Testicular remnant "nubbin" and incidental ectopic adrenal cortical rests: A case series and systematic review

Abstract

Aim: To determine whether excising a testicular remnant or nubbin is necessary and perform a systematic review of the incidental ectopic adrenal cortical rest associated with undescended testis.

Material and methods: A retrospective analysis of impalpable undescended testis was carried out between May 2016 and June 2019. The demographic data, intra-operative findings and histopathological diagnosis were analyzed. In conjunction with this, systematic search of PUBMED and EMBASE database was performed by using the search terms "undescended testis" AND "ectopic adrenal tissue". Data was collected for demographic characteristics, size and appearance of ectopic adrenal cortical rest and histopathology. Quantitative data has been presented as medians. Categorical variables have been presented as percentages.

Result: We encountered 43 cases of impalpable undescended testis, out of which, nubbins were identified in 9 cases. Incidence of EACT in nubbin and impalpable UDT was 2/9 (22.22%) and 2/43 (4.7%) respectively. None of the excised nubbin had germ cells. On Systematic review, EACT associated with UDT was seen in 90/2501 (3.6%), while its association with testicular nubbin has been reported only once before in a case report.

Conclusion: A testicular nubbin is a condition wherein no viable testicular tissue can be grossly identified in a case of impalpable testis. Even when germ cells are not found in the excised nubbin, the presence of ectopic adrenal cortical rest make them prone to later malignant transformation. Association of EACT with UDT has been consistently reported but there is scarcity of such documentation in association with testicular nubbin.

Keywords: Ectopic adrenal cortical tissue (EACT); Impalpable UDT; Nubbin; Testicular remnant; Vanishing testis syndrome (VTS).