[Morphologic and histopathologic analysis of testicular appendages].

Objective: To investigate the incidence of testicular appendages, observe their morphology, and analyze their histopathological origins.

Methods: We observed 67 testes in 54 patients (15 children and 39 adults) undergoing scrotal surgery, investigated the incidence of testicular appendages, and identified their histopathological origins. We used the Chi-square test to compare the findings from the children and adult patients, with P < 0.05 as statistically significant.

Results: The detection rates of the appendix testis, appendix epididymis, paradidymis, vas aberrans superior, and vas aberrans inferior were 80.6% (54/67), 23.9% (16/67), 1.5% (1/67), 3.0% (2/67), and 1.5% (1/67), respectively. The incidence of testicular appendages was higher in children than in adults (93.3% vs 80.8%), but with no statistically significant difference (Chi2 = 1.339, P > 0.05), and that of the appendix testis and epididymis with pedicles was significantly higher in the former than in the latter (82.4% vs 54.7%, chi2 = 4.149, P < 0.05). Pathological examination showed that the appendix testis originated from the paramesonephric duct, while the appendix epididymis, paradidymis, vas aberrans superior, and vas aberrans inferior from the mesonephric duct.

Conclusion: Testicular appendages consist of five embryonic remnants, including appendix testis, appendix epididymis, paradidymis, vas aberrans superior, and vas aber- rans inferior. The appendix testis originates from the paramesonephric duct, and the other four from the mesonephric duct. The clinical implication of these testicular appendages is their tendency to torsion.