Bumps and lumps Flashcards
Keratinocytes
Seborrheic Keratosis
What kind of tumor is it?
The sign of Lesser-Trelat is a marker of______.
- Common benign skin tumor of adults
- Clonal expansion of epidermal keratinocytes
Numerous eruptive lesions (sign of Leser-Trelat) may be a marker of internal malignancy.
- Discrete “stuck-on” appearing light to dark brown plaques, velvety or verrucous surface
- ** No treatment necessary
Keratinocytes
Seborrheic keratosis
Subtype
Dermatosis Papulosa Nigra: small, pigmented seborrheic keratoses usually occurring on the face of people with Fitzpatrick skin type V or VI.
Keratinocytes
Actinic (solar) Keratosis
What causes it?
Epidemiology
Most common pre-cancerous skin lesion
Pathogenesis
–Sunlight
–Hereditary (blue eyes, red/blond hair)
What causes similar lesions?
-Arsenical keratosis
-Radiation keratosis
Keratinocytes
Actinic (solar) Keratosis
What is its distribution in the body?
how does the primary lesion looks?
**Photodistribution- face, dorsum of hands, arms
**Arsenical keratoses- anywhere, especially palms
***Radiation keratoses- site of radiation
Primary lesion
–>1-10 mm scaly erythematous irregular papules
–>Variants- hyperkeratotic, pigmented, cutaneous horn
Actinic cheilitis- lip equivalent
Actinic keratosis with **cutaneous horn**
What other skin diseases can have cutaneous horns?
Does Actinic keratosis has the potential to become malignant?
It can become what?
Incidence of AK becoming a SCC
Study results 0.24% to 20%
Best figure: 1-5% lifetime
Spontaneous remission
- 25% in 1 year in 1/3 of patients
- 60% of SCC arise in pre-existing AK
Melanocytes are related to:
What is a Nevi?
Nevi = Moles
Melanoma
Ephelides = Freckles
Lentigo = Sun Spots
Café au lait macule
- Proliferation of melanocytes in the epidermis and/or dermis
- Can be congenital, acquired, sun-induced, atypical, or malignant (melanoma)
- Variants include blue nevi, halo nevi, congenital nevi
- Genetics and sun exposure are contributing factors
- Number of nevi linked to development of melanoma
Atipic (Dysplastic) Nevus
Dysplastic nevi (atypical nevi, Clark’s nevi, nevi with disordered architecture and cytologic atypia) are a subgroup of nevi which have an irregular outline, variable pigmentation, indistinct borders, and can be larger than 6mm in diameter.
Often described as having a “fried-egg” appearance, they typically have a dome-shaped central brown papular component surrounded by a flatter zone of light brown or tan pigmentation. When multiple dysplastic nevi are present in a patient with a family history of melanoma, they herald an increased risk for the development of melanoma in that patient. The presence of a single or few dysplastic nevi outside the context of a family history of melanoma may or may not portend an increased risk for that patient
Examples of atypical nevi
Sporadic Dysplastic nevus syndrome
Familial Atypical Nevi
(FAMMM syndrome)
Familial Atypical Nevi
(FAMMM syndrome)
Risk of developing malignant melanoma from FAMMM:
Blue Nevus
Halo Nevus
Congenital Nevus
- May be solitary or multiple
- May affect any cutaneous surface
- Primary lesion identical to acquired nevi only differ in size- 1 mm to huge (i.e.bathing trunk nevi)
– Presence of dark hairs- no clinical significance
• Complications
– Head, neck, posterior midline- cranial and or leptomeningeal melanocytosis
• Congenital nevi
– 1% of newborns
• Size
– Small (<1.5 cm diameter)
– Intermediate (1.5-20 cm diameter)
– Large (>20 cm diameter) • Treatment
– Highly controversial area
– Elective surgical excision
Most authorities do not recommend
Recommended by some if clinically feasible
– Dermabrasion
• Performed by a minority of authorities
• Risk for Melanoma
– Medium to Large Congenital nevi > 10 cm
• Occur in 1:20,000 newborns
– Calculated potential for malignant melanoma
• Risk 1% per year in large congenital nevi (>20 cm diameter) – Malignant melanoma in congenital nevi
50% appear in first 3 years
60% appear in first decade