what is a benign lesion and what are its characteristics?
abnormal growth of cells that lack the ability to invade neighboring tissues or metastasize uniform, smooth or papillary and can displace normal structures
what is a malignant lesion and what are its characteristics?
cancerous cells that invade and destroy body tissues irregular borders, vascularization/telangiectasia, ulceration and bleeding, alteration or normal architecture, loss of cilia and irregular pigmentary changes
what is a metastatic lesion and what are the characteristics?
cancerous cells that spread from a primary site to tissue not directly adjacent to the primary site spread via blood stream or lymph
what is seborrheic keratosis and what causes it?
benign pigmented cutaneous lesion - no malignant potential caused by proliferation of basal cells (immature keratinocytes)
who typically gets seborrheic keratosis and how does it present?
sun exposure, age, genetics onset in 30's - more common in patients over 50 present in hair-bearing areas of skin (chest, face, back - not palms or soles)
what are the characteristics of a seborrheic keratosis?
usually solitary lesion 1-2cm, moveable hyperpigmented plaque, elevated with waxy surface and sharp demarcation
what is the treatment for a seborrheic keratosis?
obervation and cryotherapy, laser therapy or excision if they bother the patient
what syndrome is associated with seborrheic keratosis?
leser-trelat syndrome = sudden onset of multiple SK's - usually onset of internal malignancy (stomach, liver, colon, pancreas cancers)
what is squamous papilloma?
benign hyperplasia of squamous epithelium flesh colored with cerebriform surface (pedunculated or sessile)
who typically presents with squamous papilloma?
middle-aged and elderly patients (gradual onset and slow growth)
what are some differential diagnoses for squamous papilloma?
basal cell carcinoma, seborrheic keratosis, and verruca vulgaris (* all benign tumors of the epidermis)
what is verruca vulgaris?
squamous papilloma caused by the human papilloma virus - can have concomitant conjunctivitis multiple lesions
who typically gets verruca vulgaris?
immunocompromised patients, children and young adults
what is the treatment for verruca vulgaris?
observation, complete surgical excision or cryotherapy - usually spontaneous resolution
what is molluscum contagiosum?
viral infection of the skin - multiple pearly flesh colored lesions with a small central crater
who typically gets molluscum contagiosum?
common in children suspect immunocompromised state if present in adults or severe bilateral involvement in children
what is the transmission of molluscum contagiosum?
pediatric = direct contact adult = STD
what is the treatment for molluscum contagiosum?
incision and expression, cryotherapy, excision or laser treatment - recurrence is rare after complete resolution
what condition is molluscum contagiosum associated with?
chronic follicular conjunctivitis
what is keratoacanthoma?
a pre-malignant tumor of the epidermis, develops on hair-bearing sun exposed skin (85% on face and 5% on eyelids)
who typically gets keratoacanthoma?
males > females and greater prevalence in immunosuppressed patients (s/p renal transplantations)
what are the characteristics of keratoacanthoma?
elevated margins with central crater, usually solitary lesion, rapid onset/growth, spontaneous regression
what is the histopathology for keratoacanthoma?
well differentiated squamous cells with keratin-containing center
what are some risk factors for keratoacanthoma?
skin color, UV radiation, trauma and genetics - may be a clinical variant of squamous cell carcinoma
what is the treatment for keratoacanthoma?
observation and complete removal via surgical excision
what is actinic keratosis?
most common pre-cancerous cutaneous lesion - caused by proliferation of atypical keratinocytes
who typically gets actinic keratosis?
light-skinned, F > M, mean age is 62, UV exposed skin
where is actinic keratosis usually located?
face, eyelids, dorsa of hands and bald areas on men
what can actinic keratosis progress to if untreated?
20% progression to squamous cell carcinoma
what does actinic keratosis look like?
multiple, erythrmatous, sessile plaques, 1-10mm, pink in color but can be pigmented, less distinct margins than seborrheic keratosis