Tumor Epithelium lecture 19 Flashcards

1
Q

Normal histology and function of the skin

A
  • Protective barrier ( Fluid loss, mechanical injury, and micro-organisms )
  • Sensation: Touch, temperature, pressure, and pain
  • Termoregilation
  • Control evaporation
  • Storage : lipids and water
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2
Q

Classification of skin layers

A

Upper surface: Epidermis (contains squamous cells and melanocytes)
Middle layer: Dermis (Contains blood vessels hair follicles and nerves, it is the connective tissue )
Lower layer: Hypodermis (contains nerves and larger blood vessels )

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3
Q

Discuss the squamous papilloma

A
  • Common benign cutaneous lesions

* The most common is a viral wart

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4
Q

Discuss the histology of squamous papilloma

A
  • Hyperkeratosis
  • papollomatosis
  • Acanthosis( think)
  • elongated rete ridges
  • koilocytosis
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5
Q

Discuss the histology of squamous papilloma

> Squamous Tumors

A
  • Hyperkeratosis
  • papollomatosis
  • Acanthosis( think)
  • elongated rete ridges
  • koilocytosis
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6
Q

Discuss the solar (actinic keratosis)

> ST

A

*It is due to chronic exposure to the sun
*More common in light-skinned individuals
*

Clinically you will see hyperkeratosis, tan/brown lesions and may form cutaneous horns

*may regress, remain unstable, or undergo malignant transformation

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7
Q

Discuss the histology of solar (Actinic ) keratosis

ST

A
  • Defining features (epidermal dysplasia (mild, moderate/severe)
  • Hyperkeratosis, parakeratosis, and solar elastosis (sun damage )
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8
Q

Discuss Bowen’s disease and its sites

A

> Carcinoma in-situ
Full-thickness epidermal dysplasia
HPV implicated

> Sites

  • skin: Bowen’s disease
  • Vulval intraepithelial neoplasm
  • Glans: Erythroplasia of queyrat
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9
Q

Discuss the squamous cell carcinoma Aetiology

A

> Commonly secondary to basal cell carcinoma
Often arises from pre-existing dysplasia eg solar keratosis but can arise de novo

1.Chronic sun exposure( most important) 
2Chronic ulceration (marjolin's ulcers) or scarring 
3.ionising radiation 
4.albinism ,xeroderma pigmentatosum 
5. chemicals  arsenic ,tar
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10
Q

What are the clinical manifestations of squamous cell carcinoma

A

> Raised, rolled, everted edges
often central ulcerations
Usually locally aggressive
and cured by excision

Recurrence :

  • twice as the frequency of BCC
  • Risk factor for recurrence include incompletion and aggressive histological patterns
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11
Q

Discuss the metastasis of the SCC

A
  • uncommon
  • deoendent on clinical setting :0,5%in sun-damaged skin vs % in marjolins ulcer
  • Usually to regional lymphoma nodes
  • pulmonary metastasis is uncommon
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12
Q

Discuss the histology of SCC

A
  • Invasion beyond the basement membrane into underlying dermis
  • Comprises nest of malignant squamous cells
  • Intercellular bridges ,abundant eosinophilic cytoplasm
  • keratin formation
  • mitotic activity
  • may have dysplasia of the overlying epidermis with or without ulceration
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13
Q

discuss the Seborrhoeic keratosis (AKA seborrhoeic wart / basal cell papilloma )

A

*It is common among middle-aged individuals
*Benign
*Arises spontaneously in the trunk, extremities, head, and neck
*Round, flat, dark plaques with a velvety granular surface
*has a stuck-on appearance
*

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14
Q

Discuss the seborrhoeic keratosis histology

A
  • Exophytic and sharply demarcated
  • Basaloid cells: small with dark nuclei and scanty cytoplasm
  • Variable melanin pigmentation
  • Exuberant keratin production
  • Horn cysts
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15
Q

