Introduction Highly aggresive skin malignancy of melanocytic origin Comprises 3% of skin cancers and 65% of skin-cancer related deaths Risk factors include blistering sunburns family history >3 sunburns before age 20 tanning booth use xeroderma pigmentosa large number of nevi dysplastic nevi-precursor lesions Subtypes superficial spreading (most comon) - longer radial growth phase nodular - rapid vertical growth phase lentigo maligna (rare) - common in dark skinned individuals acral lentiginous - common in dark skined individuals, located on palms of hands, soles of feet, nail beds. Bob marley died of this. amelanotic - lack pigment desmoplastic (most aggressive) Presentation Often presents with complaints of a pigmented lesion that has recently changed shape or size Suspicion for melanoma increased by presence of ABCDE's Asymmetry - asymmetric lesions Border irregularity - irregular, indistinct, or blurred margin Color variation - multiple colors within a single lesion or pigment variation within the same lesion Diameter - lesions > 6mm (about the size of the head of a pencil eraser) are higher risk Evolution - change in a pre-existing lesion or development of a new lesion. if present, this is the most concerning feature Evaluation Excisional biopsy unless lesion is large and would leave substantial deficit, then punch biopsy the junction of abnormal and normal skin do not shave biopsy lesions with suspicious characteristics (ABCDE's), depth is important in deiciding treatment Further workup no routine labs or imaging recommended select imaging based on presence of physical exam and history findings Biospsy shows melanocytes with marked cellular atypia invasion into the dermis vacuolated cytoplasm hyperchromatic nuclei with prominant nucleoli Differential Nevi Seborrheic keratosis Freckles/Ephelids Lentigines Basal cell carcinoma Treatment Wide surgical excision margins guided by Breslow depth Metastatic melanoma: potential surgical removal of metastasis immunotherapy based on presence of absence of V600BRAF mutation Cutaneous melanoma: Indications for lymph node dissection Depth >1 mm Palpable lymph node Prognosis, Prevention, and Follow-Up Prognostic Indicators breslow depth - most important mitotic figures/growth rate presence of ulceration recurrence Prevention Sun protection (sunscreen, clothing with sun protective factors) Regular "skin checks" for any new or changing lesions Follow-up Every 3 mos x 1 year Every 6 mos x 2-5 years Annually x 5 years and beyond