<prompt> Which of the following is a retention cyst?Sebaceous cystSpermatoceleDermoid cystPancreatic cyst  <response>: Ans. b Spermatocele. Ref. Bailey and Love, 25th1383SPERMATOCELE is unilocular retention cyst, derived from epidydymis.CLASSIFICATION OF CYSTSA. Congenital Persistence of normal vestigial remnants1. Nuchal, thyroglossal, branchial.2. Ectopia of various tissues3. Failure of continuation of tubular element.4. Hamartomas5. Hydatid of morgagni6. Dermoid, epidermoid, enterogenous7. PCKD8. Cystic hygroma, omental cystB. Acquired1. Mucus retention cyst3. Parasitic5. Degenerative7. Apoplectic not a true cyst9. Pseudocyst11. Epidermoidsebaceous13. Mammary dysplasia15. Hematogenous cyst17. Cystadenoma, cystic teratoma2. Implantation cyst4. Hyperplastic6. Traumatic8. Neoplastic10. Spermatocele, Retention cyst of mouth12. Hydatid, trichinosis14. Uterine leiomyoma16. Pituitary18. Pancreas 