reactive hydrocele

Hydrocele if fluid collection alonf the spermatic cord. They may represent persistent developmental connection along the spermatic cord or an imbalance of fluid production. They can even occur in the canal of nuck in females, but this is extremely rare. Hydroceles express little risk that would have clinical consequence, but then again it depends on particular case. Reactive hydrocele is often present in cases of testis torsion, for example the extent of reactive hydrocele is a marker of torsion. Reactive hydrocele, for example, also helps in visualization of the point of spiral twist as reactive hydrocele is surrounded by the fluid all around and then again, the reactive hydrocele itself is a sign of torsion.
There is also interesting conclusion, concerning reactive hydrocele, that it may accompany testicular cancer, that is why if reactive hydrocele present, the scrotum should be transilluminated.

Mabry has given you good information on reactive hydrocele.

You could also do an internet search for the term or seek it out on wikipedia.org.

Good luck.