1. Dermoid and Epidermoid
1.1. 1. pathogeneisis
1.1.1. 1. epithelial debris in midline during closure of mandible
1.2. 2. clinically
1.2.1. 1. young adult
1.2.2. 2. no sex predilection
1.2.3. 3. anterior part of floor of mouth, submandiblar and sublingual
1.2.4. 4. appearance
1.2.4.1. 1. above mylohyoid causes bulge in floor of mouth causing elevation of tongue and difficulty eating and drinking
1.2.4.2. 2. when deeper between geniohyoid and mylohyoid causes submental bulge
1.2.4.3. 3. cyst is painless slow growing
1.2.4.4. 4. size 2cm to more
1.2.4.5. 5. consistency is soft fluctuant
1.2.4.6. 6. pale yellowish pink color is noted beneath thinned epithelium
1.2.4.7. 7. may have doughy consistency on palpation
1.3. 3. histo
1.3.1. 1. ct wall lined by thin kera st epith.
1.3.2. 2. lumen filled with keratin (epidermoid)
1.3.3. 3. other cases may have sebacceous gland, hair follicle and teeth (Dermoid) as cells are totipotent
1.4. 4. treatment
1.4.1. 1. surgical removal
2. thyroglossal
2.1. 1. frequency
2.1.1. 1. most common dev cyst of neck (75%)
2.2. 2. etiology
2.2.1. 1. in 4th week IU at foramen cecum thyroid develop by downward growth of epithelium thorugh base of tongue to midline of neck
2.2.2. 2. at 10th week IU tract breaks up but residual epithelial elements may perisist and proliferate to form a cyst
2.3. 3. clinically
2.3.1. 1. in young patients
2.3.2. 2. appearance slowly growing asymptomatic firm cystic midline mass vary from few mm to several cm
2.3.3. 3. site:
2.3.3.1. 1. anywhere along thyroglossal tract may occur in floor of mouth
2.3.3.2. 2. 2% of lesion within tongue near foramen cecum
2.3.3.3. 3. if large causes dysphasia or interfere with eating and speech
2.3.3.4. 4. when attached to hyoid bone and tongue they move when swallowing
2.3.3.5. 5. if cyst becomes infected (sinus tract may occur)
2.3.3.6. 6. small opening on skin or mucosal surface may be seen
2.4. 4. histopathologic features
2.4.1. 1. cyst lining varies depending upon its location above level of hyoid ( st sq epithelium
2.4.2. 2. below it is ciliated or columnar
2.4.3. 3. c.t wall may contain small areas of thyroid tissue, lymphoid tissue and mucous gland
2.5. 5. treatment
2.5.1. 1. complete surgical excision
3. Benign cervical lympho epithelial (branchial cleft, benign cystic lymph node)
3.1. 1. Location
3.1.1. 1. located on lateral aspect of neck, anterior to sternomastoid muscle
3.2. 2. etiology
3.2.1. 1. origin of cyst is from remnants of epithelial cells of Branchial Grooves
3.2.2. 2. alternative theory of origin is cystic transformation of cervical sinus epithelium entrapped in cervical lymph node
3.3. 3. clinically
3.3.1. 1. age : child and adult
3.3.2. 2. appearance
3.3.2.1. 1. asymptomatic movable mass on lateral aspect of neck close to anterior borer of sternomastoid muscle
3.3.2.2. 2. slowly growing if infectd abscess and draining sinus may occur
3.3.2.3. 3. cyst occur at angle of mandible submandibular and parotid area
3.4. 4. histopathology
3.4.1. 1. cyst lined by st sq epithelium
3.4.2. 2. wall of cyst is lympoid tissue with lymph node pattern
3.4.3. 3. shows well formed germinal center
3.4.4. 4. contain watery fluid or thick gelatinous mucoid material
3.5. 5. treatment
3.5.1. 1. surgical esxision
4. Mucous Extravasation Cyst (Mucocele)
4.1. 1. Etiology
4.1.1. 1. due to trauma to minor salivary gland excretory duct
4.1.2. 2. example biting on lip or cheek
4.1.3. 3. result in pooling of mucous to surrounding c.t
4.1.4. 4. pool of extravasated mucous induce inflammation
4.1.5. 5. inflammation consist of PMNLs , Leukocytes, Granulation tissue forming wall around mucin pool
4.1.6. 6. this gives pseudocyst appearance
4.2. 2. clinical Features
4.2.1. 1. age
4.2.1.1. 1. children and adults
4.2.2. 2. site
4.2.2.1. 1. lower lip then buccal mucosa then ventral surface of tongue, floor of mouth
4.2.3. 3. appearance
4.2.3.1. 1. superficial lesion are painless with smooth surface with bluish hue or translucency
4.2.3.2. 2. deep ones appear as diffuse swelling with no translucent blue hue
4.2.3.3. 3. range from mm to cms
4.2.3.4. 4. if aspiration is attempted decrease in size occurs
4.2.3.5. 5. fluctuation in size due to englufing of inf. cells and further mucous release
4.3. 3. histopathologic
4.3.1. 1. cavity with pooled mucin
4.3.2. 2. epithelium is thinned and seperated from mucin pool by compressed granulation tissue
4.3.3. 3. mucin pool is surrounded by fibrous and granulation tissue
4.3.4. 4. infiltrated by large no of neutrophils, macrophages, lymphocytes, and plasma cells
4.3.5. 5. adjacent slaivary gland show acinic degeneration and ductal dilatation
4.4. 4. treatment
4.4.1. 1. surgical excision