top of page

M

Macrocystic lymphangioma 

Description: cysts more than 2 cm 

Mal de Meleda

Appearance: glove + stocking malodorous keratoderma, more erythematous

Inheritance: AR

Male Pattern Hair Loss

Etiology: increased sensitivity of androgen receptors in hair follicles to DHT

Location: frontal hairline, crown

Tx: topical minoxidil, oral finasteride or dutasteride

Marjolin Ulcer

Etiology: rare development of cutaneous SCC in the site of a scar or ulcer; most commonly forms at the site of an old thermal burn scar

Description: non-healing sore that steadily increases in size, has excessive granulation tissue, foul-smelling pus, and bleed easily on contact

Mastocytosis

Etiology: Gain of function mutation in KIT gene = growth of mast cells = more histamine release

Description: small reddish-brown spots or bumps (urticaria pigmentosa)

​Darier sign

maculopapular cutaneous mastocytosis

Two poorly demarcated hyperpigmented papules on the left upper chest with a single papule on the right clavicular region.

A well-demarcated hyperpigmented curvilinear plaque on the left distal forearm.

A solitary mastocytoma on an infant's chest

Juvenile mastocytosis: red-brown macular lesions on the trunk. They are likely to resolve over the next few years

Red-brown monomorphic maculopapules in adult-onset urticaria pigmentosa

A positive Darier sign - rubbing an area of mastocytosis has resulted in redness, swelling, and urtication in 5 minutes

Yellow-brown pigmented macules in juvenile mastocytosis

Juvenile mastocytosis: red-brown macular lesions on the neck. They are likely to resolve over the next few years

Mastocytosis in a baby - red-brown patches are characteristic. The left lower back lesion has urticated after rubbing - a positive Darier sign

Melanoma

Etiology: BRAF, NRAS, c-KIT, GNAQ, GNA11, CDKN2A, MC1R mutations; UV light exposure

Appearance: irregularly pigmented, asymmetrical macules or papules (ABCDE)

Types:

  • superficial spreading

  • nodular

  • lentigo maligna

  • acral lentiginous

Dermoscopy: blue/white veil, dark globules, peripheral globules, negative pigment network, pseudopods, radial streaming

Tx: wide local excision

Screening post dx:

  1. q3 mo for 1st yr

  2. q6 mo <5 yrs

  3. q1 yr >5 yrs​​

Small, but irregular, blue and black pigmented lesion

Irregular border, asymmetrical lesion on dark skin

Classic blue-black color.

Melanoma of the nail (discoloration of nailbed)

Round, bleeding melanoma that has a small "satellite" tumor underneath it.

Acral lentiginous malignant melanoma - irregular edge, with variable pigmentation, asymmetry and areas of regression on the heel

Nodular malignant melanoma in a vertical growth phase - rapidly enlarging scaly pigmented nodule

Amelanotic melanoma arising within pigmented melanoma

Irregular pigmented longitudinal bands in melanoma of the nail unit

Multiple blue nodules of cutaneous metastatic malignant melanoma

Amelanotic subungal melanoma - a red lesion arising from the nail fold that has produced destruction of the nail plate

Superficial spreading malignant melanoma - irregular border, variable pigmentation, and areas of clinical regression

A superficial malignant melanoma - irregular and notched margin, variable and irregular pigmentation in an itchy and enlarging pigmented lesion

Merkel Cell Carcinoma

Etiology: ultraviolet light exposure

Description: pearly pimple-like lump, sometimes skin-colored, red, purple or bluish-red, though they are rarely tender to the touch

At risk: older, fair skin, male gender, immunosuppressed

Milaria Rubra / Heat Rash

Appearance: small, erythematous blister-like papules

Etiology: sweat ducts become blocked, trapping sweat under skin, leading to inflammation

At risk: hot, humid environments

Location: skin folds, neck, chest, back

Milia

Appearance: 1-2 mm white to yellow subepidermal papules

Location: cheeks, eyelids, forehead, genitalia

Tx: nick surface + express; tretinoin

Cause: small cyst containing keratin

​Description: tiny pearly-white bumps just under the surface of the skin

​Locations: face, especially eyelids + cheeks

single milium

common on cheeks

Eruptive milia

Milia en plaque

Childhood milia

Milia en plaque

Following injury

Following bullous pemphigoid

Following bullous pemphigoid

Neonatal milia

Molluscum contagiosum

Etiology: poxvirus

Appearance: flesh colored dome-shaped papules +/- umbilication

Location: anywhere, but palms + soles are typically spared

Transmission: skin to skin + skin to fomite

Tx: self limited or if tx is wanted (cryo, cantharidin, podophyllotoxin cream)

BOTE sign = "Beginning Of The End" = indicates lesion is resolving due to the body's immune response; characterized by redness, tenderness + crusting

Mpox / Monkeypox

Etiology: Orthopoxvirus

Description: 

1. first 5 days of the infection, patients experience 'flu-like' symptoms

2. rash similar to that seen in chickenpox develops

3. maculopapules,evolve into vesicles, pseudpustules, crusting over, andn atrophic scars and lasts for around 10 days

Location: Lesions predominate on the face but may develop on the palms, soles, and dorsal hands and feet

At risk: MSM, endemic to Africa

Mycosis Fungoides

Etiology: unknown; triggers proliferation of cerebriform T cells 

Description: 

  • Patch stage = flat erythematous scaling with well-defined borders in non-sun-exposed areas or hypopigmented lesions on darker skinned individuals

  • Plaque stage = pruritic raised borders with irregular contours and reddish-brown in color

  • Tumor stage = exophytic violaceous lesion

Patch stage MY PUBLICATION :)

Plaque stage

Patch stage

Patch stage

Patch stage

Plaque stage

Plaque stage

Plaque stage

Patch & Plaque stage

Tumour stage

Tumour stage

Tumour stage

Myofibroma

Histo: hypocellular pink blue nodules with dilated branching staghorn vessels and cellular areas 

At risk: babies/kids

Types:

  • Single – MC, skin/SQ nodule

  • Muliptle

  • Generalized

bottom of page