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Becker Melanosis
Introduction
Becker melanosis (Beckers nevus) is a form of acquired hyperpigmentation. S William Becker first described the condition in 1949, in 2 reported cases, as "concurrent melanosis and hypertrichosis in the distribution of nevus unius lateris."[1] See Image. Becker Melanosis.
Etiology
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Etiology
The exact etiology is not clear. Becker melanosis is considered a benign, late-onset type of epidermal nevus, and associated features like peri pubertal development, male preponderance, hypertrichosis, and acneiform lesions suggest a role for androgens. An increase in the number of androgen receptors has been reported.[2]
Epidemiology
Men are more commonly affected (male-to-female ratio of about 5:1). Becker melanosis has an estimated prevalence of 0.5% among men. The lesion usually presents during puberty, but rarely, cases of Becker melanosis presenting at birth or early childhood have been reported; familial occurrence of Becker melanosis has been reported. Some studies have shown a higher incidence among Black individuals.[3][4]
Pathophysiology
Androgen sensitivity and stimulation have been suggested as one of the main factors involved in the pathogenesis of Becker nevus. The onset of the lesions during adolescence, preponderance in men, and associated features like hypertrichosis and acneiform lesions have all been linked to the role of androgens in the pathophysiology. Results from some studies have reported an increased amount of androgen receptors in the lesional skin. Post-zygotic mutations in beta-actin have been reported in association with both Becker nevus and Becker nevus syndrome.[5][6]
History and Physical
Becker melanosis presents as a well-defined, unilateral, hyperpigmented tan or brown patch which increases in size, gradually often developing into a geographic pattern. Some studies have reported the right side of the body to be more commonly affected, with the most common sites involved being the shoulder, scapular area, and upper arms. Rarely, Becker melanosis may present with bilateral lesions on atypical sites like the lower limbs. Significant hair growth over the lesions is usually seen sometime after the hyperpigmentation is established and may take months to years to develop, and acneiform lesions may develop over the affected area.
Becker melanosis may be associated with other findings related to ectodermal abnormalities known as Becker nevus syndrome. Reported associations include smooth muscle hamartomas, hypoplasia of the breast, pectoral muscle and fat, limb hypertrophy, adrenal gland hyperplasia, and accessory scrotum; a rare association with melanoma has been reported. Once developed, the natural course is for the lesions to persist indefinitely. The hypertrichosis typically develops after the hyperpigmentation, and the hairs become progressively coarse with time. Some study results have suggested that hypertrichosis may not be associated with most of the cases of Becker melanosis.[3][7][3][8][9][10]
Evaluation
The diagnosis is mainly clinical. A skin biopsy shows mild acanthosis and hyperkeratosis. Increased melanin is seen in the basal layer, although the number of melanocytes tends to be normal. Dermal melanophages can be seen. Other histopathological features include elongation of the rete ridges, smooth muscle, and sebaceous gland hyperplasia. The hyperproliferation of keratinocytes, melanocytes, arrector pili muscle, and dermal nerve fibers have been reported in recent studies. Some immunohistochemical studies have shown increased expression of some markers like epidermal Ki-67, melan-A, and keratin 15 in the lesional and perilesional skin compared to normal skin. Dermal nerve fiber length and expression of smooth muscle actin have also been reported to be higher in the lesional skin of Becker melanosis.[11][10][12]
Treatment / Management
The hyperpigmentation of Becker melanosis usually remains stable, although there are reports of the pigmentation fading spontaneously in some cases. Treatment is mainly indicated for cosmetic reasons, especially the rapid transformation of the lesion during adolescence. The hyperpigmentation and the hypertrichosis respond to lasers. Different types of lasers have been found to be effective in Becker melanosis, like the Q-switched Ruby laser, Q-switched Nd YAG, long-pulsed Alexandrite, and various fractional ablative lasers. The most commonly used lasers are the Q-switched ruby and the Q-switched Nd YAG lasers. However, both are associated with a high rate of recurrence. Hypertrichotic lesions have been reported to respond to combinations of fractional lasers (like the 1550 nm non-ablative laser) with hair removal lasers. Multiple sessions are required for optimum results.
