Dermatopathology: Non-pigmented lesions Flashcards
Most common benign skin tumor of keratinocytes
Seborrheic Keratosis
What is the age of the typical patient with Seborrheic Keratosis?
Middle age or older
Where does Seborrheic Keratosis develop on the body?
Anywhere except palms/soles
What is the skin color of the typical patient with Seborrheic Keratosis?
Tan-black
Condition where lesions have waxy, “stuck-on” appearance, and keratotic plugs are seen on close exam
Seborrheic Keratosis
Keratotic plugs are seen in this condition
Seborrheic Keratosis
Condition with this morphology:
Well-demarcated papule/plaque
Small/immature appearing keratinocytes
Pseudo-horn cysts
Flat bottom
Hyperkeratosis
Seborrheic Keratosis
What causes Seborrheic Keratosis?
FGFR-3 activating mutations and TGF-alpha
FGFR-3 activating mutations and TGF-alpha drive this condition
Seborrheic Keratosis
Term for when paraneoplastic syndrome may produce abrupt increase in size/number of Seborrheic Keratoses
Leser-Trelat sign
What is the Leser-Trelat Sign?
Paraneoplastic syndrome may produce abrupt increase in size/number of Seborrheic Keratoses
The Leser-Trelat sign is involved in what condition?
Seborrheic Keratosis
Condition involving velvety hyperpigmentation of intertriginous and extensor surfaces
Acanthosis Nigricans
Acanthosis Nigricans is most common on these 2 regions of the body
Neck and Axilla
Acanthosis Nigricans is associated with these 2 conditions
Insulin resistance (type 2 DM)
Internal malignancy
In Acanthosis Nigricans, signaling through this causes dermal expansion, keratinocyte hyperplasia, and melanocyte pigment production
FGFR3 (Fibroblast growth factor receptor)
2 molecules produced in some neoplasms or endocrine disorders that are involved in Acanthosis Nigricans
TGF-alpha and IGF
Condition where papillary dermis expands and pushes into epidermis producing papillomatosis
Acanthosis Nigricans
Benign Acanthosis Nigricans is associated with these 3 factors
Obesity
Insulin resistance
Drugs (hormonal contraceptives)
Malignancy-associated Acanthosis Nigricans is most commonly related to this cancer
GI carcinoma
Malignancy-associated Acanthosis Nigricans in pediatric patients is associated with this cancer
Osteosarcoma
Rare inherited forms of Acanthosis Nigricans involve mutations of this
FGFR (fibroblast growth factor receptor)
Acrochordon and Fibroepithelial polyp are other names for this
Skin tag
Polypoid skin surrounded by normal appearing skin
Skin tag (Acrochordon, Fibroepithelial polyp)
Skin tags are frequently in these 3 locations
Neck, Axilla, Trunk of older people
Skin tags (acrochordon, fibroepithelial polyp) are associated with these 2 conditions
Obesity and Type II diabetes
Presence of skin tags (acrochordon, fibroepithelial polyp) may increase during this
Pregnancy
Cutaneous cyst involving a plugged hair follicle, often seen as punctum
Epidermal inclusion cyst
Cutaneous cyst that is lined by stratified squamous epithelium with granular layer
Epidermal inclusion cyst
Cutaneous cyst where some form by implantation of epithelium into dermis
Epidermal inclusion cyst
Cutaneous cyst that is mostly found on scalp/head
Pilar (trichilemmal) cyst
Cutaneous cyst that is lined by stratified squamous epithelium with abrupt keratinization
Pilar (trichilemmal) cyst
Cutaneous cyst with no punctum
Pilar (trichilemmal) cyst
Does Pilar (trichilemmal) cyst have a punctum?
No
Does Epidermal inclusion cyst have a punctum?
Often yes
Cutaneous cysts are filled with what type of material?
Keratinaceous
Hyperkeratotic dysplastic lesion on sun-damaged skin
Actinic Keratosis
Condition involving white, scaly, papules or macules
Variable size but usually less than 1cm
Actinic Keratosis
What is the typical patient with Actinic Keratosis?
Usually elderly, fair skinned
Does Actinic Keratosis involve sun damaged skin?
