History

Fact Explanation
Linear epidermal nevus- appears as multiple small growths with uniform, round shape and arranged in a linear pattern. The lesion is hyperpigmented and homogenous in color. This refers to a localized excess cell growth, where the cells are similar to the regional tissue.[1] There is cutaneous mosaicism and the lesions follow Blaschko's lines.[1]
Sebaceous nevus is flat, yellow colored areas on scalp and neck. Commonly seen in children.
Congenital melanocytic nevi Those of the congenital variety are present from birth. Usually more than 1cm in diameter and there is black discoloration. With maturation, there will be hair growth and cerebriform surface. The cause is hereditary[7]. There are intradermal melanocytes, with infiltrations in to deeper structures.The lesions are close to skin appendages such as hair follicles and sweat glands.[2] There is an increased risk of malignant change (especially with increased surface area). [1][8]
Junctional melanocytic nevi These lesions usually appear in the childhood. They are macules with circular demarcation and hyperpigmentation. Commonest sites are palms,soles,mucous membranes and genital areas. Neural crest-derived melanocytes[7] migrate to the epidermis in the embryo. Due to apoptosis, cells reduce in number but the number remains high in areas close to the head, dorsum of extremities, and presacral area.[2] Junctional nevi result from proliferation of epidermal melanocytes at the junction of the epidermis and the dermis[3][4]
Compound melanocytic nevi- appear as a hyper pigmented nodule of 1cm of diameter with a domed shape. This is due to the migration of some melanocytes to the dermis from the epidermis while some cells proliferate at dermo-epidermal junction.[2],[3],[4] Can arise from a junctional nevus.[1]
Intradermal melanocytic nevi- appear as a nodule of 1cm of diameter with a domed shape.The lesions are less hyperpigmented and are close to skin color. When the epidermal melanocytes degenerate and dermal melanocytes persist, a intradermal nevus is formed [2],[4]
Splitz nevi- is a solitary pink nodule of roughly 1cm in diameter.It has a dome-shaped surface. This is common in children.The lesions appear in sites such as face or legs They have rapid growth.
Blue melanocytic nevi present as solitary lesions with blue color. Common in childhood.They are frequently seen on limbs,buttocks and back. Neural crest-derived melanocytes migrate to the epidermis in the embryo. Due to apoptosis, cells reduce in number but the number remains high in areas close to the head, dorsum of extremities, and presacral area.These areas are the common sites for blue nevi. In blue nevi,there are dermal collections of melanocytes. [2]
Atypical nevus syndrome causes lesions that are multiple and are greater than 5 mm in diameter.They have irregular borders, oval in shape, pink or brown in color. Common in sun-exposed areas such ( scalp, upper limbs and trunk). This is due to a autosomal dominant trait or a sporadic variant.[1] To diagnose, the individual should have more than 50 moles (melanocytic) and three or more should be atypical in their appearance
Features of suggestive of malignant change There is variable change in pigmentation and irregularity in shape.There will be a history of rapid enlargement, inflammation, ulceration and bleeding. [1],[6]There may be symptoms of distant metastasis. (Eg;-Bone pain,pathological fractures, morning headache and localizing features) [5]
Presence of risk factors Family history, sun exposure can increase the occurrence of nevi.[1]
References
  1. WELLER,Richard.et al.ed. Clinical dermatology.4th ed.Oxford:Blackwell publishing Ltd.2008.pp.293-298
  2. Nevi.Pathophysiology.BMJ best practice[online]BMJ Publishing Group2013[viewed 20 May 2014]Available form:http://bestpractice.bmj.com/best-practice/monograph/854/basics/pathophysiology.html
  3. Moles.DermNet NZ[online].DermNet New Zealand Trust.2013[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/moles.html
  4. BROWN,Robin Graham.BURNS,Tony.DERMATOLOGY Lecture Notes.10th ed.Sussex:WIELY-BLACKWELL.2011.PP.95-101
  5. Metastatic melanoma.DermNet NZ[online].DermNet New Zealand Trust.2014[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/metastatic-melanoma.html
  6. BISHOP JN, BATAILLE V, GAVIN A, LENS M, MARSDEN J, MATHEWS T, WHEELHOUSE C. The prevention, diagnosis, referral and management of melanoma of the skin: concise guidelines. Clin Med [online] 2007 Jun, 7(3):283-90 [viewed 22 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/17633952
  7. BAXTER LL, PAVAN WJ. The etiology and molecular genetics of human pigmentation disorders Wiley Interdiscip Rev Dev Biol [online] 2013 May, 2(3):379-392 [viewed 22 May 2014] Available from: doi:10.1002/wdev.72
  8. VIANA AC, GONTIJO B, BITTENCOURT FV. Giant congenital melanocytic nevus An Bras Dermatol [online] 2013, 88(6):863-878 [viewed 22 May 2014] Available from: doi:10.1590/abd1806-4841.20132233

