This case shows a posterior paralabral cyst extends to the spinoglenoid notch with subsequent suprascapular nerve entrapment that is suspected indirectly by acute denervation of the infraspinatus muscle. The cyst is seen connecting to a focal posterior labral tear/detachment suspected to be the source of this cyst. The secondary involvement of the spinoglenoid notch by a paralabral cyst differs from the primary spinoglenoid notch cyst that is a ganglion cyst.
In this case, the suprascapular notch is normal. If compressed, both supraspinatus and infraspinatus muscles will be denervated.