Yes
Basal layer squamous atypia and dermis with Solar Elastosis are seen in this condition
Actinic Keratosis
Condition of Actinic Keratosis of lower lip
Scaly, thin skin
Erythema, Leukoplakia
Actinic Cheilitis
Condition that is similar to Actinic Keratosis but involves full thickness keratinocyte atypia
Squamous cell carcinoma in situ (Bowen Disease)
Is Squamous cell carcinoma in situ (Bowen Disease) related to sun damaged skin?
Mostly but not exclusively
Squamous cell carcinoma in situ (Bowen Disease) may arise de novo or from this condition
Actinic Keratosis
Squamous cell carcinoma in situ (Bowen Disease) is increased in this type of patient
Immunocompromised
Full thickness keratinocyte atypia is morphologically seen in this condition
Squamous cell carcinoma in situ (Bowen Disease)
Is there dermal invasion in Squamous cell carcinoma in situ (Bowen Disease)?
No
What is the main difference between Actinic Keratosis and Squamous cell carcinoma in situ (Bowen Disease)?
Squamous cell carcinoma in situ (Bowen Disease) involves full thickness keratinocyte atypia
Invasive tumor of keratinocytes into dermis
Invasive squamous cell carcinoma
Is there dermal involvement in Invasive squamous cell carcinoma?
Yes, it is an invasive tumor of keratinocytes into dermis
Keratin pearls are seen in this condition
Invasive squamous cell carcinoma
Desmoplasia is seen in this non-pigmented lesion
Invasive squamous cell carcinoma
Is Invasive squamous cell carcinoma related to sun damaged skin?
Sun exposed skin is most common
Condition that is very similar to Actinic Keratosis and Squamous cell carcinoma in situ but may ulcerate and may have mass or nodularity
Invasive squamous cell carcinoma
Non-pigmented lesion that occurs often with Squamous cell carcinoma in situ, and also involves ulceration and hyperkeratosis
Invasive squamous cell carcinoma
Solar Elastosis of the dermis is seen in this condition
Actinic keratosis
Non-pigmented lesion that is increased in immunocompromised patients and also seen with chronic ulcer, scar, burn sites
Invasive squamous cell carcinoma
Scaly, red, macule/papule that may ulcerate and have mass or nodularity is seen in this non-pigmented lesion
Invasive squamous cell carcinoma
Non-pigmented lesion involving detached nests of atypical keratinocytes, desmoplastic stroma, and keratin pearls if well-differentiated
Invasive squamous cell carcinoma
Invasive squamous cell carcinoma has a poor prognosis in these 2 situations
Deeply invasive or on lip
Do Invasive squamous cell carcinoma metastasize?
Rarely
Malignant neoplasm of basal keratinocytes
Basal cell carcinoma
Do Basal cell carcinomas metastasize?
Almost never
Non-pigmented lesion that is a pearly papule with rolled borders, often with telangiectatic vessels, often ulcerate, and slow progressive locally destructive invasion
Basal cell carcinoma
Dark, basophilic basal layer that descends into the dermis and outer nuclei showing peripheral palisading are seen in this non-pigmented lesion
Basal cell carcinoma
Small, firm dermal nodule often with overlying hyperpigmentation that may occur anywhere on adults
Benign fibrous histiocytoma (Dermatofibroma)
Where does Benign fibrous histiocytoma (Dermatofibroma) occur on the body?
Anywhere on adults; commonly on legs of young to middle age women
Pinch sign is seen in this dermal tumor
Benign fibrous histiocytoma (Dermatofibroma)
Dermal tumor that is well-defined, unencapsulated, may touch subcutaneous fat but not invade, made of spindled cells with “entrapped” collagen, and may have epidermal hyperplasia with pigmentation
Benign fibrous histiocytoma (Dermatofibroma)
Dermal tumor that may touch subcutaneous fat but not invade
Benign fibrous histiocytoma (Dermatofibroma)
Well-differentiated fibrosarcoma of skin that begins as dermal plaque
Dermatofibrosarcoma Protuberans (DFSP)
Dermatofibrosarcoma Protuberans (DFSP) most often occur in this part of the body
On trunk of adults
IHC marker for Dermatofibrosarcoma Protuberans (DFSP)
CD34+
CD34+ by IHC indicates this dermal tumor
Dermatofibrosarcoma Protuberans (DFSP)
Dermal tumor that involves cellular proliferation of fibroblasts, similar to dermatofibroma, and extends into deep subcutis
Dermatofibrosarcoma Protuberans (DFSP)
How far does Dermatofibrosarcoma Protuberans (DFSP) extend in the skin?
