Skin Neoplastic Conditions Flashcards
1
Q
Malignant tumors
A
- Squamous Cell Carcinoma (SCCA)
- Basal Cell Carcinoma (BCCA)
- Malignant Melanoma
2
Q
Squamous cell carcinoma (SCCA)
A
- 2nd most common tumor of sun-exposed sites in older people
- Higher incidence in men > women
- Invasive / Metastasize
3
Q
Morphology of noninvasive SCCA lesions
A
- Sharply defined / red / scaling plaques
- No invasion through the basement
- Termed carcinoma in situ (CIS)
4
Q
Morphology of invasive SCCA lesions
A
- Nodular
- Variable keratin production
- Ulceration
5
Q
Morphology of SCCA (CIS)
A
- Atypical nuclei
- Enlarged and hyperchromatic
6
Q
Morphology of invasive SCCA (CIS)
A
- Polygonal cells in lobules (large areas of keratinization)
- Necrosis / anaplasia (exhibit dyskeratosis)
7
Q
Pathogenesis of malignant tumors
A
- UV induced DNA damage to squamous cells
- Ionizing radiation
- Old burn scars
8
Q
UV induced DNA damage to squamous cells
A
- Incidence is proportional to lifetime sun exposure
- UV rays attack Langerhans cells
- Defects in p53 / RAS
9
Q
SCCA association with chronic immunosuppression
A
- Chemotherapy
- Organ transplantation (Reduced host surveillance, HPV subtypes 5 and 8)
10
Q
Basal cell carcinoma (BCCA)
A
- Most common invasive cancer in humans
- 1 million estimated cases per year in US
- Slow-growing tumors
- Rarely metastasize
- Occur at sun-exposed sites
11
Q
BCCA incidence
A
- Increased immunosuppression
- Increased xeroderma pigmentosum
12
Q
BCCA presentation
A
- Present as pearly papules
- Prominent subepidermal blood vessels (telangiectasias)
- Melanin production
13
Q
BCCA advanced lesions
A
- Ulceration
- Extensive local invasion
14
Q
Extensive local invasion of BCCA
A
- After many years of neglect
- Aggressive tumors (bone, facial sinuses)
15
Q
BCCA morphology
A
- Tumor cells resemble the normal basal cell
- Arise from the epidermis or follicular epithelium
- Do not occur on mucosal surfaces
16
Q
2 patterns of BCCA
A
- Multifocal growths
- Nodular lesions
17
Q
Multifocal growths of BCCA
A
- Originate from epidermis
18
Q
Nodular lesions of BCCA
A
- Downward growth deep into dermis as cords
19
Q
BCCA morphology (histology)
A
- Multifocal growths
- Nodular lesions
- Palisading
- Retraction
20
Q
Molecular pathogenesis of BCCA (gene mutations)
A
- PTCH signaling pathway
- SMO activating mutations
- Mutations in p53
21
Q
Disorders of pigmentation and melanocytes
A
- Melanocytic Nevus (moles)
- Dysplastic Nevus
- Malignant melanoma
22
Q
Melanocytic nevus (moles)
A
- Neoplasm of Melanocytes
- Most are Acquired (activating mutations in RAS or BRAF pathways)
23
Q
Common acquired melanocytic nevi
A
- Junctional
- Compound
- Intradermal
24
Q
Characteristics of commonly acquired melanocytic nevi
A
- Tan –> brown
- Uniformly pigmented
- Small (usually <6 mm across)
- Flat (macules) –> elevated skin (papules)
- Well-defined / rounded borders
25
Series of morphological progression of melanocytic nevi
- Juntional --> compound --> intradermal
26
Junctional nevi (earliest lesion) morphology
- Nests of round cells that grow along the dermoepidermal junction
- Nuclei are uniform and round
- Inconspicuous nucleoli
- Little or no mitotic activity
27
Melanocytic nevus progression
- Growth into underlying dermis (matures with depth)
| - Nests and cords (compound nevi)
28
Intradermal nevi
- Epidermal nests form pure intradermal nevi
29
Intradermal nevi undergo maturation into
- Fusiform cells
| - Melanomas (show little or no maturation)
