Eyelids

Question 1

What does the skin consist of

Answer 1

Epidermis, Dermis and Skin appendages

Question 2

How are cutaneous tumors classified

Answer 2

By their cell of origin as well as their location in the epidermis, dermis of skin appendage

Question 3

How are many layers are in the epidermis

Answer 3

Four

Question 4

What cells does the epidermis consist of?

Answer 4

Keratinocytes, Langerhan cells, Melanocytes and Merkel cells

Question 5

What are the layers of the epidermis and describe them

Answer 5

From superficial to deep:

Keratin (horny) layer - thin layer consisting of flat cells devoid of nuclei

Granular cell layer - one or 2 layers consisting of diamond shaped or flattened cells containing keratin hyaline granules

Stratum spinosum - 5 cell layers thick, polygonal in shape, have abundant eosinophilic cytoplasm. Free borders are joined by intercellular bridges (Desmosones) giving rise to the alternate name ‘prickle cell layer’

Basal cell layer - single row of columnar cells which give rise to more superficial cells. Contain melanin derived from adjacent melanocytes

Question 6

What does the dermis consist of?

Answer 6

Connective tissue, blood vessels, lymphatics, nerve fibres, macrophages, fibroblasts and mast cells

Question 7

How does the dermis and epidermis connect?

Answer 7

The upward dermal projections (papillae) interdigitate with the downward epidermal projections (rete ridges)

Question 8

Where does the dermis lie in the eyelid?

Answer 8

On top of the orbicularis oculi

Question 9

What are the skin appendages and where do they lie in the lid?

Answer 9

Adnexae

Lie deep in the dermis or within the tarsal plates

Question 10

What glands are in the dermis and describe them

Answer 10

Sebaceous glands: located in the caruncle and eyebrow hairs. Tiny sebaceous glands are associated with thin (vellus) hairs covering periocular skin

Meibomian glands: Modified sebaceous glands within the tarsal plate that empty through a single row of about 30 openings in each lid. Each gland consists of a central duct and multiple acini, the cells of which synthesize lipid (sebum) which enters the duct and makes up the outer layer of the precorneal tear film

Glands of Zeiss: Modified sebaceous glands associated with lash follicles

Gland of Moll: Modified apocrine sweat glands that either open into a lash follicle or directly onto the anterior lid margin between the lashes. They are more numerous in the lower lid.

Eccrine sweat gland: Distributed throughout the eyelid skin, not confined to the lid margin unlike Gland of Moll

Pilosebaceous unit: Hair follicles together with their sebaceous glands

Question 11

What is a macule

Answer 11

A localised area of colour change without elevation or infiltration. A macule may be pigmented (freckle), hypopigmented (vitiligo), or erythematous (capillary haemangioma)

Question 12

What is a papule

Answer 12

A small solid elevation of skin that is either flat topped or dome shaped

Question 13

What is a pustule

Answer 13

A collection of pus

Question 14

What is a vesicle

Answer 14

A small circumscribed lesion filled with fluid

Question 15

What is crust

Answer 15

Dried skin exudate

Question 16

What is a nodule

Answer 16

A solid area of raised skin

Question 17

What is a cyst

Answer 17

A nodule containing an epithelial lined cavity filled with fluid or semi solid material

Question 18

What is a plaque

Answer 18

A palpable shallow elevation of skin, usually more than 2cm in diameter

Question 19

What is scale

Answer 19

Thickening of the horny layer keratin in the form of readily detachable fragments

Question 20

What is a papilloma

Answer 20

A tag like projection from the skin surface

Question 21

What is an ulcer

Answer 21

A circumscribed lesion of skin loss extending from the epidermis into the dermis

Question 22

What is hyperkeratosis

Answer 22

Increase in the thickness of the keratin layer seen clinically as scaly skin. Can be a feature of both benign and malignant epithelial tumors

Question 23

What is acanthosis

Answer 23

Thickening of the squamous cell layer (stratum spinosum)

Question 24

What is dysplasia

Answer 24

Alteration in the size, morphology and organisation of cell structures. There is disturbance of normally structured and recognised layers of tissue e.g. loss of cell polarity

Question 25

What is dyskeratosis

Answer 25

Is keratinsation other than on the surface

Question 26

What is parakeratosis

Answer 26

Retention of nuclei into the keratin layer

Question 27

What are examples of carcinoma in situ?

Answer 27

Bowen’s disease

Intraepidermal carcinoma

Question 28

What is carcinoma in situ?

Answer 28

Exhibits dysplasia throughout the thickness of the epidermis and marked hyperkeratosis

Question 29

What are the characteristics of benign lid lesions

Answer 29

Lack of induration and ulceration
Uniform colour
Limited growth
Regular outline
Preservation of normal lid margin structures

Question 30

What type of biopsies may be used in suspected benign lesions

Answer 30

Shave/incisional biopsy - portion of the lesion removed for histology. Used in large superficial lesions e.g. seborrheic keratosis. In some cases the bulk of the lesion is removed and no further treatment is required provided it is proved to be benign

Excisional biopsy - used for small tumours and fulfils both diagnostic and treatment objectives

Question 31

What are the treatment options for benign lesions?

Answer 31

Excision - excision of the lesion and a small area of surrounding normal tissue

Marsupialization - removal of the top of the cyst allowing drainage and subsequent epithelialization

Other options: ablation, laser, cryotherapy