Plastics

Question 1

Dermoid cyst

Answer 1

Dermoid cyst - encapsulated cystic space, lined by stratified squamous epithelium with keratinization. Keratin debris = “cheesy material.”
CONTAINS ADNEXAL STRUCTURES (sebaceous glands/sweat glands, hair follicles)… unlike epidermoid cyst
Usually superotemporal near orbital rim of frontozygomatic suture. (trapping of surface ectoderm along bony suture lines during development)
Cyst rupture –> granulomatous rxn (DDx cellulitis)

Question 2

Epidermoid cyst

Answer 2

Similar to dermoid cyst but NO adnexal structures (hair follicles and sebaceous glands/sweat glands)

Question 3

Adenoid cystic carcinoma (ACC)

Answer 3

MC lacrimal gland tumor. Associated with A LOT OF PAIN. ID factor - swiss cheese pattern on pathology

Question 4

Pyogenic granuloma

Answer 4

reddish conjunctival masses s/p prior ocular surgery or FB. Misnomer as no pus in lesions and no granulomatous inflammation

Question 5

Adnoid cystic carcinoma

Answer 5

purple “swiss cheese” or “cribiform” pattern = hallmark.
Highly malignant tumor usually occurs in women
(peomorphic adenoma usually occurs in men and is PAINLESS)
produces significant pain (2/2 invasion of orbital nerves), is associated with a poor Px.
Rx: exenteration is typically recommended with removal of adjacent bone.

Question 6

Dermal nevus

Answer 6

• Melanocytic nesting UNDER the epithelial surface of the eyelid
• only in the subepithelial area in the dermal nevi
• once mealnocytes LOSE their cxn to the JUNCTION and drop down into the subepithelial area, they essentially LOSE THEIR malignant potential.
• sometimes in dermal nevi, one may observe that the melanocytes adopt a neuroid appearance, and there is a clear area of no melanocytic nesting between the epithelium and subepithelial area.

Question 7

Junctional nevus

Answer 7

melanocytes are located at the epidermal-dermal junction in junctional nevi

Question 8

Compound nevi

Answer 8

melanocytes at the junction/subepithelial space

Question 9

Basal cell carcinoma

Answer 9

tumors orginate from the basal layer of the epidermis, and the cells are relatively monotonus (high nuclear-to-cytoplasm ratio)
cells form nests within the stroma with PALISADING of the nuclei peripherally within the nest.

MC = lower eyelid but more aggressive tumors are those of the medial canthus (tend to be deeply invasive and can extend into the orbit)

Question 10

Pleomorphic adenoma

Answer 10

• BENIGN epithelial tumor of the lacrimal gland
• path: epithelial/stromal structures with “nests” and “tubules” representing the epithelial component

tumors grow slowly in the lacrimal fossa –> characteristic excavation (not erosion) of the adjacent bone.

DO NOT do incisional biopsy (b/c significant recurrence if tumor left over –> then very difficult to remove)

Complete excision with a rim of surrounding normal orbital tissue.