Sandbox:Roukoz

Diseases		Physical exam					Para-clinical findings			Additional findings
		Skin Examination
							Diagnosis
		Type	Color	Texture	Size	Distribution	Dermoscopic Findings	Histopathology	Unique features
Cutaneous squamous cell carcinoma	SCC in situ (Bowen's disease)	Scaly patch or plaque	Erythematous Skin colored	Scaly		Fair-skinned individuals: sites frequently exposed to the sun In black individuals: legs, anus, areas of chronic inflammation		Keratinocytic dysplasia involving the full thickness of the epidermis No infiltration into the dermis Pleomorphic keratinocytes Hyperchromatic nuclei	Fair-skinned individuals: sites frequently exposed to the sun In black individuals: legs, anus, areas of chronic inflammation	Grows slowly, enlarging over the course of 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: sites frequently exposed to the sun In black individuals: legs, anus, areas of chronic inflammation	White circles Keratin Blood spots White structureless zones	Keratinocytic dysplasia involving the full thickness of the epidermis No infiltration into the dermis Pleomorphic keratinocytes Hyperchromatic nuclei		May be painful or pruritic
Keratoacanthoma		Small macule initially Papular and eventually forms a circumscribed nodule May have telangiectasias	Skin-colored Mildly erythematous	Prominent keratinous core in the center of the nodule		Sun-exposed areas Usually face (especially the eyelids, nose, cheek, and lower lip), neck, hands, and arms	White circles Keratin Blood spots White structureless zones	Well-differentiated squamous epithelium showing mild degrees of pleomorphism and forming masses of keratin that constitute the central core Epidermal hyperplasia with large eosinophilic keratinocytes Inflammatory infiltrate in the dermis		Rapid growth (within weeks)
Merkel cell carcinoma		rapidly growing, painless, firm, nontender, shiny, flesh-colored or bluish-red, intracutaneous nodule	No more additional findings	Older patients with light skin tones	No more additional findings	Starts on areas of skin exposed to the sun Most frequent locations for the primary tumor are head and neck, upper limbs and shoulder, lower limbs and hip, and trunk	Milky red areas; linear, irregular vessels; and polymorphous vessels	Strands or nests of monotonously uniform, round, blue cells, containing large basophilic nuclei with powdery dispersed chromatin and inconspicuous nucleoli, and minimal cytoplasm Single-cell necrosis, frequent mitoses, lymphovascular invasion, perineural invasion, and epidermal involvement via pagetoid spread.		Blue-red, dome-shaped nodule
Basal cell carcinoma	Nodular basal cell carcinoma	Pearly papule with telangiectasias	Pink or flesh-colored papule	none	No more additional findings	Typically presents on the face				Ulceration is frequent, and the term "rodent ulcer" refers to these ulcerated nodular BCCs May have a "rolled" border, where the periphery is more raised than the middle.
	Superficial basal cell carcinoma	Scaly patch	Erythematous lesion		No more additional findings			large, hyperchromatic, oval nuclei and little cytoplasm well differentiated and cells appear histologically similar to basal cells of the epidermis
Prurigo nodules		Firm, dome-shaped and itchy	ranging in size from a few millimeters to several centimeters and often symmetrically distributed	none	Nodules can be flesh-colored, erythematous, or brown/black	Extensor surfaces of the arms and legs and on the trunk Upper back, abdomen, and sacrum		Thick, compact orthohyperkeratosis Irregular epidermal hyperplasia or pseudoepitheliomatous hyperplasia Focal parakeratosis with irregular acanthosis Diminished nerve fiber density A nonspecific dermal infiltrate containing lymphocytes, macrophages, eosinophils, and neutrophils		Nodules range in number from few to hundreds upper midback area is usually spared Worsened by heat, sweating, or irritation from clothing
Common nevus		Dome-shaped, usually nonpigmented or hypopigmented nodules with a smooth surface	Terminal hairs are often present				Comma-shaped or curved vessels Structureless skin-colored to light brown background pigmentation Residual brown globules (clods) or brown thick circles, mainly located around the hair follicles can sometimes be seen
Blue nevus		Bluish macules or papules				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			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				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)
	Lentigo maligna melanoma
	Superficial spreading melanoma
	Nodular melanoma								Cells proliferate downwards through the skin (vertical growth)	Two-thirds arise in normal skin, the rest in existing moles Genetic component in some cases with a positive family history
	Acral lentiginous melanoma
	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
Lichen planus-like keratosis
Seborrheic keratosis
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.