Sandbox:Roukoz

Diseases		Skin examination					Diagnosis		Additional findings
		Type	Color	Texture	Size	Distribution	Dermoscopic Findings	Histopathology
Cutaneous squamous cell carcinoma	SCC in situ (Bowen's disease)	Patch Plaque	Erythematous Skin colored	Scaly	Variable	Fair-skinned individuals: sun-exposed areas In black individuals: legs, anus, and areas of chronic inflammation	Presence of dotted and/or glomerular vessels White to yellowish surface scales Red-yellowish background	Keratinocytic dysplasia of the epidermis No infiltration into dermis Pleomorphic keratinocytes Hyperchromatic nuclei	Slow growth over the years
	Invasive squamous cell carcinoma	Papules Plaques Nodules	Skin colored	Indurated or firm, and hyperkeratotic (well-differentiated lesions) Soft with ulceration or hemorrhage (poorly differentiated lesions)	0.5 to 1.5 cm	Fair-skinned individuals: sun-exposed areas In black individuals: legs, anus, and areas of chronic inflammation	White circles White structureless areas Masses of keratin Hairpin and linear-irregular vessels	Keratinocytic dysplasia of the epidermis No infiltration into dermis Pleomorphic keratinocytes Hyperchromatic nuclei	May be painful or pruritic
Keratoacanthoma		Macules Papules May have telangiectasias	Skin-colored Mildly erythematous	Prominent keratinous core in the center of the nodule	1 to 2.5 cm	Sun-exposed areas Face, neck, hands, and arms	White circles Keratin Blood spots White structureless zones	Well-differentiated squamous epithelium Central keratin core Epidermal hyperplasia with large eosinophilic keratinocytes Inflammatory infiltrate in the dermis	Rapid growth (within weeks)
Merkel cell carcinoma		Intracutaneous nodule	Shiny Flesh-colored or bluish-red	Firm	Rapidly growing	Starts on Sun-exposed areas Head and neck Upper limbs and shoulder Lower limbs and hip Trunk	Milky red areas Linear Irregular vessels Polymorphous vessels	Strands of uniform, blue cells, with large basophilic nuclei Single-cell necrosis Frequent mitoses Lymphovascular invasion Perineural invasion Epidermal involvement via pagetoid spread	Usually in older individuals with light skin tones
Basal cell carcinoma	Nodular basal cell carcinoma	Papule	Flesh-colored		Variable	Face	Focused, bright red, and branching arborizing vessels Loosely arranged blue-gray dots		May have a "rolled" border
	Superficial basal cell carcinoma	Patch	Erythematous	Scaly	Variable		Shiny white to red, translucent or opaque structureless areas Multiple small erosions	large, hyperchromatic, oval nuclei and little cytoplasm well differentiated and cells appear histologically similar to basal cells of the epidermis
Prurigo nodules		Dome-shaped nodules	Flesh-colored Erythematous Brown/black	Firm	Few millimeters to several centimeters	Extensor surfaces of the arms and legs and on the trunk Upper back, abdomen, and sacrum		Thick, compact orthohyperkeratosis Irregular epidermal hyperplasia Focal parakeratosis with irregular acanthosis A nonspecific dermal infiltrate containing WBCs	Nodules range in number from few to hundreds Worsened by heat, sweating, or irritation from clothing
Common nevus		Dome-shaped nodules	Hypopigmented	Smooth surface Terminal hairs often present	Variable		Comma-shaped or curved vessels Structureless light brown background Residual brown thick circles around the hair follicles
Blue nevus		Macules Papules	Blue		Variable	Head and neck, Dorsal aspect of the distal extremities Sacral area	Structureless blue pigmentation Structureless blue and white or blue and brown on some occasions
Spitz nevus	Nonpigmented Spitz nevus	Nodules	Pink		Variable	Cheek	Coiled vessels White network over a pink to reddish background		Most commonly develops in children, adolescents, and young adults.
	Reed-like Spitz	Papule	Heavily pigmented		Variable		Structureless black to gray center Hypopigmented follicular openings Peripheral streaks Pseudopods Globules		Most commonly develops in children, adolescents, and young adults.
Melanoma	Melanoma in situ (Lentigo Maligna)	Macule	Variable (from light to dark brown, black, pink, red, or white)	Smooth	Around 1 cm	Sun-damaged skin of the head or neck	Asymmetric, pigmented follicular openings Gray angulated lines Gray areas, dots, and globules Circle within a circle	↑ atypical spindle shaped melanocytes, Arranged in single cells or in small nests along the dermoepidermal junction	Development of darker pigmentation, sharper borders, or nodular areas are signs of progression to lentigo maligna melanoma
	Lentigo maligna melanoma	Macule	Brown/tan	Freckle-like	Variable	Chronically sun-damaged areas	Asymmetric, pigmented follicular openings Gray angulated lines Gray areas, dots, and globules Circle within a circle	"Star-burst giant cells" at the basal layer of the epidermis Poorly cohesive or dyshesive nests along the dermal-epidermal junction forming the "swallow's nest" sign Cytoplasm is shrunken and surrounds a pale nucleus with small nucleoli	Usually in older individuals
	Superficial spreading melanoma	Macule Plaque with irregular borders	Variably pigmented (red, blue, black, gray, and white)	Thin	1 mm to > 1 cm	Anywhere but most commonly: Back (men and women) Lower extremities (women)		Asymmetric Poorly circumscribed Lack cellular maturation	Lateral (radial) growth before vertical (invasive) growth
	Nodular melanoma	Polypoid nodule	Dark color		Variable			Cells proliferate downwards through the skin Dermal growth in isolation or in association with an epidermal component	Two-thirds arise in normal skin, the rest in existing moles
	Acral lentiginous melanoma	Macules Patches	Dark brown to black	Raised areas Ulceration Bleeding	Variable	Palmar Plantar Subungual Mucosal surfaces			Most common among dark skinned individuals
	Amelanotic melanoma	Color usually pink, purple or normal skin color	Usually have an asymmetrical shape with an irregular border		Red, nonspecific lesion with slightly elevated borders				Do not make melanin, so lesions are not pigmented
Solar lentigo		Multiple spots	Brown		Around 5mm		Faint pigmented fingerprint structures Structureless pattern Light brown pseudonetwork with well-defined borders and a "moth-eaten" edge	↑ melanin deposition in keratinocytes ↑ linear arrangement of melanocytes at the dermoepidermal junction.	Associated with UV exposure and skin aging
Sebaceous hyperplasia		Papules	Skin-colored to brownish	Umbilicated	2 - 6 mm	Forehead Nose Cheeks	Structureless yellow to whitish center surrounded by short linear "crown vessels"		Usually in middle-aged or older patients
Lichen planus-like keratosis		Papule Plaque	Gray to brown		Variable		Shows a coarse or fine, gray to blue, granular pigmentation Diffuse brownish gray granules
Seborrheic keratosis					Variable
Actinic keratosis		less pigmentation, and tend to be somewhat smaller in size.	Erythema		Hyperkeratosis				painful

SCC in situ: Frequently, there is associated thickening of the epidermis (acanthosis), as well as hyperkeratosis and parakeratosis of the stratum corneum. In contrast to SCC in situ, actinic keratoses demonstrate only partial-thickness epidermal dysplasia.