Small to medium size
Benign
Malignant
Larger patches
Benign - common
Benign - rare
- Becker’s naevus (develop coarse dark hair)
- Speckled & lentiginous naevus (light brown background, darker macules within)
- Mongolian spot (dark-skinned races / blue-grey /sacral)
- Naevus of Ito (asiatics / blue-grey / shoulder)
- Naevus of Ota (as above, periorbital)
Note
Brown patches tend to be benign
Raised
Benign - common
Benign - rare
Malignant
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Depressed
Flat and smooth
Macule
Patch
Scaly or crusty
Benign
Pre-malignant / malignant
Pedunculated
Smooth, skin-coloured papules & nodules
Benign - common
- Benign melanocyitc naevus (common mole)
- Molluscum contagiosum (pearly / umbilicated centre / clustered)
- Milium (multiple / few mms / white)
- Keloid scar (upper trunk most common site)
- Pilomatricoma Benign and rare
- Appendageal tumours (often facial / can be single or multiple)
- Fibrous papule of the face (solitary / firm / nose most common site)
- Solitary circumscribed neuroma (solitary / firm skin-coloured papule / most commonly seen near muco-cutaneous junctions of face)
- Angiofibroma (multiple / snout area / tuberous sclerosis)
- Lymphangioma (frog spawn-like clustered pearly papules)
Malignant
- Solid BCC (pearly and translucent / telangiectatic)
Smooth red papules & nodules
Benign - common
- Angioma (soft and compressible / may have purple-black components)
Benign - rare
- Spitz naevus (red / mole-like / commoner in children and young adults)
- Foreign body reactions
- Mastocytoma (wheals when rubbed - Darier's sign)
- Desmoplastic naevus (similar in appearance to dermatofibroma)
- Xanthogranuloma ()
- Leiomyoma (painful / multiple)
Malignant
Malignant - rare
- Skin metastases (firm)
- B-Cell lymphoma /leukaemia cutis (purple nodules)
- Angiosarcoma (red-purple / peau d'orange effect)
- Kaposi’s sarcoma (purple)
- Dermatofibrosarcoma protuberans (irregular shape / flesh-red-blue)
- Atypical fibroxanthoma (males mailny / sun exposed areas / can ulcerate)
- Merkel cell tumour (rapidly growing nodule / sun exposed sites)
Large and deep seated
Benign
- Epidermoid ‘sebaceous’ cyst
- Trichilemmal cyst (syn. pilar cyst / scalp)
- Lipoma (soft and can be lobulated / overlying skin mobile /often multiple)
- Cutaneous neurofibromas (domed-shaped / soft and compressible)
- Dermoid cyst (uncommon / often present at birth / head and neck)
- Angioleiomyoma (rare / tender)
Malignant
- Sarcomas (rare / consider in any large, deep and poorly defined nodule)
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Widely distributed
The following skin lesions are widely distributed and should be considered at most sites:
- Viral wart (black punctate thrombosed capillaries)
- Seborrhoeic keratosis (waxy scale /cerebriform or stuck-on)
- Molluscum contagiosum (pearly / umbilicated / clustered)
- Benign melanocytic naevus (common mole)
- Melanoma (can affect any site including genitalia, mucosae and nails)
- Basal cell carcinoma (60 % head & neck / 25 % trunk - common site for superficial BCC / forearms and hands seldom involved)
- Blue naevus (dorsa hands & feet, forearms, face, sacral area)
- Lipoma (soft and can be lobulated / overlying skin mobile /often multiple)
- Neurofibroma (domed-shaped / soft and compressible)
- Spitz naevus (red and mole-like / face and legs most common sites / uncommon)
- Appendageal tumours (a few types associated with significant internal disease)
Sun exposed sites
The following should be considered when lesions arise on the head and neck, dorsal forearms / hands and lower legs -
- Ephelis (syn. freckle)
- Lentigo (brown-black, smooth
- Actinic keratosis (<1cm / flat / rough scale)
