Cutaneous Neoplasms Flashcards
1
Q
What are seborrheic keratoses?
A
- one of the most common cutaneous neoplasms
- develop in middle age or older patients
- brown/tan waxy papules and plaques with a “stuck on” warty appearance most commonly on face/trunk/upper extremities
2
Q
What is the Leser-Trelat sign?
A
Sudden onset of multiple seborrheic keratoses associated with internal malignancy (most commonly stomach cancer)
3
Q
What do seborrheic keratoses look like on histology?
A
- Hyperkeratotic, papillomatous and verrucous epidermis
- Horn and pseudo horn cysts (invaginations of keratin)
- Variable melanin pigmentation is present, accounting for the brown coloration seen clinically
4
Q
What is actinic keratosis?
A
- also known as solar keratosis; common lesions that develop as a result of chronic sun damage
- middle aged to elderly onset (esp with fair complexion)
- red or tan/brown macues with “gritty” sandpaper like scales
- some lesions regress or may remain stable
- 0.1-10% become malignant squamous cell carcinoma
5
Q
What does actinic keratosis look like on histology?
A
- Atypia of the basal layer of the epidermis
- Corneal layer is thickened with retained nuclei (parakeratosis)
- Loss of granular layer in some places
- Dermis contains thickened, blue-gray elastic fibers (solar elastosis), the result of chronic sun damage
6
Q
Describe the etiology/prevalence of squamous cell carcinoma
A
- common neoplasm in older individuals (40+); 20% of all skin cancers
- UV radiation is the most common cause (DNA damage)
- Other predisposing factors include;
- chronic ulcers
- old burn scars
- HPV (esp in head and neck)
- toxic exposure (radiation, arsenic)
- immunosuppression (esp in solid organ transplant)
- 1-5% risk of metastasis in low risk area (~20% in high risk area such as lip/mucosa)
7
Q
What are the clinical symptoms of squamous cell carcinoma?
A
- red scaly plaque
- risk of metastasis is related to the location and degree of invasion
- ~2-4% higher risk in immunosuppressed patients
8
Q
How does SCC differ when it becomes invasive?
A
- invasive lesions (5% of SCCs) tend to be nodular and may ulcerate
- roughly 30% of invasive SCCs have metastatic potential
- classified as invasive when the neoplastic cells break through the basement membrane
9
Q
What does SCC look like on histology?
A
- full-thickness dysplasia (characteristically involves the entire epidermis)
- disorganization of the epidermal architecture
- loss of maturation
- lack of polarity of cells
10
Q
What is keratoacanthoma?
A
- variant of squamous cell carcinoma
- pink papule/nodule with a central keratin plug that grows rapidly (period of 2-10 weeks)
- can cause extensive local destruction
- occurs mainly on sun damaged skin
- some lesions will resolve spontaneously (or can become very aggressive)
- multiple lesions may be present in immunocompromised patients
11
Q
What do keratoacanthomas look like on histology?
A
- exophytic lesions with an invaginating mass of keratinizing, well-differentiated squamous epithelium at the sides and bottom
- central keratin-filled crater that enlarges with the maturation and evolution of the lesion
- epidermis on either side of the lesion is thrown up into a well-formed collarette
- epithelium is typically characterized by well-differentiated, often pale-staining, eosinophilic, glassy cytoplasm showing a striking tendency towards keratinization
12
Q
Describe basal cell carcinoma
A
- most common human cancer
- secondary to chronic sun exposure/UV radiation
- slow growing tumor that rarely metastasizes (unless immunocompromised)
- can be locally destructive
- associated with dysregulation of the sonic hedgehog or PTCH pathway (30-40%)
13
Q
What does basal cell carcinoma look like on histology?
A
- several histologic variants
- multifocal growths originating from the epidermis (superficial type)
- nodular lesions growing downward into the dermis (nodular type) of variably basophilic cells with peripheral palisading.
- tumor cells are small and uniform with round, darkly staining nuclei and minimal cytoplasm
- characteristic clefting artifact between the tumor nodules and the stroma
14
Q
What are melanocytic nevi?
A
- An above normal amount of melanocyte in the epidermis
- acquired from sun exposure
- congenital at birth (can be severe/widespread and increase risk of melanoma)
15
Q
What are the histological classifications of nevi?
A
- junctional (epidermis only)
- compound (epidermis and dermis)
- intradermal (dermis only)
16
Q
What are dysplastic nevi?
A
- clinically and histologically distinctive
- clincially larger than acquired nevi (>0.5 cm), irregular shape and uneven color
- may occur sporadically or in a familial form
- patients with multiple dysplastic nevi have increased risk of melanoma
17
Q
What is dysplastic nevus syndrome?
A
- familial or sporadic
- familial variant is autosomal dominant (mutations in CDKN2A gene in 40% of cases)
- large number of dysplastic nevi (80+)
- increased incidence of melanoma
- patients can also develop other malignancies (e.g. pancreatic carcinoma)
18
Q
Contrast familial and sporadic dysplastic nevus syndrome
A
- sporadic
- lower number of nevi (2-10)
- lifetime risk of melanoma ~10%
- familial
- hundreds of nevi
- lifetime risk of melanoma approaches 100%
**both show identical histological features (may be junctional of compound)
19
Q
What is the prevalence of melanoma?
A
- represents 3% of all cutaneous malignancies
- 6th most common cancer in the US
- more common in white population… affects men and women equally
- most common on back in men
- most common on legs in women
- typically a disease of adulthood
21
Q
What are the clinical features of melanoma? (ABCDE)
A
- Asymmetry
- Borders (notched, uneven, or blurred)
- Color (uneven; shades of brown, tan, red, and black may be present… 3+ is concerning)
- Diameter (>6 mm)
- Evolving (change in color/size of the lesion)
22
Q
What are the growth phases of melanoma?
A
- Radial growth phase
- melanocytes will proliferate within the epidermis (in situ… NO metastatic potential at this stage)
- Vertical growth phase
- dermal invasion and potential for metastasis
- extent of this phase determines the biological behavior (Breslow thickness/depth of invasion is the most important prognostic indicator)
- lesions >1.7 mm have greater potential for metastasis, <1 mm rarely metastasize
25
Q
What does a melanoma look like on histology?
A
- radial growth phase= asymmetric population of melanocytes within the epidermis (located along the dermal epidermal junction)
- melanoma cells are large with abundant cytoplasm, often showing dusty melanin pigmentation… often show pleomorphic vesicular nuclei with prominent eosinophilic nucleoli
- vertical growth phase= cells in dermis that grow in poorly formed nests or individual cells as an expansile nodules. There is lack of melanocytic maturation at the base of the lesion
26
Q
What is mycosis fungoides?
A
- most common cutaneous lymphoma
- occurs in late adulthood with a male predominance
- usually presents as red or pink scaly patches
- stages of patch, plaque, and nodules
- usually chronic course although may become aggressive
28
Q
What is sezary syndrome?
A
- blood involvement of T cell lymphoma
- erythroderma (skin is diffusely red and scaly; sometimes misdiagnosed as chronic eczema)
- poor prognosis (survival 1-3 years)
29
Q
What does mycosis fungoides look like on histology?
A
- mature T-cells show a tendency to colonize the epidermis (epidermotropism), although this is more evident in the patch and plaque forms than in tumor-stage disease.
- infiltrate contains large cells with highly irregular, convoluted or cerebriform nuclei, known as Sézary or mycosis cells.
- presence of atypical lymphoid cells in an intraepidermal vesicle (the Pautrier microabscess) is typical
