The hydatid of Morgagni is a small embryological remnant at the upper pole of the testis. Torsion of the hydatid is of no consequence in itself except that it presents a similar picture to torsion of the testis which is a surgical emergency.
The pain from a torsion of the hydatid is usually less severe and has a longer history than for a torsion of the testis. Occasionally, the torted hydatid may be palpable or be visible through the scrotal wall on transillumination as a "blue dot" on the scrotum. Scrotal ultrasound may be able to delineate the enlarged appendage and a normal testis.
If in doubt, the scrotum should be explored to rule out testicular torsion and remove the infarcted hydatid.
Removal of the opposite appendage is not indicated.