Examination

Fact Explanation
Linear epidermal nevus There are multiple small growths with uniform, round shape and arranged in a linear pattern. The lesion is hyperpigmented and homogenous in color. There is cutaneous mosaicism and the lesions follow Blaschko's lines.[1] The use of Dermoscopy(examination by using skin surface microscopy) is helpful in diagnosis. The color and structure(SymmetryHomogeneity,pigmentation, keratinization, Vascular pattern, Border, ulcerations) is assessed.[7]
Sebaceous nevus Appear as flat, yellow colored areas on scalp and neck.
Congenital melanocytic nevi Usually more than 1cm in diameter and there is black discoloration.With maturation, there will be hair growth and cerebriform surface.
Junctional melanocytic nevi These are macules with circular demarcation and hyperpigmentation.Commonest sites are palms,soles,mucous membranes and genital areas.
Compound melanocytic nevi These are nodule of 1cm of diameter with a domed shape.The lesions are hyperpigmented.
Intradermal melanocytic nevi There are nodules of 1cm in diameter with a domed shape.The lesions are less hyperpigmented and possess skin color.
Splitz nevi Spitz naevus or epithelioid cell naevus, is a solitary pink nodule of roughly 1cm in diameter.It has a dome-shaped surface.
Blue nevi They present as solitary lesions with blue color. Frequently seen on limbs,buttocks and back.
Atypical nevus syndrome The lesions are multiple in number, and are greater than 5 mm in diameter.They have irregular borders, oval shape, and a pink or brown color. They are common in sun-exposed areas such ( scalp, upper limbs and trunk).
Signs of malignant change and distant metastasis. Variable change in pigmentation and irregularity in shape, a history of rapid enlargement,inflammation,ulceration and bleeding is suggestive of malignant change. [1],[6] Features to suggest distant metastasis are: 1.Satellite lesions, Local, distant lymph-node enlargement 2.Papiloedema and localizing signs(Focal weakness) that suggest cerebral metstasis. 3.Hepatomegaly and ascitis. 4.Lobar collapses, pleural effusions.
References
  1. WELLER,Richard.et al.ed. Clinical dermatology.4th ed.Oxford:Blackwell publishing Ltd.2008.pp.293-298
  2. Nevi.Pathophysiology.BMJ best practice[online]BMJ Publishing Group2013[viewed 20 May 2014]Available form:http://bestpractice.bmj.com/best-practice/monograph/854/basics/pathophysiology.html
  3. Moles.DermNet NZ[online].DermNet New Zealand Trust.2013[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/moles.html
  4. BROWN,Robin Graham.BURNS,Tony.DERMATOLOGY Lecture Notes.10th ed.Sussex:WIELY-BLACKWELL.2011.PP.95-101
  5. Metastatic melanoma.DermNet NZ[online].DermNet New Zealand Trust.2014[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/metastatic-melanoma.html
  6. BISHOP JN, BATAILLE V, GAVIN A, LENS M, MARSDEN J, MATHEWS T, WHEELHOUSE C. The prevention, diagnosis, referral and management of melanoma of the skin: concise guidelines. Clin Med [online] 2007 Jun, 7(3):283-90 [viewed 22 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/17633952
  7. Dermatoscopic features of pigmented lesions.DermNet NZ[online].DermNet New Zealand Trust.2013[viewed 22 May 2014].Available form:http://www.dermnetnz.org/procedures/dermoscopy.html

Differential Diagnoses

Fact Explanation
Malignant Melanoma There is irregularity in pigmentation color(more than one color in the same lesion) and irregularity in shape(asymmetry and the irregular borders). There will be a history of rapid enlargement and satellite lesions.There will be a itch probably due to inflammation.Commonly there will be ulceration and bleeding.[1],[2],[3]
Seborrhoeic ketatoses The lesions are flat, and hyperpigmented. Their surface can be either smooth or rough. The size is not larger than 3 cm in diameter.[2] There will be keratin plugs and horny cysts (seen with dermatoscopy).[1] With time,the lesions become more prominent. Usually there are multiple lesions on the chest and back.[2]
Lentigines There are hyperpigmented macules on skin and mucous membranes[1].They vary in size. Due to chronic sun exposure, and are observed on the sun-exposed skin of older people.[1][2]
Ephelides They are pale brown macules which are less than 3 mm in diameter.[2] Common in sun exposed areas.[1] Normal melanocytes get stimulated by UV light and produce melanin as a response.[2]
Haemangiomas Hemangiomas are vascular malformations. These can be misdiagnosed as vascular spitz nevus.[1] The lesions are flat, pink in color and found in the neonatal period. Commonly found on face and neck area.
References
  1. WELLER,Richard.et al.ed. Clinical dermatology.4th ed.Oxford:Blackwell publishing Ltd.2008.pp.293-298
  2. Melanoma and pigmented lesions.Clinical Knowledge summaries.NICE[online].National Institute for Health and care Excellence.2011.[viewed 20 May 2014].Available form:http://cks.nice.org.uk/melanoma-and-pigmented-lesions
  3. BISHOP JN, BATAILLE V, GAVIN A, LENS M, MARSDEN J, MATHEWS T, WHEELHOUSE C. The prevention, diagnosis, referral and management of melanoma of the skin: concise guidelines. Clin Med [online] 2007 Jun, 7(3):283-90 [viewed 22 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/17633952

