A cyst of Nuck or hydrocele of Nuck, also called the forgotten diagnosis, [1] is a rare anatomical anomaly in women. Because of its rarity it is often misdiagnosedand due to the treatment pittfalls itis important to properly diagnose this tumour. Clinical examination and imaging must be performed to differentiate and diagnose the cyst correctly. However, even these modalities are not specific enough as we present in this case of a 28 year old woman with a suspected abscess of Nuck that was shown to be a cyst of Bartholin by histopathological examination. Furthermore, we reviewed the literature on this subject.