Which condition is described as a nontender, fluid-filled scrotal mass overlying the testis and spermatic cord?

The condition characterized by a nontender, fluid-filled scrotal mass over the testis and spermatic cord is known as a hydrocele. It occurs when there is an accumulation of fluid in the tunica vaginalis, which is the pouch of serous membrane surrounding each testis. Hydroceles are typically painless and feel smooth and fluctuant upon examination.

The distinguishing feature of a hydrocele is that it results from an imbalance in the production and absorption of fluid, often resolving spontaneously in infants. When assessing a scrotal mass, the non-tender nature and the fact that it is fluid-filled are key indicators that point towards a hydrocele rather than other conditions like hernias, which can present with a palpable bulge and possibly tenderness; varicoceles, which are dilated veins of the spermatic cord and often described as a "bag of worms" due to their appearance; or orchitis, which is usually accompanied by pain and inflammation of the testis. These contrasting symptoms and characteristics help in making an accurate diagnosis, reinforcing the significance of understanding hydroceles in the context of neonatal care.