Neoplasms Of The Skin - HIPON Flashcards
Which cell type is arranged across all five layers of the epidermis?
The keratinocytes.
Name the five layers of the epidermis.
- Stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
Describe briefly the stratum basale of the epidermis.
- Single layer of cuboidal to columnar cells that stand on the basement membrane.
- Region of cell division.
- Also contains melanocytes + Merkel cells.
Describe briefly the stratum spinosum of the epidermis.
- Many layers of polyhedral prickle cells bearing intercellular brigdes (keratinocytes).
- Mitotic activity is present.
- Also contains Langerhans cells and processes of melanocytes.
Describe briefly the stratum granulosum of the epidermis.
- Somewhat flattened cells containing keratohyalin granules.
- Absent as a distinct layer in the thin skin.
Describe briefly the stratum lucidum of the epidermis.
- Thin, translucent layer with cells containing eleidin.
2. Absent from thin skin.
Describe briefly the stratum corneum of the epidermis.
- Squames packed with keratin.
2. Superficial squames are desquamated.
Give a brief description of the dermis.
Dense, irregular, collagenous connective tissue subdivided into two layer:
- Papillary
- Reticular
Give a basic description of the papillary layer of the dermis.
- Dermal ridges (papillae) and secondary dermal ridges interdigitate with the epidermal ridges (+ interpapillary pegs) of the epidermis.
- Collagen fibers are slender.
- Capillary loops + Meissner’s corpuscles are found between the dermal ridges.
Give a basic description of the reticular layer of the dermis.1
- Composed of coarsed bundles of collagen fibers.
2. This layer supports a vascular plexus and interdigitates with the underlying hypodermis.
What may be present in the reticular layer of the dermis?
Frequently:
- Hair follicles
- Sebaceous glands
- Sweat glands
- Krause’s end bulbs
- Pacinian corpuscles
What is the most common neoplasm in terms of sheer numbers?
Tumors of the skin.
What is the most common warning sign of skin cancer?
Change in the appearance of the skin, such as a new growth or a sore that will not heal.
What is the main cause of skin cancer?
UV light
Besides UV light, mention some other factors that play a role in the development of skin cancer.
- Smoking tobacco
- HPV
- Aging
- Light skin color
- Artificial UV radiation
- Immunosuppressive drugs
What lesion may occur in areas of skin exposed to sunlight over a long period of time?
Actinic (solar) keratosis - with aberrant differentiation of the epidermal cells.
What is the origin of basal cell carcinoma of the skin?
It originates from the lowest layer of the epidermis - most common + least dangerous skin cancer.
What is the origin of squamous cell carcinoma of the skin?
It originates from the middle layer - less common, but more likely to spread and to be fatal.
What are the 2 forms of skin cancer that are collectively known as non-melanoma skin cancer?
- Basal cell carcinoma
2. Squamous cell carcinoma
What is the origin of melanoma?
It originated in the pigment-producing cells (melanocytes) - least common, but most aggressive, most likely to spread. Fatal if untreated.
Where does SCC of the skin commonly arise?
Chronically sun exposed areas:
- Backs
- Hands
- Lips
- Ears
What is the precancerous condition of SCC of the skin?
Actinic (solar) keratosis
What is the morphology of SCC of the skin?
Red, scaling, thickened patch on sun-exposed skin.
When does SCC of the skin have a low potential for metastasis?
When it arises on sun-damaged skin.
What is the most common location of basal cell lesions?
The face
Mention some not sun-exposed areas, in which a basal cell carcinoma can occur?
- Chest
- Back
- Arms
- Legs
- Scalp
What is the gross morphology of a basal cell carcinoma?
- Begins as a small, dome-shaped bump.
- Often covered by small, superficial blood vessels –> Telangiectases.
- Texture is often shiny and translucent - sometimes referred to as “pearly”.
What types of adnexal neoplasms of the skin may occur?
Neoplasms that involve:
- Hair follicles
- Sweat glands/Ducts
- Sebaceous glands
What is a keratoacanthoma?
Neoplastic proliferation of the infundibular portion of the hair follicle.
With what can keratoacanthoma be confused both clinically and microscopically?
With SCC.
What is the characteristic morphology of keratoacanthoma?
Dome-shaped lesion in which there is a central crater filled with keratin.
What is the classic course of keratoacanthoma?
It arises from a previously normal portion of the skin, waxes rapidly over the next 4-6 weeks and then regresses over a further 4-6 weeks, leaving a depressed scar.
Mention an aggressive tumor of the skin that derives from neuroendocrine cells.
Merkel cell tumor.
What is the microscopic morphology of Merkel cell tumor?
Uniform proliferation of small, round, dark cells, this being responsible for the not infrequent misdiagnosis of cutaneous lymphoma.
How do we classify the benign melanocytic tumors (nevi)?
According to the level within the skin where the melanocytic proliferation is predominant.
What are the 3 most common variants of benign melanocytic tumors?
- Junctional
- Intradermal
- Compound
Mention some rare variants of benign melanocytic tumors.
- Blue nevus
- Spitz nevus
- Pigmented spindle cell nevus of Reed
What is estimated about the incidence of melanoma?
Over 1% of children born today will develop malignant melanoma.
What is the prognosis of most melanomas and on what does it depend?
Excellent prognosis, if lesions are recognized and excised before entering a vertical growth phase.
When is a patient with melanoma at risk of dying from metastatic disease?
If the tumor exceeds a critical depth in the dermis.
Where do men most commonly develop melanoma?
On the trunk, particulalry at the back.
Where do women most commonly develop melanoma?
Legs or arms.
What is the usual color of a melanoma?
Various colors from shades of brown to black.
What are the amelanotic melanomas?
A small amount of melanomas are pink, red, or fleshy in color.
What is the prognosis of amelanotic melanomas?
They tend to be more aggressive.
What are the main warning signs of melanoma?
A change in:
- Size
- Shape
- Color
- Elevation of the mole
What are the main connective tissue tumors of the skin?
- Fibrous histiocytoma
- Dermatofibrosarcoma protuberans
- Tumors/Tumor-like conditions arising from blood vessels
What are the 4 cellular components of the epidermis?
- Keratinocytes
- Melanocytes
- Langerhans cells
- Merkel cells
