METABOLIC CHANGES AND DEGENERATION

OPTOM FASLU MUHAMMED

XANTHELASMA AND XANTHOMAS Elevated ,plaque like or nodular lesions often

multiple and bilateral In young, the disease is associated with

systemic hypercholesterolaemia and lipoproteinaemia

In adults, no underlying cause is noticed

Under microscope there is dermal infiltration of large foam cells, principally around vascular channels

Lesion tends to reoccur in young, if underlying cause is not rectified

AMYLOIDOSIS It is an amorphous eosinophilic homogenous

substance deposited in the stroma The amyloidosis of lid occurs in secondary form

following extraocular inflammation such as trachoma

Primary amyloidosis of lid is extremely uncommon

In certain cases there may be associated palpebral conjunctival amyloidosis

TUMOUROUS CONDITIONS

ACTINIC KERATOSIS• The lesions are secondary to exposure to sunlight• Elderly individuals are primarily affected• Face and eyelids are common sites of the lesion• Clinically the Actinic Keratosis is a hyperplastic

proliferative lesion• Over 50% of cases evolve into invasive squamous

cell carcinoma in a period of 3-5 years

SEBORRHOEIC KERATITIS It is a nodular /plaque like condition with

morphological appearance of “button stuck” on the skin

The condition commonly affects elderly male with skin of eyelid as common site histologically , Seborrhoeic Keratitis s characterised by marked acanthosis, hyperkeratosis and prominence of basal cell layer

The diagnostic feature that helps to distinguish seborrhoeic keratitis from squamous cell carcinoma or basal cell carcinoma is the location of the lesion entirely external to a line drawn from the adjacent normal epidermis

KERATOCANTHOMA It is one of the commonly mistaken benign

lesions for the squamous cell carcinoma Multiple proliferative nodular lesions occur

over face generally in the youth

TUMOURS

BASAL CELL CARCINOMA BCC is the commonest eyelid tumour over 40

years of age In the west BCC accounts for more than 80%

of malignant eyelid tumours. Clinically as the name rodent ulcer

synonymously used for BCC,the ulcerative nodular epithelial neoplasm has everted edges with burrowing of invading margins

CLASSIFICATION BCC is histologically classified into 5 types Multicentric Keratotic Adenoid cystic Morphea Adenoid

Basically the neoplasm shows proliferating basal cells in bulbous or lobular fashion with characteristic palisading of basal cells in the periphery of each lobule.

The basal lamina is prominent, sometimes hyaline The basaloid cells in some tumours exhibit

maturation to squamous and elaborate exuberant keratin when the lesion is called Keratotic BCC.

In Morphea type, the hyalinization or desmoplastic reaction is marked compared to neoplastic cellular component .

In adenoid or adenoid cystic carcinoma ,as the term denotes, the proliferating basal cells infiltrate dermis in delicate trabecular fashion, encircling small areas of loose tissue, giving adenoid or adenoid cystic appearance

SQUAMOUS CELL CARCINOMA Commonest eyelid tumour in the Indian

subcontinent. Elderly males are frequently affected with

upper eyelid being commoner than lower Exophytic,proliferative ,nodular or ulcerative

growth involving external aspect is the commonest clinical presentation

Histologically, the squamous cell carcinomas are characterized by proliferative polyhedral squamous cells with varying degrees of pleomorphism ,hyperchromasia invading the stroma in trabecular or lobular fashion.

MALIGNANT MELANOMA It is rare in India Malignant Melanoma , when it is young, one

should suspect associated Xeroderma Pigmentosum , a hereditary autosomal recessive disorder.

Clinically the pigmented lesion may occasionally be poorly pigmented, affecting the lid margin

It is a plaque or, nodule or rarely ulcerated lesion.

ADNEXAL TUMOURS It may arise from eccrine,apocrine or

holocrine The structural pattern of the adnexal

tumours of the eyelids do not differ from those that occur elsewhere in the body

Face is the commonest site for sebaceous gland tumours compared to other sites, so is the eyelid

SEBACEOUS CARCINOMA It is the most frequent eyelid tumour It ranks equal to the squamous cell carcinoma in

its incidence in India it may arise from Zeiss or meibomian glands

Upper eyelid is the commonest site and clinically ,early lesions mimic chalazion

Elderly males are more affected than females Sebaceous gland is a holocrine gland and the

secretions are the result of death of central cells

They have no distinct ducts in general and their secretions open into hair follicles.

However the meibomian glands which are embedded in the tarsal plate open at the lid margins through a separate duct lined by the squamous epithelium

Orifices of the ducts represent junction of skin and eyelid with palpebral conjunctiva

The sebaceous glands,exhibit peripheral basaloid cells which gradually mature towards centre acquiring foamy(lipid) character

It may be nodular ulcerative lesion or proliferative lesion.

External location is often due to its origin from Zeiss gland

Marginal or internal sebaceous carcinoma are the true meibomian gland gland carcinoma

It is characterised by irregular lobules of basaloid cells infiltrating the dermis

From the periphery the cells show maturation to foamy cells in the centre

The lobules or islands of the tumour are composed of oval to round cells, with deeply stained nuclei and clumped chromatin