Paratesticular seminoma: echographic features and histological diagnosis with review of the literature.

Primary extratesticular seminomas exceptionally occur in the epididymis or in the paratesticular region/spermatic cord. Some old papers included poor histological description or insufficient photographic documentation, reducing the number of faithful cases: an up-to-date systematic review is lacking. We report the 4th primary seminoma of the paratesticular region/spermatic cord in a 35-year-old man, including the first echographic description. We provide review of the literature and etiopathogenetic discussion. Ultrasound examination showed a right paratesticular, solid, heterogeneous mass (iso-hypoechoic with hyperechoic striae; peri- and intra-lesional vascular signals) with no testicular involvement: the paratesticular origin was confirmed by pathological examination. Despite careful gross examination and extensive sampling, the 6.5-cm extratesticular tumor revealed only one microscopic focus with minimal invasion (<2 mm) of the atrophic testicular parenchyma. Intratubular germ cell neoplasia or morphologic features of a regressed testicular tumor (fibrosis/scar, necrosis, hyalinization, calcification, inflammation) were not found. Primary seminomas of the paratesticular region/spermatic cord occurred at an older mean age and presented as bigger lesions if compared to the 9 primary epididymal seminomas reported in literature. Clinical-pathological correlation and accurate sampling are mandatory for a correct diagnosis.