Transcript From: Gorlin, 2004.

Handout
SKIN DISEASES: An
Integrated Clinicopathologic
Approach- Med 1
Dr. M. G. Joseph, Professor
Dept. of Pathology, LHSC
Specific Objectives
Recognize common skin tumours, basics.
An integrated clinicopathologic approach
•
Summarize important points learned from
previous and upcoming clinical
lectures…where to focus (few clinical images
from previous lectures are used to reemphasize concepts)
•
Dermatology Mini Atlas
WebCT
For Self Study/ Practice Review
Important for end of the course Image
Quiz examination
•
Skin Tumours
Basics
Behaviour
• Benign Tumour
• Malignant Tumour
Histogenesis (origin)
• Epidermal
• Dermal
• Adnexal
Primary vs metastatic tumour
SKIN TUMOURS
(Histogenesis)
•
Epidermis
- Squamous cells
- Basal cells
- Melanocytes
Adnexal tumours
• Dermal (Mesenchymal)
•
- Collagen
- Smooth muscle
- Blood vessel
- Nerve
•
Lymphoma/leukemia
•
Metastatic tumours
How to Describe a Lesion
SCALDA for Tumours
Size
• Color
• Arrangement (configuration)
• Lesion morphology
• Distribution
• Always check hair, nail, mucosa,
intertriginous areas
•
Skin Cancer
Basics
Skin cancer is the most common form of cancer in
human.
• It is estimated that approximately 75,000 canadians
will develop skin cancer every year
• 3 histologic types account for about 99% of all skin
cancers.
•
- Basal cell ca, Squamous cell ca, Melanoma
•
All are caused by chronic sun exposure
- Cumulative amount important for squamous cell ca
- Intermittency and amount of exposure important
for basal cell ca and melanoma
Skin Cancer, Common Types
•
Basal cell carcinoma
- Most common type of skin cancer, 80% of all
cancers, sun damaged skin, elderly
- Several subtypes of BCC, nodular most common
- Slow growing, locally invasive, do not metastasize
- Histology- malignant proliferation of basaloid
cells of epidermis
Basal cell carcinoma
2 Common subtypes
Nodular
Ulceronodular
A well circumscribed
Pearly white/pink nodule
Ulcerated nodule
with surface telengiectasia
with rolled edges
Nodular Basal Cell Carcinoma
A well circumscribed nodule, origin from basal cells
of epidermis and infiltration into dermis
Basal cell carcinoma
B
A
C
Nests of basaloid cells (A), peripheral palisading of
nuclei (B), loose fibrous stroma (C)
Multiple BCCs in a young patient
Gorlin
Syndrome
Multiple BCCs
Young patient
Back
Look for ……..
Palmar pits
Bifid ribs
From: Gorlin, 2004.
Nevoid BCC (Gorlin Syndrome)
•
Autosomal dominant, 0.4% of all BCC cases
•
Most cases reflect mutation in the
patched gene (PTCH) chromosome 9q22-q31
cause upregulated cell proliferation
2% of patients under age 45 years
with BCC have NBCC syndrome
•
Gorlin Syndrome
1. Predisposition to various tumours
Odontogenic keratocysts
Medulloblastoma brain
Fibromas of ovary, heart
2. Other skin manifestations
Palmar and plantar pits
Multiple epidermal cysts
3. Cleft lip/ palate, macrocephaly
Skin Cancer, Common Types
•
Squamous cell carcinoma
- Second most common cancer of skin
- Sun damaged skin, elderly
- Locally invasive, can metastasize (5-10%)
- Histology: malignant proliferation of epidermal
keratinocytes.
- squamous cell carcinoma is of 2 types
•
•
Insitu squamous ca (Bowen’s disease)
Invasive squamous ca
Bowen’s disease - insitu SCC
Sharply demarcated
red scaly patch
Proliferating malignant
keratinocytes confined to epidermis
Origin - epidermal squamous cells
Invasive Squamous Cell Carcinoma
SCALDA
skin colored
indurated
and ulcerated
nodule
on lip
Invasive Squamous cell carcinoma
B
A
Origin- from squamous epithelium, invades into dermis
Malignant squamous cells (A) invading dermis (B)
Skin Cancer
•
Malignant Melanoma
Malignant tumour of melanocytes
- Least common, most deadly type of skin
cancer
–
Common Benign/premalignant
Tumours of skin
Seborrheic keratosis
• Corn, Skin tag
• Wart, Molluscum contagiosum
• Solar keratosis (premalignant)
• Dermatofibroma
• Epidermal cyst, Pilar cyst
• Keratoacanthoma (benign vs
malignant, contraversial)
•
Seborrheic keratosis
A common benign epidermal tumour
SCALDA
multiple brown
scaly papules
/plaques
stuck on
appearance on
the trunk
Seborrheic keratosis
pigmented type
Single well circumscribed
brown scaly papule/nodule,
Stuck on (pigmented sebka)
Skin tag, benign
Soft skin colored pedunculated papule/nodule
Corn, benign: painless keratotic papule,
clear core, central depression
Thick stratum corneum (hyperkeratosis)
Wart: scaly verrucous flesh colored
papule/nodule, red spots (arrow)
HPV Virus cause
Hyperkeratosis, acanthosis,
viral changes in cells (arrow)
dilated vessels (red arrow)
Molluscum
Contagiosum
Multiple
umbilicated
skin coloured sma
papules
Pox virus- cause
Actinic Keratosis (premalignant
squamous lesion)
Multiple poorly demarcated reddish brown rough
scaly papules and plaques on sun damaged skin
Actinic Keratosis
A
B
For information only
Parakeratosis
(arrow)
Atypical
keratinocytes (A)
Sun damaged
dermis (B)
Keratoacanthoma (Benign ?)
