Primary Renal Carcinoid: Two Rare Cases at a Single Center

Abstract

Renal carcinoid tumors are exceedingly rare. These neuroendocrine masses are most frequently found in the gastrointestinal and respiratory tracts. A renal carcinoid tumor has only been documented in around 100 cases. In this article, we report two additional cases in female patients ages 53 and 63. Both tumors were found incidentally on computed tomography scans. Both women underwent radical nephrectomies. Neither has shown evidence of metastasis nor relapse to date; however, the 63-year-old woman was lost to follow-up. In conclusion, upon discovery of the asymptomatic renal mass, renal carcinoid should be a consideration in the differentiation, and if suspected, may be treated with radical nephrectomy as was done in our hospital.

Primary renal neuroendocrine neoplasms: A systematic literature review, report of four local cases, and original survival analysis of 63 patients from a national registry 2012–2018

“…Forty‐eight studies were included in our final analysis (Figure 1). These included six registry studies 1,2,6–9 20 analyses of previously published cases, 10–29 and 22 case series 30–51 . The paucity of large cohort or population studies yielded by our literature search is a testament to the extreme rarity of renal NENs.…”

“…This, however, appears to be a relatively infrequent occurrence in renal NEN 16,20,27,30,40 occurring only in 12.7%–13.6% of cases 16,20 . Instead, renal NEN commonly present as an incidental finding on cross‐sectional imaging 31,32,37,39,48 with rates of asymptomatic cases ranging from 25% to 36.4% and reaching as much as 80% in an 11 patient case series 31 . In symptomatic patients, abdominal pain is the most common presenting symptom, followed by haematuria, abdominal mass, and constitutional symptoms such as weight loss and fever 1,11–14,16,17,24,27,30–33,37–46,48,49 .…”

“…Instead, renal NEN commonly present as an incidental finding on cross‐sectional imaging 31,32,37,39,48 with rates of asymptomatic cases ranging from 25% to 36.4% and reaching as much as 80% in an 11 patient case series 31 . In symptomatic patients, abdominal pain is the most common presenting symptom, followed by haematuria, abdominal mass, and constitutional symptoms such as weight loss and fever 1,11–14,16,17,24,27,30–33,37–46,48,49 . Renal carcinoids are often solid tumour and have no characteristic features to differentiate them from other renal primaries; however, one of the most common radiological findings is calcification, which has been reported in 26.5%–30% of cases 16,20 …”

“…31 In symptomatic patients, abdominal pain is the most common presenting symptom, followed by haematuria, abdominal mass, and constitutional symptoms such as weight loss and fever. 1,[11][12][13][14]16,17,24,27,[30][31][32][33][37][38][39][40][41][42][43][44][45][46]48,49 Although multiple other series have also noted an increased incidence of renal NEN in the right kidney some with higher proportions than others, 14,21,32,35,36 there are several included studies reporting relatively similar rates in each kidney. 12,18,31,32…”