Histological evaluation of the testicular nubbins in patients with nonpalpable testis: assessment of etiology and surgical approach.

There is a controversy in the literature whether testicular nubbins carry malignancy risk and excision of the nubbin is necessary in patients with nonpalpable testis. It is also controversial whether vanishing testis has the same etiopathogenesis and risk with true undescended testis. The aim of this study is to investigate the histological findings of testicular nubbins in patients with nonpalpable testis and to question etiology and surgical indications for vanishing testis. We reviewed the histopathological results of 44 testicular nubbins in 40 patients (mean age: 4.1 years, range 1-13 years) with nonpalpable testis between 1992 and 2004, retrospectively. Exploration revealed 5 intraabdominal and 39 inguinal testicular nubbins. Of 44 specimens only 5 (11.3%) from inquinal testicular nubbins were found to have seminiferous tubules. Two of the five had seminiferous tubule structures with viable germ cells showing maturation correlating with age. The other two with scarce seminiferous tubules were seen on only a single area and one had Sertoli cells only. None of the excised tissue had malignant degeneration. The vas deferens was identified in 23 (52.2%), vessels in 26 (59%), calcification in 14 (31.8%) and hemosiderin in 12 (27.2%) of excised tissue. Presence of calcification in one-third of the nubbins supports vascular accident thesis in the etiopathogenesis of vanishing testis. The possibility for the presence of seminiferous tubules and viable germ cells in the testicular nubbin is low. These facts decrease theoritical risk of malingnancy. Therefore, an inguinal exploration for testicular nubbin in patients with vas deferens and vessels entering into the inquinal canal diagnosed at laparoscopy can be postponed untill testicular prosthesis implantation and the nubbin can be removed at this operation.