1.5 cm well circumscribed
skin colored
nodule with central keratin
filled Crater
Rapid growth in few wks
Spontaneous remission
in few weeks
SCALDA
Keratoacanthoma vs SQCC
Clinical similarity, excise completely
Keratoacanthoma
Benign proliferation of
keratinocytes
Squamous cell ca
Malignant proliferation
of keratinocytes
2 common benign skin cysts
basics
Epidermal cyst (most common, face, neck,
trunk)
Pilar cyst (scalp)
Cyst: sac filled with fluid or semisolid material
(fluctuant) and is lined by epithelium
Epidermal cyst (most common benign
skin cyst in dermis)
Slowly growing, painless, round, soft, mobile, fluctuant
skin coloured nodules, may have a central punctum
Inflammed epidermal cysts (painful)
Punctum
Pilar cyst (second common skin cyst scalp)
Lining epithelium and keratin are different from
epidermal cyst, clues for pathologist
Common Benign Dermal
Tumours - origin
Dermatofibroma - fibroblast
Lipoma - lipocytes (fat cells)
Hemangioma - blood vessel
Neurofibroma - nerve
Pyogenic granuloma -blood vessel
This firm nodule is present for
years. Dermatofibroma (benign
dermal tumour)
Tan firm papule, may be pigmented, dimple sign
Firm well circumscribed brownish red nodule on le
Dermatofibroma
Dermatofibroma (Dimple sign/
Fitzpatrick’s sign)
Benign proliferation of fibroblasts
Hemangioma
Benign vascular
tumour, congenital or
acquired, small or
large, flat or elevated
Cherry red colour
Pyogenic granuloma, benign
(Lobular capillary
hemangioma)
A pedunculated red nodule
that bleeds, history of trauma
Vascular proliferation
Melanocytic Tumours
Melanocytic Neoplasia
•
Benign nevus
- lentigo simplex, junctional N, compound N,
intradermal N
- Spitz N, Blue N, Halo N, Congenital N.
Dysplastic nevus (atypical nevus)
• Malignant melanoma (insitu/invasive)
•
Evolution of Benign Nevus
Lentigo simplex
• Junctional nevus
• Compound
• Intradermal
•
Nevus evolution
Junctional, Compound, Intradermal N
Lentigo
simplex
JN
CN
IDN
Life cycle of nevus
Compound nevus
2 pigmented lesions present for the
past 10 years. What are they?
Blue nevus
Halo nevus
Halo nevus (Regressing Nevus)
This patient has dysplastic nevus syndrome
Dysplastic nevus
ABCD criteria
Dysplastic Nevus- Clinical
Large size (5mm-12mm.) - 72%
• Irregular
• Asymmetry
• Irregularity of colour-84%
• Presence of a central papule and
peripheral macular component
•
Dysplastic Nevus
Dysplastic nevus syndrome: Affected
people develop large number of
dysplastic nevi and are associated with
increased incidence of melanoma
• Isolated dysplastic nevi in patients
without personal or family history of
melanoma is main source of
controversy, incidence 5-20%
•
For information only
Dysplastic nevus
For information only
This Nevus shows
architectural and
cytological atypia
Dysplastic Nevi –Key Points
Considered as a risk marker for melanoma,
risk increases with number of nevi.
• May be potentially a precursor for melanoma,
dysplastic nevus present adjacent to an
invasice melanoma in 36% of melanoma
cases.
• Individual lesions, sig . unknown
• Patients with many lesions should be
periodically monitored
•
Malignant melanoma, basics
Objectives
How to diagnose melanoma
• List 4 types of melanoma
• List 5 prognostic factors of melanoma
•
How to Diagnose Melanoma
(ABCDE check list)
Asymmetry
• Border irregularity-notched border
• Color variegation-red, white, blue
• Diameter greater than 6mm
• Elevation/enlargement (recent)
•
4 Types of Melanoma
Lentigo maligna (insitu), lentigo
maligna melanoma (invasive)
• Superficial spreading melanoma, in
situ and invasive
•
Acral lentiginous melanoma, in situ
and invasive
• Nodular melanoma (always
invasive)
•
4 Types of Melanoma (important slide)
The most common form of melanoma:
-in African-Americans is acral lentiginous Melanoma
-associated with chronically sun-exposed skin is lentigo maligna melanoma
1 Superficial spreading M, leg
2 Nodular M
3 Acral lentiginous M
Nodular melanoma, small
4. Lentigo maligna M face
Normal to insitu melanoma evolution
Normal
Pagetoid intraepidermal spread
Invasive melanoma - invasion into dermis
Breslow thickness- prognostic factor 1
Breslow thickness:
measured from epidermal
granular layer to deepest
melanoma cell in dermis
Clark level l – V - prognostic factor 2
I
II
III
IV
V
I Confined to epidermis (in situ)
II Invasion of papillary dermis
III Fills the papillary dermis
IV Invasion of reticular dermis
V Invasion of subcutaneous fat