded. Results. Approximately less than 90 cases of primary carcinoid tumours of the kidney have been reported in the literature. A total of 29 cases of primary renal carcinoids were reviewed. The mean age of presentation was 48 years (range 29¨C75) with both right kidney (48.3%) and left kidney (44.8%) being equally affected. 28.6% of the cases reviewed were diagnosed as an incidental finding. The mean followup time was 20 months with 73.1% of patients without evidence of disease after surgical treatment (radical or partial nephrectomy). Primary carcinoid tumours of the kidney are often well differentiated tumours. They are often misdiagnosed because of their rarity and similar presentation with other renal tumours. Conclusions. Primary carcinoid tumours of the kidney are rare tumours with an indolent course with frequent metastasis. Metastatic work up and followup is required in their management. 1. Introduction The histology of carcinoid tumours was first described by Lubarsch in 1888 [1], while the first case of carcinoid in the gastrointestinal tract was reported by Oberndorfer in 1907 [2]. Carcinoid tumours are neoplasms with neuroendocrine differentiation. They are thought to arise from APUD cells with characteristic secretory granules. Although they have certain clinicopathological features which are specific to the organ in which they arise, there are several features common to neuroendocrine tumours (NETs) regardless of the site of origin in the body [3]. There are various systems of nomenclature in the classification of NETs which has led to confusing terminologies. Some of which differ in the use of terminologies and criteria for staging and grading [4]. Attempts have been made to ensure a single, uniform, and reproducible system of nomenclature. Klimstra et al. in a review of the nomenclature, staging and grading systems in the pathologic classification of NETs however suggested that in all the systems a sharp distinction is made between well differentiated and poorly differentiated with the latter clearly described as high grade neuroendocrine cancers [3]. WHO in 2010 classified neuroendocrine neoplasms into NET-well %U http://www.hindawi.com/journals/au/2013/579396/