Neoplasms of the Skin Flashcards
Seborrheic keratosis age affected
Older individuals
Seborrheic keratosis benign or malignant neoplasm
Benign (no malignant potential)
Seborrheic keratosis clinical description
Flat-topped to exophytic papules, “warty” and “stuck-on”, range from light tan/pink to dark brown/gray, no true pigment pattern
Seborrheic keratosis cell type affected
Keratinocytes
Seborrheic keratosis histology
Lesion extends to a uniform depth in a parallel line to the epidermal surface underlying the lesion (String sign), keratinocytes lack atypic and mitoses, prominent horn cysts
Nevus definition
AKA “mole” or “birthmark”, any of various congenital or acquired lesions of the skin or oral mucosa that are usually pigmented and raised and may include epidermal, melanocytes, connective types of tissue
Nevus histology
Described by which portion of the skin is involved, epidermis (junctional), epidermis and dermis (compound), or dermis (intradermal melanocytic)
Nevus benign characteristics
Symmetric lesion, melanocytes mature with descent (superficial cells are larger, pigmented, well-nested, while deeper cells are smaller, nonpigmented, less nested), melanocytes show no or minimal cytologic atypia, mitotic activity rarely present
Benign pigmented lesion clinical characteristics
Symmetric, distinct border, homogenous color, small, stable/unchanging
Basal cell carcinoma clinical features
On sun exposed skin, “pearly” or shiny appearance, papule with substance, telangectasias, erosion/ulceration, bleed easily with minimal trauma, rolled borders
Basal cell carcinoma histology
Nests of basaloid cells (islands) with peripheral stromal clefting, palisading nuclei, mucin
Basal cell carcinoma prognosis
Locally aggressive, rarely metastasize
Basal cell carcinoma pathogenesis
Related to sun exposure, may be related to genetic factors
Actinic keratosis histology
Solar elastosis (blue-gray appearance of epidermis from sun exposure), parakeratosis, atypia of basal keratinocytes (large, occupying lower portions of epidermis)
Actinic keratosis prognosis
Premalignant lesion, about 10% progress to squamous cell carcinoma if untreated
Squamous cell carcinoma in situ clinical features
Relatively well defined, crusted, erythematous (pink), scaly, thin plaque on sun exposed areas with no erosion, ulceration or marked thickening
Squamous cell carcinoma in situ prognosis
Invasive carcinoma in 8% if untreated, spontaneous regression possible
Squamous cell carcinoma in situ other names
SCCIS, Bowen’s disease
Squamous cell carcinoma in situ histology
Parakeratosis, acanthuses, atypical keratinocytes (full thickness involvement of the epidermis and sometimes pilosebaceous epithelium), pale or vacuolated keratinocytes possible, disorderly maturation of epidermis, loss of granular layer, intraepidermal mitoses, perivascular lymphocytes
Squamous cell carcinoma clinical characteristics
Red papule, nodule or plaque, scaly, often ulcerated, may have hemorrhagic crusting
Squamous cell carcinoma prognosis
More likely to metastasize, especially if left untreated
Squamous cell carcinoma predisposition
Sun damaged areas, scars, irradiated or chronically infected/irritated sites, lichen sclerosis, lichen planus, discoid lupus, xeroderma pigmentosum, organ transplant recipients
Melanoma histology
Asymmetric, abnormal maturation, mitoses present, atypia of cells (melanocytes large with prominent nuclei and increased cytoplasm, located in all layers of epidermis), pagetoid spread
Melanoma clinical characteristics
Asymmetric lesion with uneven borders, multiple colors, larger than pencil eraser, changing in size, share, and/or color
Nevus vs melanoma histology - symmetry
Nevus - symmetric, melanoma - asymmetric
Nevus vs melanoma histology - cell maturation
Nevus - matures with depth, melanoma - does not mature with depth
Nevus vs melanoma histology - mitoses
Nevus - rare or absent mitoses, melanoma - mitoses present
Nevus vs melanoma histology - atypia
Nevus - absent cytologic atypia, melanoma - cytologic atypia
Nevus vs melanoma histology - pagetoid spread
Nevus - absent pagetoid spread, melanoma - prominent pagetoid spread
Most important histopathologic feature for melanoma prognosis
Depth of invasion (Breslow level)
Breslow depth vs prognosis
The lower the depth the lesion, the lower the survival rate
Melanoma mutation
BRAF V600E (proto-oncogene, normally makes B-Raf, important in signal transduction)
Melanoma possible treatment
Targeted therapy by inhibiting BRAF kinase in metastatic or unresectable melanoma
Skin cancer etiology
Formation of thymine dimers from UVB radiation exposure (consequence of DNA damage)
Xeroderma pigmentosum definition
Rare, autosomal recessive genodermatosis
Nevoid basal cell carcinoma syndrome
AKA Gorlins, PTCH mutation, develop extensive basal cell carcinomas, need to avoid radiation, odontogenic keratocyts and skeletal abnormalities associated
Dysplastic nevus syndrome
AKA atypical mole syndrome, cutaneous condition characterized by unusual nevi and multiple inherited melanomas, CDKN2A gene mutations
Squamous cell carcinoma histology
Squamous differentiation evident with keratinocytes pearls
