Contents

Search

lentigo maligna melanoma

Least common of 3 principal melanomas of Caucasians. Etiology: 1) lentigo maligna melanoma evolves very slowly from lentigo maligna over a period of years (may take 20 years) 2) risk factors: a) age b) sun exposure (outdoor occupations, etc) c) HCTZ (RR=1.2) [3] Epidemiology: 1) median age is 65-70 2) equal incidence in males & females 3) rare in Asians, East Indians, blacks 4) 5-10% of primary cutaneous melanomas Clinical manifestations: 1) pigmented macules with variation in hues of brown & black plus gray areas indicating focal regression 2) areas of blue, black or pink papules & nodules 3) non pigmented lesions are rare 4) 3 mm to 2 cm or larger in size 5) distribution: a) single isolated lesion on sun-exposed surface b) especially malar region of cheek & temple 6) shape: irregular but sharply defined borders with inlets & peninsulas 7) other manifestations of sun-damaged skin a) telangiectasia b) marked freckling c) atrophy & solar keratosis d) basal cell carcinoma Differential diagnosis: 1) lentigo maligna 2) seborrheic keratosis 3) nodular melanoma; berry-like lesions that can arise from pre-existing nevi Management: 1) check for regional lymphadenopathy 2) surgical excision a) margin of at least 1.0 cm beyond clinically visible lesion b) use of Wood's lamp may help define borders c) excision down to or including the fascia d) skin graft will be necessary e) dissection of regional lymph node only if clinically palpable f) neoadjuvant topical imiquimod, 5%, cream prior to conservatively staged excision (see lentigo maligna)

Related

lentigo maligna seborrheic keratosis

General

cutaneous melanoma

References

  1. Color Atlas & Synopsis of Clinical Dermatology, Common & Serious Diseases, 3rd ed, Fitzpatrick et al, McGraw Hill, NY, 1997, pg 192-94
  2. Harrison's Principles of Internal Medicine, 14th ed. Fauci et al (eds), McGraw-Hill Inc. NY, 1998, pg 544
  3. Pottegard A, Pedersen SA, Schmidt SAJ et al Association of Hydrochlorothiazide Use and Risk of Malignant Melanoma. JAMA Intern Med. Published online May 29, 2018. PMID: 29813157 https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2682616