Skin Pathology I Flashcards
What is Vitiligo?
Chronic depigmenting condition from destruction of epidermal melanocytes
Autoimmune
Associated with pernicious anemia and Hashimoto’s thyroiditis
How does Vitilgo present?
Asymptomatic white patches that appear in acral areas and orifices (but can present anywhere)
Acquired during childhood or early adulthood
What is a freckle?
Flat, brown macules
Results from basal layer hyperpigmentation
Darken with sun exposure
What is lentigo?
Small pigmented macules that appear in older patients as a result of skin exposure
What are benign melanocytic nevi?
Small, uniformly pigmented macules
What is a junctional melanocytic nevus?
Melanocytic nests at the dermal-epidermal junction
None reside in the dermis
What is a compound melanocytic nevus?
Junctional and dermal nests of nevus cells
Results in more raised and dome shaped nevus than junctional
With increasing dermal depth, nevus cells become smaller - sign of benign lesion
What is a dermal melanocytic nevus?
All nests reside in the dermis
Causes a raised papule with little to no pigment
What is a Spitz nevus?
Deep red color, common in children
Unique histologic features
What are Kamino bodies?
Eosinophilic collection of basement membrane material
Associated with Spitz Nevus
What is a dysplastic melanocytic nevus?
Commonly larger, oval and multiple with irregular pigment borders
Irregular proliferation of melanocyti nests along junction with melanocyte atypia
What is dysplastic nevus syndrome?
Patients display multiple dysplastic nevus
AD
High-risk for development of malignant melanoma
What is melanoma?
Malignancy of melanocytes
Develops de novo or from a pre-existing nevus
Number one cause of skin cancer deaths worldwide
What are the radial and vertical growth phases of melanoma?
Radial - horizontal spread within the epidermis and papillary dermis
Vertical - tumor cells invade downward into deeper dermal layers
What is superficial spreading melanoma?
Most common
Typically on sun-exposed skin
Lesions may be multiple shades of red
What is lentigo maligna?
Melanoma subtype that typically prevents on the face of older patients
Slow-growing, long radial growth phase
Predominantly junctional growth of atypical melanocytes
What is acral lentiginous melanoma?
Least common, but most common inf african and asian descent
Melanoma occurs on palms, soles, and beneath nail plate
What is nodular melanoma?
Highly atypical melanomas that occur in the dermis, no radial growth phase - only vertical
Darkly pigmented nodules
What is the breslow thickness?
Tumor thickness measurement from the skin surface
Most closely correlates with survival statistics
What are the excision guidelines for tumors?
In situ - 0.5 cm margin
Tumor < 1 mm, 1 ccm margin
What is seborrheic keratosis?
Most common benign tumor in oder individuals
Light brown, flat macules
Tumor of keratinocytes
What is the sign of Leser-Trelat?
Multiple eruptive seborrheic keratoses
Associated with internal malignancy
What is acanthosis nigricans?
Hyperpigmentation and thickening of the skin folds
May signal an underlying disorder like endocrine (DM)
What is an epidermal inclusion cyst?
Aka sebaceous cyst
Derived from hair follicles
Granulomatous inflammation when ruptured
What is actinic keratosis?
Earlies identifiable lesion that can develop into squamous cell carcinoma
Erythematous scaly papules on sun-exposed skin
What are the histologic features of actinic keratosis?
Parakeratosis in stratum corneum
Hyperplasia and cytoligic atypia of lower third
What is the most common nonmelanoma skin cancer?
Basal cell carcinoma
Followed by squamous cell carcinoma
What is Bowens disease?
Squamous cell carcinoma in situ
Confined to the epidermis and do not break the basement membrane
What is erythroplasia of Queyrat?
Bowens disease specifically of the glans penis
How does Bowens disease present?
Scaly pink plaque or a thin keratotic papule on the sun-exposed skin
How does invasive squamous cell carcinoma present?
Raised, firm, pink-to-flesh colored keratotic papule or plaque
Penetrate the dermis
Metastasizes to regional lymph nodes <5%
What is a keratoacanthoma?
Variant of squamous cell carcinoma
Erythematous nodule with central keratin filled crater (volcani)
What is basal cell carcinoma?
Most common cutaneous malignancy
Pearly papule with telangiectasia
Can cause local destruction and disfigurement if neglected or inadequately treated
What is nodular basal cell carcinoma?
Most common type
Waxy papules with central depression, pearly appearance with telangiectasia
What are the histological features of BCC?
Nestsof basaloid cell swhich palisade at the border of the nest
Nests in fibromyxoid stroma
What is Gorlin-Goltz syndrome?
Nevoid basal cell carcinoma syndrome
Autosomal dominant - mutation in PTCH gene
Abnromal facies, multiple BCCs, skeletal abnormalities
What is a dermatofibroma?
Benign lesion that most often occurs on the lower legs
Benign dermal proliferation of fibroblasts
Displays the “dimple-sign” in whicch it depresses when squeezed (as opposed to a mole)
What is Icthyosis?
Disorders of epidermal maturation
Most cases are congenital
Acquired - Icthyosis vulgaris
What is ichthyosis vulgaris associated?
Lymphoid and visceral malignancies
Paraneoplastic syndrome
