Acral lentiginous melanoma

Acral lentiginous melanoma
SpecialtyOncology, dermatology Edit this on Wikidata
SymptomsAreas of dark pigmentation [1]
CausesMalignant melanocytes[2][3]
Diagnostic methodBiopsy[4]
TreatmentBiologic immunotherapy agents[5]
FrequencyMales = Females[6]

Acral lentiginous melanoma is a type of skin cancer.[6] It typically begins as a uniform brownish mark before becoming darker and wider with a blurred irregular edge, most frequently seen in the foot of a person with darker skin.[6] It may become bumpy and ulcerate.[6] Just under the nail it typically appears as dark longitudinal streaks, and it may spread.[7]

Melanoma is a group of serious skin cancers that arise from pigment cells (melanocytes); acral lentiginous melanoma is a kind of lentiginous[8] skin melanoma.[6] Acral lentiginous melanoma is the most common subtype in people with darker skins and is rare in people with lighter skin types.[7] It is not caused by exposure to sunlight or UV radiation, and wearing sunscreen does not protect against it. Acral lentiginous melanoma is commonly found on the palms, soles, under the nails, and in the oral mucosa. It occurs on non-hair-bearing surfaces of the body, which have not necessarily been exposed to sunlight. It is also found on mucous membranes.[9]

The absolute incidence of ALM is the same for people of all skin colors, and has not changed significantly for decades.[9] However, because rates of other melanomas are low in non-white populations, ALM is the most common form of melanoma diagnosed amongst Asian and sub-Saharan African ethnic groups.[10] The average age at diagnosis is between sixty and seventy years.[11]

Males and females are affected equally.[6]

Signs and symptoms

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Typical signs of acral lentiginous melanoma include the following [1]

Warning signs are new areas of pigmentation, or existing pigmentation that shows change. If caught early, acral lentiginous melanoma has a similar cure rate as the other types of superficial spreading melanoma.[12]

Causes

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Acral lentiginous melanoma is a result of malignant melanocytes at the membrane of the skin (outer layers).[2][3] The pathogenesis of acral lentiginous melanoma remains unknown at this time.[13] It is not caused by sunlight or UV radiation.[9]

Diagnosis

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Although the ideal method of diagnosis of melanoma is complete excisional biopsy,[14] alternatives may be required according to the location of the melanoma. Dermatoscopy of acral pigmented lesions is very difficult but can be accomplished with diligent focus. Initial confirmation of the suspicion can be done with a small wedge biopsy or small punch biopsy.[4] Thin deep wedge biopsies can heal very well on acral skin, and small punch biopsies can give enough clue to the malignant nature of the lesion. Once this confirmatory biopsy is done, a second complete excisional skin biopsy can be performed with a narrow surgical margin (1 mm). This second biopsy will determine the depth and invasiveness of the melanoma,[15] and will help to define what the final treatment will be. If the melanoma involves the nail fold and the nail bed, complete excision of the nail unit might be required. Final treatment might require wider excision (margins of 0.5 cm or more), digital amputation, lymphangiogram with lymph node dissection, or chemotherapy.[16]

Histology

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Acral lentiginous melanoma (ALM)

The main characteristic of acral lentiginous melanoma is continuous proliferation of atypical melanocytes at the dermoepidermal junction.[17] Other histological signs of acral lentiginous melanoma include dermal invasion and desmoplasia.[18]

According to Scolyer et al.,[19] ALM "is usually characterized in its earliest recognisable form as single atypical melanocytes scattered along the junctional epidermal layer".

Treatment

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Therapies for metastatic melanoma include the biologic immunotherapy agents ipilimumab, pembrolizumab, and nivolumab; BRAF inhibitors, such as vemurafenib and dabrafenib; and a MEK inhibitor trametinib.[5]

When arising in the nailbed of a digit, the evidence suggests that digit-sparing surgery (wide excision and grafting) has similar outcomes to amputation,[20] therefore, to preserve function it is recommended that clinicians default to digit-sparing surgery and if the margins are involved or patients develop recurrence, then secondary amputation can be considered.

Prognosis

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It has been demonstrated that acral lentiginous melanoma has a poorer prognosis compared to that of cutaneous malignant melanoma (CMM).[21]

Society and culture

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Jamaican musician Bob Marley died of the condition in 1981, at the age of 36.[22]