30
Congenital nevus distinguishing features
- Deep dermal / sub Q
- Multiple growth patterns
- Large variants
31
Growth patterns of congenital nevus
- Adnexa
- Blood vessels
- Neurovascular bundles
32
Large variants of congenital necus
- Increased risk of skin cancer
33
Variants of melanocytic nevi
- Congenital nevus
- Blue nevus
- Spitz nevus
- Halo nevus
34
Blue nevus distinguishing features
- Non-nesting / dermal infiltration / fibrosis
- Heavily pigmented
- Clinically confused with melanoma
35
Spitz nevus distinguishing features
- Fasicular growth pattern
- Plump and fusiform cells with pink-blue cytoplasm
- Clinically confused hemangiomas
36
Halo nevus distinguishing features
- Lymphocytic infiltration surrounding nevus
| - Host Immune Response (nevus cells, melanocytes)
37
Dysplastic nevi
- Precursors of melanoma
| - Most are clinically stable with no progression
38
Dysplastic nevus characteristics
- >5 mm across
- Flat macules --> slightly raised plaques
- Pebbly surface
- Cytological atypia
39
Dysplastic nevus important recognition patterns
- Size
- Variability in pigmentation (variegation)
- Irregular borders
- Sun-exposed areas
- Protected body surfaces
40
Dysplastic nevus nuclei
- Large
- Irregular
- Angulated
- Hyperchromatic
41
Dysplastic nevus microscopic morphology
- Cytologic Atypia
- Cells are enlarged
- Coalescence with adjacent nests
- Lentiginous hyperplasia
- Superficial dermis
42
Superficial dermis involvement with dysplastic nevi
- Lymphocytic infiltrates
- Melanin incontinence
- Fibrosis surrounding the rete ridges
43
Gene associations with dysplastic nevi pathogenesis
- CDKN2A
- CDK4 (cyclin-dependent kinase 4)
- NRAS
- BRAF genes
44
Pathogenesis of dysplastic nevi
- Inherited genes
| - Sun exposure
45
Important pathways in dysplastic nevus pathogenesis
- Regulate cell survival
- Proliferation
- PI-3K/PTEN/AKT
- BRAF/ERK
46
Malignant melanoma associated conditions
- Melanocytic Nevi
| - Dysplastic Nevi (precursors of Melanoma)
47
Malignant melanoma
- Deadly if not diagnosed in early stages
| - Preponderance
48
Preponderance to malignant melanoma
- Skin
- Oral
- Anogenital mucosal surfaces
- Esophagus
- Meninges
- Eye
49
Clinical features of malignant melanoma
- Aggressive metastatic tumors
| - Resistant to therapy
50
Presentation of malignant melanoma
- Asymptomatic
- Itching / pain
- > 10mm
51
Important warning signs of malignant melanoma
- Asymmetry
- Borders (Irregular)
- Color (Variegated color)
- Diameter (> 6 mm)
- Elevation
- Change in appearance
- New onset of itching or pain
52
Progression of melanoma
- Radial growth phase --> vertical Growth Phase
53
Radial growth phase of melanoma
- Horizontal Spread (epidermis, superficial dermis)
| - Lack the capacity to metastasize
54
Vertical growth phase of malignant melanoma
- Downward invasion
- Appearance of a nodule
- Cells lack maturity (Regression)
55
Probability of metastasis of malignant melanoma
- Proportional to depth of invasion
| - Distance / Granular cell layer --> deepest intradermal tumor cells (Breslow Thickness)
56
Prognostic factors (metastasis of malignant melanoma)
1. Tumor depth (the Breslow thickness)
2. Number of mitoses
3. Evidence of tumor regression
4. Tumor infiltrating lymphocytes (TILs)
5. Gender
6. Location (central body or extremity)
57
Favorable determinants (malignant melanoma)
- Depth of less than 1.7 mm
- None / very few mitoses
- TIL response
- Absence of regression
- Female gender
- Location on an extremity
