Expression analysis of the pluripotency marker UTF-1 for determining the applicability of testis-sparing surgery for prepubertal testis tumors

Surgical management of prepubertal testicular tumors: A 30-year study in our institution

OBJECTIVES

The 2021 European Association of Urology-European Society for Paediatric Urology guidelines on Pediatric Urology recommended testis-sparing surgery (TSS) as the primary approach to treat prepubertal testicular tumors exhibiting favorable preoperative ultrasound diagnoses. However, prepubertal testicular tumors are rare and clinical data regarding them is limited. Here, we analyzed the surgical management of prepubertal testicular tumors based on cases observed over approximately 30 years.

METHODS

Data were retrospectively reviewed from medical records of consecutive patients aged <14 years with testicular tumors who received treatment at our institution between 1987 and 2020. We compared patients by their clinical characteristics, namely, those who underwent TSS versus radical orchiectomy (RO) and those who received surgery in 2005 onward versus prior to 2005.

RESULTS

We identified 17 patients, with a median age at surgery of 3.2 years (range 0.6-14.0) and a median tumor size of 15 mm (range 6-67). The tumor size was significantly smaller in patients who underwent TSS than in those who underwent RO (p = 0.007). Patients treated in 2005 onward were more likely to undergo TSS than those treated prior to 2005 (71% vs. 10%, respectively), without significant differences in tumor size or the rate of preoperative ultrasound. No TSS cases required conversion to RO.

CONCLUSIONS

Recent improvements in ultrasound imaging technology allow for more accurate clinical diagnosis. Therefore, the indications of TSS for prepubertal testicular tumors can be judged based not only on the tumor size but also on the diagnosis of benign tumors by preoperative ultrasound.

Genetic and histopathological analysis of transverse testicular ectopia without persistent Müllerian duct syndrome: two case reports

Background

Transverse testicular ectopia (TTE) is a rare anomaly in which both testes descend through a single inguinal canal into the same hemiscrotum. Although almost 20–50% of patients with TTE exhibit persistent Müllerian duct syndrome (PMDS) and many genetic analyses have been performed, no reports have described the genes contributing to TTE without PMDS. Here, we report two cases of TTE without PMDS using immunohistochemical staining and genetic analysis.

Case presentation

Two Asian patients with TTE without PMDS were subjected to orchiopexy. We performed testicular biopsies during operation and obtained blood samples before the operation. Testicular tissues were stained for c-kit, placental alkaline phosphatase (PLAP), and undifferentiated embryonic cell transcription factor 1 (UTF1) to evaluate the presence of intratubular malignant germ cells. Additionally, we performed polymerase chain reaction-based direct sequencing to identify single nucleotide polymorphisms in genes associated with regression of the Müllerian duct and testicular descent (that is, anti-Müllerian hormone [AMH], AMH receptor 2 [AMHR2], insulin-like 3 [INSL3], and relaxin family peptide receptor 2 [RXFP2]). The three-dimensional structures of proteins were predicted using SWISS-MODEL. In immunohistochemical analysis, c-kit and UTF1 were positive, whereas PLAP was negative in three testicular tissue samples from the two patients. These features were also detected on the unaffected side. In variant analysis, common missense variants in the AMH gene (g.365G>T; c.165G>T; p.Ser49Ile [rs10407022]) were observed. All variants in INSL3 and RXFP2 genes were intronic or silent.

Conclusions

Because UTF1, a specific marker of spermatogonial stem cell activity, was expressed in both the affected and unaffected sides in the testicular tissues of two patients, the risk of malignancy may be high in these patients. Although the etiology of TTE without PMDS remains unclear, our variant analysis results were consistent with previous reports, and variants in the AMH gene (rs10407022) may contribute to the specific phenotype of TTE without PMDS.