Electrolysis has also been reported to effectively treat the hypertrichosis associated with Becker melanosis. Sun protection is advised, as sun exposure might make the lesions appear darker. Acneiform lesions have been found to respond to topical retinoids. In patients with associated breast hypoplasia, a novel yet effective treatment is breast lipofilling (eg, fat grafting to treat the cosmetic defect related to ipsilateral breast hypoplasia), which can be associated with Becker melanosis. Cosmetic camouflage can be useful in addressing the psychosocial issues and quality of life in patients who have lesions in relatively exposed areas.[13][14][15](B3)
Differential Diagnosis
The differential diagnoses for Becker melanosis include the following:
- Albright syndrome
- Congenital melanocytic nevus
- Congenital smooth muscle hamartoma
- Overdevelopment of a tissue such as the adrenal gland, limb, fingers, or toes
- Post-inflammatory hyperpigmentation
- Smooth muscle hamartoma
- Under the development of underlying structures such as breast, fat, or limb
Pearls and Other Issues
Although the typical presentation is a single, unilateral, hyperpigmented, or tan-colored macule over the shoulder or pectoral area, Becker melanosis has been reported to manifest in various atypical presentations. Associated abnormalities include unilateral hypoplasia of the breast, which can vary in magnitude, affecting the whole breast area or the nipple/areola alone. Supernumerary nipples can also occur as an association with aplasia of the ipsilateral pectoralis major muscle, ipsilateral limb shortening, localized lipoatrophy, spina bifida, scoliosis, pectus carinatum, quadriparesis, osteoma cutis, congenital adrenal hyperplasia, and accessory scrotum.
Becker melanosis has been found to occur in association with phakomatosis pigmentovascularis and neurofibromatosis. Becker melanosis associated with nevus depigmentosus has been described as a possible example of twin spotting. A case report has mentioned the occurrence of basal cell carcinoma occurring on the site of Becker melanosis in a sun-protected area. Hypohidrosis associated with Becker melanosis has been reported, and pityriasis versicolor localized to the area of Becker melanosis has been described.
Multiple and bilateral lesions have rarely been reported. A case of giant, bilateral Becker melanosis simulating the armor of a gladiator's arm has been described. The same patient also had marginal osteophytes over the cervical vertebrae. Becker melanosis is associated with short stature, skeletal deformities, and mental retardation. Bilateral, congenital Becker melanosis has been described. Becker melanosis occurs in siblings. Atypical sites of involvement include the lower limbs. Many cases may present with a later onset and absence of hypertrichosis.[8][16][17][18][19]
Enhancing Healthcare Team Outcomes
Looking for extracutaneous involvement in all cases of suspected Beckers melanosis is important. Patients must know the possibility of increased hair growth over the lesions and that the treatment is for cosmetic purposes only. Advanced surgical treatment requires a coordinated effort from dermatologists and plastic surgeons; lasers are 1 of the main evidence-based management options for better cosmesis in Beckers melanosis.[15]
Media
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Becker Melanosis. Becker melanosis (Becker nevus) is a form of acquired hyperpigmentation.
References
BECKER SW. Concurrent melanosis and hypertrichosis in distribution of nevus unius lateris. Archives of dermatology and syphilology. 1949 Aug:60(2):155-60 [PubMed PMID: 18133444]
Patel P, Malik K, Khachemoune A. Sebaceus and Becker's Nevus: Overview of Their Presentation, Pathogenesis, Associations, and Treatment. American journal of clinical dermatology. 2015 Jun:16(3):197-204. doi: 10.1007/s40257-015-0123-y. Epub [PubMed PMID: 25782676]
