Features Of Congenital Melanocytic Nevi Research Articles

New recommendations for the categorization of cutaneous features of congenital melanocytic nevi

The diameter of congenital melanocytic nevi (CMN) has served as the lone criterion for determining risks of adverse outcomes such as melanoma. A standardized description of additional morphologic features is needed. We sought to develop a consensus-based standardized categorization of cutaneous features of CMN and to test agreement among experts on the proposed scheme. An interdisciplinary group of experts in the field of CMN was surveyed using a detailed questionnaire. Applicability of the expert consensus-based scheme was tested for interobserver agreement. The principal variable of the consensus-based categorization is CMN size, based on maximal diameter the CMN is projected to attain by adulthood. CMN size categories include: small (<1.5 cm); medium (M1: 1.5-10 cm, M2: >10-20 cm); large (L1: >20-30 cm, L2: >30-40 cm); and giant (G1: >40-60 cm, G2: >60 cm). In addition, number of satellite nevi in the first year of life is categorized into none, 1 to 20, more than 20 to 50, and more than 50 satellites. Additional descriptors of CMN include anatomic localization, color heterogeneity, surface rugousity and presence of hypertrichosis (described as none, moderate, marked), and presence of dermal or subcutaneous nodules (none, scattered, extensive). Assessment of consistency among 3 experts showed moderate to excellent interobserver agreement for categorization of the clinical descriptors (kappa values 0.54-0.93). Applicability of the proposed scheme was tested in a virtual setting and only among experts. The proposed categorization scheme for CMN was agreed upon by experts and showed good interobserver agreement. Such standardized reporting of patients with CMN facilitates the development of an international clinical database for the study of large and giant CMN.

Prevalence and Clinical Features of Congenital Melanocytic Nevi in 1,000 Spanish Newborns

Background Congenital melanocytic nevus is a benign proliferation of melanocytes that is present at birth or develops in the first months of life. Although such lesions are common, few studies have analyzed their prevalence in Spain. Objectives The aim of this study was to define the prevalence and most frequent anatomical areas affected by congenital melanocytic nevi in our health service area. We also analyzed the influence of maternal and neonatal factors in the development of these lesions. Patients and methods We performed a prospective study of 1000 consecutive neonates seen in the first 72hours of life in the perinatology clinic of the Pediatrics Department of Hospital Arquitecto Marcide in Ferrol, Spain, recording specific maternal and neonatal variables and the size and site of congenital melanocytic nevi if present. Results Fourteen infants (10 girls and 4 boys; 12 white European, 2 North African; 1.4% of the study population) presented at least 1 melanocytic nevus. None had more than 1 lesion. Eight of the nevi were located on the trunk, 2 on the face, 2 on the upper limbs, and 2 on the lower limbs. The diameter of the lesions was less than 1.5cm in half of cases and between 1.5 and 3.5cm in the remainder. Conclusions There was a higher prevalence of congenital melanocytic nevi in preterm infants, females, and nonwhite infants. Maternal age, number of previous pregnancies, and birth weight do not appear to influence the prevalence of these lesions.

Clinical and dermoscopic features of congenital melanocytic nevi

Congenital melanocytic nevi (CMN) are nevomelanocytic nevi which are present at birth. In this study, we set out to determine the clinical and dermoscopic properties of CMN. A total of 239 lesions were diagnosed as CMN. Dermoscopic properties were noted. Age, sex, nevus location and nevus size of the patients were also collected from the patient records. A total of 239 lesions were diagnosed as CMN in 239 patients (age ranged from 1 month to 63 years (20.79 ± 13.76 yr); 114 [47.7%] males and 125 [52.3%] females). Most of the lesions were medium-sized CMN, followed by small and large ones. The most common localization was upper extremities (23.8%), followed by head and neck, back, and lower extremities respectively. Dark brown was the most common colour seen in dermoscopy (115 patients, 48.1%), followed by light brown (69 patients, 28.9%) and black (55 patients, 23%) respectively. The most common dermoscopic findings of CMN was hair follicles followed by dots (70%) and perifollicular hypopigmentation (51%). Our study describes the normal clinical and dermoscopic features of CMN. It should be kept in mind that, CMNs are quite common lesions, and melanomas can arise from them. Knowing and being familiar with the normal properties of these common nevi will help us determine whether a nevus is suspicious or not.

