Skin Continued... Malignant Epidermal Tumors Flashcards
- Explain and compare the pathology of malignant epidermal tumors – squamous cell carcinoma (SCC) and basal cell carcinoma (BCC).
a. Involvement of UV radiation or sun damage
SCC is sun related
as is BCC
- Explain and compare the pathology of malignant epidermal tumors – squamous cell carcinoma (SCC) and basal cell carcinoma (BCC)
b. Association with a mutation in either tumor protein p53 (TP53) gene, HRAS or proteins that cause dysregulation of the Hedgehog pathway.
Squamous cell-TP53 in both, involves HRAS (onco-gene)
Basal Cell: TP53
Explain and compare the pathology of benign and premalignant epithelial lesions – seborrheic keratosis and actinic keratosis.
a. Involvement of UV radiation or sun damage
Actinic=solar keratosis
-balding scalp, lateral neck, distal upper and lower extremities
Seborrheic is not sun related- age related with unknown cause
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis.
b. The cause or risk factors
Actinic-sun exposure (UV) which causes DNA damage
Seborrheic- age related with unknown cause –> somatic mutation in fibroblast gene FGFR3
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis.
c. Association with a mutation in either the gene for fibroblast growth factor receptor 3 or tumor protein p53 (TP53).
i) How does that affect the protein produced (e.g. constitutively active or non-functional)?
Actinic–> UV –> TP53 mutation (tumor supressor) –> proliferation of basal cells –> intraepithelial dysplasia
Seborrheic keratosis –> age-related but a somatic gene mutation occurs with unknown cause to fibroblast growth receptor gene FGFR3 mutating it and making it CONSTITUTIVELY ACTIVE –> increased proliferation of epithelial cells –> excess keratin production
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis.
iii) Which causes dysplasia?
Actinic causes proliferation of basal cells which leads to intraepithelial dysplasia
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis (3)
and actinic keratosis (4)
d. Characteristic histological features – why and how these occur.
Seborrheic keratosis Histological Features
- Acanthosis-epidermal thickening
- HORN CYSTS-filled with keratin
- No Rete Ridges
Actinic Keratosis
- Partial Thickness dysplasia on bottom half of epidermis
- Hyperchromasia (dark nuclei)
- Varied nuclei and cell shape with loss of orientation (pleomorphism)
- Hyperkeratosis and parakertosis
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis.
e. Appearance and type of skin lesion (gross level) – why and how these occur.
Seborrheic Keratosis
- Tan/Brown (melanin)
- STUCK ON appearance
- Waxy-loss of keratin
- plaque-raised
- scaly
Occurs on trunk, extremities, neck, and head
Actinic Keratosis
- Zone of Redness (erythematous macule or patch)
- Scaly (hyperkeratotic)
Balding head, neck, distal extremities
Explain and compare the pathology of benign and premalignant epithelial lesions –
seborrheic keratosis
and actinic keratosis.
f. Progression to skin cancer?
Actinic can either persist, or progress to in situ SCC (and then maybe invasive-hopefully not) which is full thickness dysplasia (this makes sense, it goes from just half dysplasia to full)
Seborrheic does not
- Explain and compare the pathology of malignant epidermal tumors –
squamous cell carcinoma (SCC) and basal cell carcinoma (BCC)
a. Involvement of UV radiation or sun damage
b. Association with a mutation in either tumor protein p53 (TP53) gene, HRAS or proteins that cause dysregulation of the Hedgehog pathway.
Both sun exposed…
Squamous cell= TP53 and HRAS (oncogene)
Basal Cell= P53 mutation and deregulation of the Hedgehog pathway
- Explain and compare the pathology of malignant epidermal tumors –
squamous cell carcinoma (SCC)
basal cell carcinoma (BCC).
b. Association with a mutation in either tumor protein p53 (TP53) gene, HRAS or proteins that cause dysregulation of the Hedgehog pathway.
i) How does that affect the protein produced (e.g. constitutively active or non-functional)?
ii) What affect does this have on basal cells/keratinocytes?
Squamous cell= TP53 and HRAS (oncogene)
Basal Cell= P53 mutation and deregulation of the Hedgehog pathway
Basal Cell:
This can cause destruction of tissue..
SCC: overexpression of keratinocytes
- Explain and compare the pathology of malignant epidermal tumors –
squamous cell carcinoma (SCC)
basal cell carcinoma (BCC).
c. Likelihood of metastasis or local invasion.