Discuss the BCC

A
  • Due to UV exposure
  • most common malignant tumor
  • Usually elderly caucasian patients (in more sunny areas ,patients are often younger )
  • Mainly on the face and it cured by adequate excision
  • Locally aggressive but almost never metastasis
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16
Q

t/f: BCC are common malignant tumors

A

true

17
Q

BCC clinical presentation

A
  • nodule

* ulcer (rodent ulcer )

18
Q

Tumors of melanocytes classification

A

> Benign

  • melanocytic naevus
  • Blue naevus

> Pre-malignant
*Dysplastic naevus

> Malignant
*Melanoma

19
Q

Discuss the melanocytic naevi

A

> Benign
Commonly referred to as moles
Nests of bland melanocytes
Usually acquired but some are congenital
*Malignant transformation is rare eg giant congenital melanocytic naevus

20
Q

What are the 3 types of reflect progression monocytic naevi

A
  • Junctional
  • Compound
  • intradermal
21
Q

Dysplastic Naevi

A
  • Sporadic or familial
  • Larger and more irregular than benign naevi
  • The neoplastic melanocytes are larger and more atypical
  • May have fusion of the rete ridges or spindled melanocytes

*Significance : whilte americans : 0,6% lifetime risk of melanocyte and increases10 10% if dysplastic naevi are present

22
Q

Discuss melanoma

A
  • Malignant tumours of melanocytes
  • Currently no effective chemotherapy
  • Incidence is increasing
  • *Rare in children except for giant congenital naevus
23
Q

True or false: Melanoma only occur in cutaneous sites

A

*May arise in non-false; cutaneous sites eg eyes,

anus, meninges, and mouth

24
Q

What are the predisposing factors to melanoma

A
  • UV light / radiation
  • Albinism
  • Xeroderma pigmentosum
  • Dysplastic naevus syndrom
  • Gaint congenital naevus

> More common in light-skinned people (especially red hair and freckles )

> common sites : lower leg in females and trunk and back in males

> Rare in dark-skinned races except in acral sites eg palms and soles

25
Q

Melanoma clinical clues

ABCDEUS

A
  • Asymmetry
  • Border irregularities
  • Colour variegation
  • Diameter >6mm
  • Evolving lesion
  • Ulceration
  • Satelites lesions
26
Q

List 4 types of melanoma

A

> Lentigo maligna melanoma
*older men and face ,indolent

> Sperficial spreading melanoma
*Most common due to sun-exposed skin

> Acral lentiginous melanoma
*Common in black patients on their palms ,hands and soles and it is not related to sun exposure

> Nodular melanoma
*Vertical growth

27
Q

List the growth phases of the melanomas

A

> Lentigo maligna superficial spreading and acral lentiginous: Radial growth phase that is horizontal growth within the dremin and lacks the capacity to metastasis and amicable to curative excision

> Nodular melanoma: Vertical growth phase with dermal invasion and exponential risk of metastasis with depth

28
Q

What is the prognosis of melanoma

A

> Correlates with depth

  • Breslow’s tumor thickness
  • Clark’s level of tumor invasion

> Others :

  • Ulceration
  • Mitoses
  • Necrosis

> Spread via lymphatics and blood stream which contributes to prognosis

29
Q

t/f: Breslow’s tumor thickness tells us that the thinner the tumor the more the likelihood of metastasis

A

Fales, the Breslow tumor thickness tells us that the thicker the tumor the more the likelihood of survival

Tumor thickness / correlation
*< 0,76mm /metastasis rare ,potentially curable

  • 0,76-1,5mm : metastases in 25%
  • > 1,5mm :metastases in 75%
30
Q

List the Clarks levels

relates with which structure is involved

5 years survival decreases as the Clark level increases

A
  1. Epidermis only
  2. Into papillary dermis
  3. Junction between papillary and reticular dermis
  4. Into reticular dermis
  5. Into subcutaneous tissue
31
Q

Summary

A

The Breslow’s thickness correlates with the Clark levels

Skin tumours are common
Can arise from any of the cells making up the skin
Most important: basal cells, squamous cells, and melanocytes
Range from benign to highly malignant
Most are due to sun exposure
Most can be cured with surgery if detected early