Into deep subcutis
How far does Benign fibrous histiocytoma (Dermatofibroma) extend into the skin?
May touch subcutaneous fat but does not invade
This type of growth in Dermatofibrosarcoma Protuberans (DFSP) gives multi-nodularity
Downward growth
Histological pinwheel pattern is seen in this dermal tumor
Dermatofibrosarcoma Protuberans (DFSP)
Marker present on all lymphocytes
CD45
CD45 is a marker on these cells
All lymphocytes
Tryptase and CD117 are markers for this type of cell
Mast cell
2 makers for Langerhans cells
S100 and CD1a
Condition where malignant epidermotropic CD4+ T cells infiltrate skin
Mycosis fungoides
Peak age of Mycosis fungoides patient
40’s
Is Mycosis fungoides associated with sun exposed areas?
No, involves non-sun exposed areas
Pautrier microabscess is seen in this lesion
Mycosis fungoides
Aggregates of atypical CD4+ T cells within the epidermis that are indicative of mycosis fungoides
Pautrier microabscess
What does a Mycosis fungoides lesion in the patch stage look like?
Red and scaly
What does a Mycosis fungoides lesion in the plaque stage look like?
Red, brown scaling plaques
Condition associated with the leukemic phase of Mycosis fungoides
Invovles generalized erythroderma, lymphadenopathy
Sezary syndrome
Circulating lymphocytes with cerebriform nuclei are seen in this condition
Sezary syndrome associated with Mycosis fungoides
Epidermotropic CD4+ T cells are seen in this lesion
Mycosis fungoides
What type of T cells are seen in Mycosis fungoides?
CD4
Accumulation of mast cells in dermis
Cutaneous mastocytosis
In Cutaneous mastocytosis, there is an accumulation of mast cells in this skin layer
Dermis
Term that describes an isolated Cutaneous mastocytosis lesion
Mastocytoma
What age does Cutaneous mastocytosis present?
Birth to middle age
>50% are early childhood; may be congenital, usually present by 2 eyars
Genetic driver mutation in Cutaneous mastocytosis
c-kit
Common generalized form of Cutaneous mastocytosis
Urticaria pigmentosa
What is the difference between childhood and adult onset Cutaneous mastocytosis?
Mostly limited to skin in children, often with spontaneous resolution by adulthood
Adult onset tends to persist as chronic disease with dissemination
Darier’s sign is seen in this condition
Cutaneous mastocytosis
Levels of serum tryptase in Cutaneous mastocytosis
Elevated
2 IHC markers for Cutaneous mastocytosis
Tryptase and CD117 (c-kit)
Tryptase is elevated in this non-pigmented lesion
Cutaneous mastocytosis
Urticaria pigmentosa is the more common generalized form of this non-pigmented lesion
Cutaneous mastocytosis
What is Darier’s sign?
When a lesion welts up after rubbing it due to histamine release
Seen in Cutaneous mastocytosis
Type of xanthoma:
Crops of yellow papules
Extensor surfaces and buttocks
Associated with Hypertriglyceridemia
Eruptive
Type of xanthoma:
Deposits over elbows/knees
Associated with Hypercholesterolemia > Hypertriglyceridemia
Tuberous
Type of xanthoma:
Usually Achilles tendon or hands, knees, elbows
Associated with Familial Hypercholesterolemia
Tendinous
Type of xanthoma:
Flat deposits on palms and flexural folds
Dysbetalipoproteinemia
Familial Hypercholesterolemia
Planar
Type of xanthoma:
Eyelids
>50% have normal lipids, more predictive if young
Xanthelasma
Xanthoma on the eyelids
Xanthelasma
Dermal infiltration with foamy macrophages is the morphological finding of this non-pigmented lesion
Xanthomas
What layer of skin is infiltrated in a xanthoma?
Dermis
Dermal infiltration of this type of cell is seen in Xanthomas
Foamy macrophages