Invasive SCC; penetrates all epidermis and through the BM-CAN METASTASIZE
Basal Cell: RARELY METASTASIZE
BOTH SCC AND BCC ARE LOCALLY INVASIVE
- Explain and compare the pathology of malignant epidermal tumors –
squamous cell carcinoma (SCC) -3 things
basal cell carcinoma (BCC) - 3 things
d. Characteristic histological features – why and how these occur.
Squamous cell:
Histological features
1. Full thickness dysplasia
2. Carcinoma invaded dermis (when should be mainly collagen) –> nuclear crowding and disorganization
3. Keratin pearls: cells that make arrangements of keratin into
swirls
Basal cell:
Histological features
1. Nests of uniform basaloid cells in dermis-RING LIKE?
2. Very blue staining cells with hyperchromatic, oval nuclei
3. Palisade arrangement of cells (resembles the basal layer of the
epidermis)
- Explain and compare the pathology of malignant epidermal tumors –
squamous cell carcinoma (SCC)-5
basal cell carcinoma (BCC)-4
e. Appearance and type of skin lesion (gross level)
Flat or elevated?
Scaley??
Blood vessels??
Surrounding tissue?
Gross features:
1. Nodule (elevated lesion)
2. Prominent keratinization (scales)
3. Central ulceration – no blood supply, necrotic center
4.Hyperpigmentation
5. Often lesion is tender, ulcerated or rapidly growing, prominent
keratinization (scales)
Gross features
- PEARLY PAPULE –> NOT SCALY
- Dilated subepidermal blood vessels
- No scales or hyperkeratosis
- Ulceration and destruction of the surrounding tissue
- Explain and compare the pathology of malignant epidermal tumors –
g. What are the main differences between cutaneous squamous cell carcinoma and oral squamous cell carcinoma?
- 3 things (serous? where? appearance?)
also
i) Causes or risk factors-Not sure about this one
h. Progression from actinic keratosis
Oral squamous cell carcinoma
1. Much more aggressive than cutaneous SCC
- Commonly found on floor of mouth and lateral or ventral
tongue-does not arise from actinic keratosis - May arise in sites of erythroplakia (premalignant persistent
red patches) or leukoplakia (persistent white plaques)
- Explain and compare the pathology of malignant epidermal tumors –
squamous cell carcinoma (SCC)
basal cell carcinoma (BCC).
f. Involvement of the oral mucosa or mucous membranes.
SCC in oral mucosa
BCC NOT
- Explain and compare the pathology of malignant epidermal tumors –
squamous cell carcinoma (SCC)
basal cell carcinoma (BCC).
h. Progression from actinic keratosis
SCC arises from actinic
BCC-it is unknown
A 60-year-old female presented to her dermatologist with a rough, scaly, erythematous papule on her cheek. She has no other health issues. A biopsy of the lesion most likely showed:
A. Acanthosis with horn or keratin filled
cysts in the epidermis
B. Full thickness dysplasia of the epidermis
with hyperkeratosis and parakeratosis
C. Groups or nests of uniform basaloid cells
in the dermis
D. Parakeratosis and acanthosis with
downward extension of the rete ridges
E. Superficial dermal edema
SCC-B. Full thickness dysplasia of the epidermis
with hyperkeratosis and parakeratosis
Explanations for others A. seborrehic C. Basal cell carcinoma D. Psoriasis E. uticaria
A 35-year-old male presents to his primary care physician with a complaint of red, scaly plaques on his elbows. When he pulls off the scale, the skin looks smooth, red, and glossy with tiny punctate bleeding. He has hayfever, but is otherwise healthy and has not come in contact with ‘anything new’ in the last few weeks. He is most likely diagnosed with: A. Acute eczematous dermatitis B. Bullous Pemphigoid C. Lichen planus D. Psoriasis E. Urticaria
D. Psoriasis
this shit is gross
A pathologist examines a biopsy from the esophagus of a 45-year-old male with longstanding GERD. He notes columnar epithelial cells with goblet (mucus producing) cells instead of the normal stratified squamous epithelium. The specimen show no cellular atypia. He most likely has: A. Atrophy B. Dysplasia C. Hyperplasia D. Metaplasia E. Necrosis
Metaplasia
A raised, brown, stuck on looking thing is what
seborrheic keratosis
Red erythematous macule which is rough/scaly/keratotic
Actinic keratosis
