Virendra N. Sehgal, MD; Prashant Verma, MD; Kingsukh Chatterjee, DNB
Dr. Sehgal is from the Dermato-Venereology Centre, Sehgal Nursing Home, Panchwati, Delhi, India. Dr. Verma is from the Department of Dermatology and Sexually Transmitted Diseases, Vardhman Mahavir Medical College & Safdarjang Hospital, Delhi. Dr. Chatterjee is from the Department of Dermatology, Bankura Sammilani Medical College, West Bengal, India.
The authors report no conflict of interest.
Correspondence: Virendra N. Seghal, MD, Dermato-Venerology Centre, Seghal Nursing Home, A/6 Panchwati, Delhi 220 033, India (drseghal@ndf.vsnl.net.in).
Freckling of the skin folds is the most common of the cardinal criteria for NF1. Other sites include under the neck and breasts, around the lips, and trunk. Their size ranges from 1 to 3 mm, distinguishing them from CALMs. Considered nearly pathognomonic, NF1 generally occurs in children aged 3 to 5 years in the axillae or groin.15,24
Cutaneous neurofibromas generally are cutaneous/dermal tumors that are dome shaped, soft, fleshy, and flesh colored to slightly hyperpigmented. Subcutaneous tumors are firm and nodular. Neurofibromas usually do not become apparent until puberty and may continue to increase in size and number throughout adulthood. Pregnancy also is associated with increased tumor growth.25 The tumors are comprised of Schwann cells, fibroblasts, mast cells, and perineural cells. There also is an admixture of collagen and extracellular matrix.26 The cutaneous and extracutaneous manifestations of NF1 are outlined in Table 1 and Table 2.27-31
Management
Type 1 neurofibromatosis needs to be differentiated from other conditions based on careful clinical examination. Additionally, histopathologic examination of the lesions, imaging studies (eg, MRI), echocardiography, regular skeletal roentgenogram, and detailed ophthalmologic examination are important to look for any visceral involvement. Painful and bleeding tumors and cosmetic enhancement warrant surgical intervention, including various surgical techniques and lasers.32,33 Application of sunscreen may make pigmentary alterations less noticeable over time. Although not often located on the face, CALMs also may be amenable to various makeup products. Various studies have demonstrated improvement of freckling and CALMs with topical vitamin D3 analogues and lovastatin (β-hydroxy-β-methylglutaryl-CoA reductase inhibitors)34-36; however, this needs further exploration. Rapamycin has demonstrated efficacy in reducing tumor volume in animal studies by inhibiting the mammalian target of rapamycin cellular pathway.37 Imatinib mesylate has demonstrated efficacy both in vivo and in vitro in mouse models by targeting the platelet-derived growth-factor receptors α and β.38