- Bowen’s disease (pink-red / grow slowly to rach several cms / rough surface scale)
- Cutaneous horns (horn-like)
- SCC (tumid, tender papule-nodule / can ulcerate)
- Keratoacanthoma (domed nodule / central keratin plug / bolstered edge)
- Disseminated superficial actinic porokeratoses (uncommon / multiple / flat /annular / distal limbs)
Upper body
Benign - common
Benign - rare
- Pilomatricoma (face and trunk / stony hard / deep-seated)
- Becker's naevus (shoulder to upper limb / large brown patch that develops course hair)
- Xanthogranuloma (uncommon / face, neck and upper trunk / red-yellow papule or nodule / often multiple)
- Naevus of Ito ( (asiatics / blue-grey / shoulder)
Malignant
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Scalp
Common
- Trichilemmal cyst (syn. pilar cyst /no punctum)
Rare
- Sebaceous naevus (smooth pink-yellow patch / often present at birth / become warty with age /occasionally affects the face)
- Cylindroma (slow growing rubbery nodules)
Face
Relatively common
- Sebaceous gland hyperplasia (multiple / 1-3mm / white-yellow papules)
- Milium (multiple /small white papules)
- Xanthalasma (yellow papules, often elongated / single to several)
- Fibrous papule of the face (solitary / skin-coloured papule / nose most common site)
- Solitary circumscribed neuroma (solitary / firm skin-coloured papule / most commonly seen near muco-cutaneous junctions of face)
Rare
- Dermoid cyst (often present at birth / head and neck)
- Appendageal tumours (more common on the face but can affect almost any part of the body)
- Angiofibroma (multiple / skin-coloured papules / snout area / tuberous sclerosis)
- Naevus of Ota (asiatics / blue-grey patch / peri-orbital)
Ears
Lips
- Venous lake (blue, soft and compressible)
- Superficial mucocele (cyst)
- Fordyce spots (punctate yellow papules)
- Mucosal melanocytic macules (brown)
- Leukoplakia (white)
Limbs
Relatively common
Rare
- Pigmented spindle cell naevus of reed (a dense black macule or papule)
- Clear cell acanthoma (most common site is lower legs /firm nodule with scaly rim)
- Desmoplastic naevus (most common site is upper arms / similar appearance to a dermatofibroma)
- Rheumaoid nodule (firm subcutaneous nodules / ulnar border of forearm and knees)
- Leiomyoma (multiple painful lesions)
Hands
Common
- Ganglion (soft subcutaneous swelling / dorsal aspects of wrists most common site)
- Myxoid cyst (syn. mucous cyst / shiny tense papule in posterior nail fold / can ouze clear fluid / grooves can develop in nail plate)
- Pyogenic granuloma (red papule or nodule /eroded and bleeds easily)
- Acquired fibrous nodules (firm /digits and periungual)
- Gouty tophi (small nodules, with time a white paste-like material will drain)
Uncommon / rare
- Rheumaoid nodule (firm subcutaneous nodules / dorsal aspects of hands)
- Periungual fibroma (smooth fleshy lesions around nasil folds / tuberous sclerosis)
- Multicentric reticulhistiocytosis (yellow-brown papules along sides of fingers)
Feet
Common
- Talon noir (black patch caused by trauma / heel most common site)
- Ganglion (soft subcutaneous swelling / dorsal asepcts of feet and close to ankles)
- Stucco keratosis (mulitple / <1cm / white / mainly lower legs)
- Piezogenic pedal papules (muliple skin coloures papules around heels)
Rare
- Verrucous carcinoma (fungating mass on sole of foot
- Eccrine poroma (moist, pink, elevated lesion / sole of foot)
Nails
Refer to:
Diagnostic tables - General Dermatology - Diagnosis based on prominent site - Nails
Genitalia
Refer to:
Diagnostic tables - General Dermatology - Diagnosis based on prominent site - Genital, oral and other mucosal membranes
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