See also

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References

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  1. ^ a b Goodheart HP (2010-10-25). Goodheart's Same-site Differential Diagnosis: A Rapid Method of Diagnosing and Treating Common Skin Disorders. Lippincott Williams & Wilkins. ISBN 978-1-60547-746-6.
  2. ^ a b Brown KM, Chao C (2014). Melanoma. Elsevier Health Sciences. ISBN 978-0-323-32683-4. Archived from the original on 2023-01-11. Retrieved 2020-12-06.
  3. ^ a b Piliang MP (June 2011). "Acral Lentiginous Melanoma". Clinics in Laboratory Medicine. 31 (2): 281–288. doi:10.1016/j.cll.2011.03.005. PMID 21549241. </
  4. ^ a b ChB DE, PhD SJ (2014-11-10). Superficial Melanocytic Pathology. Demos Medical Publishing. ISBN 978-1-62070-023-5. Archived from the original on 2023-01-11. Retrieved 2020-12-06.
  5. ^ a b Maverakis E, Cornelius L, Bowen G, Phan T, Patel F, Fitzmaurice S, He Y, Burrall B, Duong C, Kloxin A, Sultani H, Wilken R, Martinez S, Patel F (2015). "Metastatic Melanoma – A Review of Current and Future Treatment Options". Acta Dermato Venereologica. 95 (5): 516–524. doi:10.2340/00015555-2035. PMID 25520039.
  6. ^ a b c d e f James WD, Elston D, Treat JR, Rosenbach MA, Neuhaus I (2020). "30. Melanocytic nevi and neoplasms". Andrews' Diseases of the Skin: Clinical Dermatology (13th ed.). Edinburgh: Elsevier. pp. 696–697. ISBN 978-0-323-54753-6.
  7. ^ a b Hall KH, Rapini RP (2024). "Acral Lentiginous Melanoma". StatPearls. StatPearls Publishing. PMID 32644539.
  8. ^ Phan A, Touzet S, Dalle S, Ronger-Savlé S, Balme B, Thomas L (August 2007). "Acral lentiginous melanoma: histopathological prognostic features of 121 cases". British Journal of Dermatology. 157 (2): 311–318. doi:10.1111/j.1365-2133.2007.08031.x. PMID 17596173. S2CID 40412082.
  9. ^ a b c LeBoit PE (2006). Pathology and Genetics of Skin Tumours. IARC. ISBN 978-92-832-2414-3.
  10. ^ Farage MA (2010-01-22). Textbook of Aging Skin. Springer Science & Business Media. ISBN 978-3-540-89655-5. Archived from the original on 2023-01-11. Retrieved 2020-12-06.
  11. ^ Swartz MH (2014-01-07). Textbook of Physical Diagnosis: History and Examination. Elsevier Health Sciences. ISBN 978-0-323-22507-6. Archived from the original on 2023-01-11. Retrieved 2020-12-06.
  12. ^ Hearing VJ, Leong SP (2007-11-05). From Melanocytes to Melanoma: The Progression to Malignancy. Springer Science & Business Media. ISBN 978-1-59259-994-3.
  13. ^ David E. Elder, Sook Jung Yun (2014-11-10). Superficial Melanocytic Pathology. Demos Medical Publishing. p. 119. ISBN 978-1-61705-186-9. Retrieved 11 October 2016.
  14. ^ Shea CR, Reed JA, Prieto VG (2014-11-03). Pathology of Challenging Melanocytic Neoplasms: Diagnosis and Management. Springer. ISBN 978-1-4939-1444-9. Archived from the original on 2023-01-11. Retrieved 2020-12-06.
  15. ^ Barnhill RL, Piepkorn MW, Busam KJ, eds. (2014). Pathology of Melanocytic Nevi and Melanoma. doi:10.1007/978-3-642-38385-4. ISBN 978-3-642-38384-7.[page needed]
  16. ^ Clarke LE, Clarke JT, Helm KF (2014-03-01). Color Atlas of Differential Diagnosis in Dermatopathology. JP Medical Ltd. ISBN 978-93-5090-845-7. Archived from the original on 2023-01-11. Retrieved 2020-12-06.
  17. ^ Piliang MP (September 2009). "Acral Lentiginous Melanoma". Surgical Pathology Clinics. 2 (3): 535–541. doi:10.1016/j.path.2009.08.005. PMID 26838538.
  18. ^ Mooi W, Krausz T (2007-09-28). Pathology of Melanocytic Disorders 2ed. CRC Press. ISBN 978-1-4441-1380-8. Archived from the original on 2023-01-11. Retrieved 2020-12-06.
  19. ^ Scolyer RA, Long GV, Thompson JF (April 2011). "Evolving concepts in melanoma classification and their relevance to multidisciplinary melanoma patient care". Molecular Oncology. 5 (2): 124–136. doi:10.1016/j.molonc.2011.03.002. PMC 5528281. PMID 21482206.
  20. ^ Hardie CM, Wade RG, Wormald JC, Stafford B, Elliott F, Newton-Bishop J, Dewar D (October 2023). "Surgical excision methods for skin cancer involving the nail unit: A systematic review". Cochrane Evidence Synthesis and Methods. 1 (8). doi:10.1002/cesm.12026.
  21. ^ Bradford PT, Goldstein AM, McMaster ML, Tucker MA (April 2009). "Acral Lentiginous Melanoma: Incidence and Survival Patterns in the United States, 1986-2005". Archives of Dermatology. 145 (4): 427–434. doi:10.1001/archdermatol.2008.609. PMC 2735055. PMID 19380664.
  22. ^ "Bob Marley Shouldn't Have Died from Melanoma". Skin Cancer Foundation. 2016-02-06. Archived from the original on 2019-07-27. Retrieved 2016-10-11.

Further reading

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  • Durbec F, Martin L, Derancourt C, Grange F (April 2012). "Melanoma of the hand and foot: epidemiological, prognostic and genetic features. A systematic review: Melanoma of the hand and foot". British Journal of Dermatology. 166 (4): 727–739. doi:10.1111/j.1365-2133.2011.10772.x. PMID 22175696. S2CID 5463667.
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