12. Discussion
Also called Epidermal cyst.
Dermoid cyst of head & neck rare (6.9% of all dermoid cyst)
Orbit 49.5%,
nose 12.6%,
submental & submaxillary region 23.3 %
remainder 14.6%
Initially Based on pathogenesis & microscopic appearance
Congenital dermoid - teratoma type(ovaries & testes)
Acquired dermoid cyst (hands & other exposed parts)
Congenital inclusion dermoid (head & neck).
a.nasooptic groove
b.nose (frontonasal plate)
c.submental & submaxillary region
d.miscellaneous group(midventral or middorsal line )
13. Discussion
Now 4 types of Dermoid – Sequestration dermoid
Implantation dermoid
Tubulo dermoid
Teratomatous dermoid
Sequestration – inclusion of epithelium burried at line of
embryonic fusion eg; near head & neck
Implantation dermoid- indriven epithelium beneath skin due
to puncture injury eg ; exposed part of body
Tubulodermoid – cyst from unobliterated portion of
congenital ectodermal duct or tube eg;thyroglossal
cyst,post anal cyst,ependymal cyst in brain
Teratomatoid dermoid – from totipotent cells eg; ovary,testis
14. Discussion
Parotid dermoid – rare entity
Clinicallydifficult to make diagnosis
Physical examnation – no characterstic findings
Isolated mass, near surface or within gland
Histologically –keratization of squamous epithelium,
a/w skin appendages – hair follicles,sweat glands,
sebaceous gland
Parotid dermoid relatively well encapsulated
Simple excision may recur so superficial
parotidectomy is advisable
15. Conclusion
Parotid extremely rare
Due to rarity & absence of pathognomonic findings ,
difficult to diagnose preoperatively
Must be differentiated from malignant tumors & other
cystic lesion
Recur after simple excision so superficial
parotidectomy is advisable
Editor's Notes
from pea size to present size over right parotid region.No h/o - Pain , Sudden increase in size ,Discharge,Deviated angle of mouth