metabolic changes and degeneration
Post on 14-Feb-2017
16 Views
Preview:
TRANSCRIPT
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
top related