Level 3 (low-level) evidencePatrizi A, Medri M, Raone B, Bianchi F, Aprile S, Neri I. Clinical characteristics of Becker's nevus in children: report of 118 cases from Italy. Pediatric dermatology. 2012 Sep-Oct:29(5):571-4. doi: 10.1111/j.1525-1470.2012.01734.x. Epub 2012 Apr 4 [PubMed PMID: 22471889]
Level 2 (mid-level) evidenceDanarti R, König A, Salhi A, Bittar M, Happle R. Becker's nevus syndrome revisited. Journal of the American Academy of Dermatology. 2004 Dec:51(6):965-9 [PubMed PMID: 15583590]
Kim YJ, Han JH, Kang HY, Lee ES, Kim YC. Androgen receptor overexpression in Becker nevus: histopathologic and immunohistochemical analysis. Journal of cutaneous pathology. 2008 Dec:35(12):1121-6. doi: 10.1111/j.1600-0560.2008.00988.x. Epub [PubMed PMID: 18616760]
Cai ED, Sun BK, Chiang A, Rogers A, Bernet L, Cheng B, Teng J, Rieger KE, Sarin KY. Postzygotic Mutations in Beta-Actin Are Associated with Becker's Nevus and Becker's Nevus Syndrome. The Journal of investigative dermatology. 2017 Aug:137(8):1795-1798. doi: 10.1016/j.jid.2017.03.017. Epub 2017 Mar 24 [PubMed PMID: 28347698]
Sheng P, Cheng YL, Cai CC, Guo WJ, Zhou Y, Shi G, Fan YM. Clinicopathological Features and Immunohistochemical Alterations of Keratinocyte Proliferation, Melanocyte Density, Smooth Muscle Hyperplasia and Nerve Fiber Distribution in Becker's Nevus. Annals of dermatology. 2016 Dec:28(6):697-703 [PubMed PMID: 27904268]
Dasegowda SB, Basavaraj G, Nischal K, Swaroop M, Umashankar N, Swamy SS. Becker's Nevus Syndrome. Indian journal of dermatology. 2014 Jul:59(4):421. doi: 10.4103/0019-5154.135530. Epub [PubMed PMID: 25071279]
Manoj J, Kaliyadan F, Hiran KR. Atypical presentation of Becker's melanosis. Indian dermatology online journal. 2011 Jan:2(1):42-3. doi: 10.4103/2229-5178.79856. Epub [PubMed PMID: 23130219]
AlGhamdi KM, AlKhalifah AI, AlSheikh AM, AlSaif FM. Clinicopathologic profile of Becker's melanosis with atypical features. Journal of drugs in dermatology : JDD. 2009 Aug:8(8):745-8 [PubMed PMID: 19663112]
Level 2 (mid-level) evidenceBhawan J, Chang WH. Becker's melanosis: an ultrastructural study. Dermatologica. 1979:159(3):221-30 [PubMed PMID: 478060]
Level 3 (low-level) evidenceBoiron G, Surlève-Bazeille JE, Maleville J. [Becker's melanosis. Study of seven cases by photonic and electron microscopy. Contribution to the histogenesis of the cytoid bodies (author's transl)]. Annales de dermatologie et de venereologie. 1980 Aug-Sep:107(8-9):787-97 [PubMed PMID: 7447258]
Level 3 (low-level) evidenceKansal NK. Lightening Becker nevus: Role of topical therapies. Journal of the American Academy of Dermatology. 2019 Feb:80(2):e39. doi: 10.1016/j.jaad.2018.08.038. Epub 2018 Sep 6 [PubMed PMID: 30195570]
Al-Saif F, Al-Mekhadab E, Al-Saif H. Efficacy and safety of short-pulse erbium: Yttrium aluminum garnet laser treatment of Becker's nevus in Saudi patients: A pilot study. International journal of health sciences. 2017 Jul-Sep:11(3):14-17 [PubMed PMID: 28936145]
Level 3 (low-level) evidenceMomen S, Mallipeddi R, Al-Niaimi F. The use of lasers in Becker's naevus: An evidence-based review. Journal of cosmetic and laser therapy : official publication of the European Society for Laser Dermatology. 2016 Aug:18(4):188-92. doi: 10.3109/14764172.2015.1114647. Epub 2016 Mar 11 [PubMed PMID: 26735085]
Bisht YS, Bhasin R, Manoj S, Sunita BS, Singhal E. Becker's nevus syndrome. Medical journal, Armed Forces India. 2015 Jul:71(Suppl 1):S89-91. doi: 10.1016/j.mjafi.2013.04.010. Epub 2013 Aug 30 [PubMed PMID: 26265883]
Cohen PR. Poland's Syndrome: Are Postzygotic Mutations in β-Actin Associated with its Pathogenesis? American journal of clinical dermatology. 2018 Feb:19(1):133-134. doi: 10.1007/s40257-017-0330-9. Epub [PubMed PMID: 29139054]
Ghosh SK, Majumder B, Agarwal M. Becker's nevus syndrome: a report of a rare disease with unusual associations. International journal of dermatology. 2017 Apr:56(4):458-460. doi: 10.1111/ijd.13378. Epub 2016 Sep 22 [PubMed PMID: 27655000]
Glinick SE, Alper JC, Bogaars H, Brown JA. Becker's melanosis: associated abnormalities. Journal of the American Academy of Dermatology. 1983 Oct:9(4):509-14 [PubMed PMID: 6355214]
Level 3 (low-level) evidence