Reproducibility of Dermoscopic Features of Congenital Melanocytic Nevi

Background: The dermoscopic features of congenital melanocytic nevi (CMN) have recently been described, and some structures have been proposed as distinctive of these moles. Objective: The aim of our study was to evaluate the agreement between observers, i.e. the reproducibility, in the identification of these features. Method: Fifty-two CMN, randomly selected from 127 male subjects carrying at least 1 CMN, were examined by a 1st medium-experienced observer. The image recording was performed according to the dermoscopic patterns of the Consensus Net Meeting on Dermoscopy and to the features proposed for CMN by Seidenari et al. The presence/absence of these features was recorded in a specifically developed patient’s card, and the most typical dermoscopic features of the lesions were also photographed and observed again in this form by the same investigator and by a 2nd basic-experienced observer. The reproducibility of the dermoscopic features assessed directly and on photographs by the 1st observer (intraobserver agreement) and the agreement between the 1st and the 2nd observers judging nevi on photographs (interobserver agreement) were estimated by Cohen’s kappa statistics. Results: Intraobserver agreement was highly satisfactory for all the dermoscopic features, with the exception of focal thickening of network lines and follicles (satisfactory), and hyperpigmented areas and target vessels (fairly satisfactory), which were more frequently identified on Dermaphot pictures. Interobserver agreementwas highly satisfactory for network, globules/dots, blotches, focal hypopigmentation, skin furrow hypopigmentation and follicles; it was satisfactoryfor perifollicular hypopigmentation, vessels and target vessels, and barely satisfactory for focal thickening of network lines, target globules and hyperpigmented areas; finally, it was fairly satisfactory for target network. Conclusion: The identification of dermoscopic features of CMN seems to show a good reproducibility, with a satisfactory intra- and interobserver agreement. Other studies involving a higher number of experienced and less experienced observers are requested to confirm these results.

Age- and Site-Specific Variation in the Dermoscopic Patterns of Congenital Melanocytic Nevi

To describe the dermoscopic features of congenital melanocytic nevi (CMN) and assess whether predominant dermoscopic patterns present in CMN are related to an individual's age (<12 years vs >or=12 years), sex, or lesional site (head, neck, and trunk vs extremities). Nonrandomized observational study. A total of 77 consecutive patients, each with 1 CMN (n = 77 lesions), from an outpatient dermatology clinic. A diagnosis of CMN was established by (1) documentation of a melanocytic nevus during the first year of life or (2) by clinical examination and either clinical history or biopsy findings. Images of CMN were evaluated for specific dermoscopic structures and patterns. The distribution of patterns was assessed by age, sex, and lesional site. Most of the 77 lesions exhibited 1 of the following predominant dermoscopic patterns: reticular (18 lesions [23%]), globular (14 [18%]), or reticuloglobular (12 [16%]). Globular CMN were present in 5 of the 19 individuals who were younger than 12 years (26%) but in only 9 of the 58 individuals 12 years or older (16%). Reticular CMN were seen exclusively in the individuals who were 12 years or older. Congenital melanocytic nevi exhibiting no predominant pattern were more commonly present in the individuals younger than 12 years. Globular CMN were present in 11 head, neck, and trunk lesions (30%) compared with 3 extremity lesions (8%). Conversely, reticular CMN were present in 16 extremity lesions (40%) compared with 2 head, neck, and trunk lesions (5%). The predominant dermoscopic pattern did not vary based on sex. The most commonly observed dermoscopic structures were globules (in 64 lesions [83%]), hypertrichosis (in 61 [79%]), and reticular networks (in 55 [71%]). Our results suggest that the predominant dermoscopic patterns of CMN vary according to age and lesional site. These differences may inform future studies on the pathogenesis of CMN.

Histologic features of congenital melanocytic nevi in infants 1 year of age or younger

Background: Congenital melanocytic nevi (CMN) occur in approximately 1% of the white population. These lesions are often surgically excised prophylactically because of increased melanoma risk. Objective: In this study 87 CMN of all sizes from infants 12 months of age or younger (mean age, 6.6 months) were examined histologically. Methods: Each lesion was evaluated for depth of nevus cell involvement, overall epidermal and dermal pattern, and cytologic atypia. Results: Most CMN involved the lower half of the reticular dermis (89%), and 51% infiltrated the subcutaneous tissue. Depth of nevus cell infiltration was positively correlated with size of the lesion. The predominant dermal pattern was diffuse interstitial infiltration (63%). Patchy nevus cell patterns were observed in 37% of the CMN and were associated with smaller lesions ( p < 0.001). Most of the CMN displayed no cytologic atypia (70%), and we found no cases of melanoma. Atypia was not significantly associated with either size or location of the nevus. Conclusion: These results indicate that depth and pattern of nevus cells are directly related to size of CMN in infants.