Investigations - for Diagnosis

Fact Explanation
Excision biopsy and histological examination Nevi are diagnosed clinically by their typical appearance. Excision biopsy is indicated if a malignant melanoma is suspected. [1,2]
References
  1. Moles.DermNet NZ[online].DermNet New Zealand Trust.2013[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/moles.html
  2. Melanoma and pigmented lesions.Clinical Knowledge summaries.NICE[online].National Institute for Health and care Excellence.2011.[viewed 20 May 2014].Available form:http://cks.nice.org.uk/melanoma-and-pigmented-lesions

Investigations - Screening/Staging

Fact Explanation
Skin biopsy and a sentinel node biopsy This is to identify the characteristic histological features in a suspected malignant melanoma. [1]
Serum LDH levels This is a marker and a prognostic indicator for metastatic disease, in a malignant melanoma. [1][2]
Imaging for metastatic disease in malignant melanoma Chest X Ray, Ultrasound scan, CT, MRI and PET scan will provide evidence on metastatic disease. [1][2]
References
  1. Metastatic melanoma.DermNet NZ[online].DermNet New Zealand Trust.2014[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/metastatic-melanoma.html
  2. RASTRELLI M, TROPEA S, PIGOZZO J, BEZZON E, CAMPANA LG, STRAMARE R, ALAIBAC M, ROSSI CR. Melanoma m1: Diagnosis and Therapy. In Vivo [online] 2014 May-Jun, 28(3):273-85 [viewed 22 May 2014] Available from: http://www.ncbi.nlm.nih.gov/pubmed/24815827

Management - General Measures

Fact Explanation
Patient education If the lesion has minimal chance of malignant change,reassurance is important. Treatment is only indicated for cosmetic reasons. [1] Inform the patient about the features of malignant changes and the importance of medical referral in such a situation.[1] Educate the patient on regular self examination[2]
Education of patients with increased risk of malignant change Following patients have increased risk of developing a malignant melanoma: a large number of normal moles, five or more atypical moles, giant congenital melanocytic nevus. [1] Exposure to sun can give rise to melanoma so they are advised to avoid sunburn by following these steps: use clothing to cover, use a broad-spectrum sunscreen apply to cover the whole body, avoid tanning booths and sunbeds. [1,2]
References
  1. Melanoma and pigmented lesions.Clinical Knowledge summaries.NICE[online].National Institute for Health and care Excellence.2011.[viewed 20 May 2014].Available form:http://cks.nice.org.uk/melanoma-and-pigmented-lesions
  2. Moles.DermNet NZ[online].DermNet New Zealand Trust.2013[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/moles.html

Management - Specific Treatments

Fact Explanation
Removal of nevi with shave biopsy or excision biopsy There are several indication for the removal of nevi: a doubtful diagnosis, repeated trauma or inflammation, cosmetic reasons. [1] Shave biopsy can be done under local anesthesia. A scalpel or electrocautery can be used.[2] Excision biopsy is done for a flat nevus or when melanoma is suspected.[2] Laser treatment can be also considered in the method of removal of the nevus.[4]
Alternative treatment options Dermabrasion, laser therapy, chemical peels, and curettage[5] are considered in limited, patient specific situations.
Referral to higher levels of care Urgent referral to a specialist centre is needed if the lesion is suggestive of malignant melanoma.[3] Routinely referral for risk estimation and follow up should be done in high risk groups (giant congenital pigmented nevi, a family history of 3 or more diagnosed melanoma patients, more than 100 normal moles or the presence of atypical moles.) [3]
References
  1. WELLER,Richard.et al.ed. Clinical dermatology.4th ed.Oxford:Blackwell publishing Ltd.2008.pp.293-298
  2. Moles.DermNet NZ[online].DermNet New Zealand Trust.2013[viewed 20 May 2014].Available form:http://www.dermnetnz.org/lesions/moles.html
  3. Melanoma and pigmented lesions.Clinical Knowledge summaries.NICE[online].National Institute for Health and care Excellence.2011.[viewed 20 May 2014].Available form:http://cks.nice.org.uk/melanoma-and-pigmented-lesions
  4. LIM JY, JEONG Y, WHANG KK. A Combination of Dual-mode 2,940 nm Er:YAG Laser Ablation with Surgical Excision for Treating Medium-sized Congenital Melanocytic Nevus Ann Dermatol [online] 2009 May, 21(2):120-124 [viewed 22 May 2014] Available from: doi:10.5021/ad.2009.21.2.120
  5. SLUTSKY JB, BARR JM, FEMIA AN, MARGHOOB AA. Large congenital melanocytic nevi: associated risks and management considerations. Semin Cutan Med Surg [online] 2010 Jun, 29(2):79-84 [viewed 22 May 2014] Available from: doi:10.1016/j.sder.2010.04.007