Patient age at the time of the first appearance of their MN ranged from 0 to 79 years. The majority of acquired nevi appeared in the second through fourth decades of life.
Length growth rate of congenital and acquired MN were shown in Figure 2. The median length growth rate of congenital and acquired MN were 2.0 and 1.6, respectively. To further study the relationship between length growth rate of congenital MN and age, we divided these patients into four age groups: 0 to 9, 10 to 19, 20 to 29, and ≥30 years; median values of length growth rate of each age group were 2.2, 2.0, 2.4, and 2.0, respectively.
The histologic subtypes of the excised nevi and the correlations between histologic subtype and body location are shown in Table 2. The most commonly excised nevi were intradermal nevi. Junctional nevi were less common, but ranked first in number in nevi removed from acral sites, which was confirmed with univariate multinomial logistic regression (odd ratio [OR], 95% confidence interval [CI]: 91.572 [52.210–160.959], P < 0.05). Acral location was also associated with a higher likelihood of compound nevi subtype (OR [95% CI]: 14.468 [8.981–23.306], P < 0.05).
The globular pattern was the most frequent component in nonacral nevi [Table 3, and Figure 3A], regardless of age [Table 4]. In acral MN, parallel furrow pattern and fibrillar pattern were commonest. The pseudonet work pattern was the second commonest on the head and neck [Figure 3B]. On other sites, globular and homogeneous patterns were also common. A pure reticular pattern was only seen in 6.9% (14/204) of patients.
In the acral region, parallel pattern was common in both junctional and compound MN, while irregular blotch pattern was frequently seen in nevi with dermal components and was the commonest pattern in intradermal nevi [Table 5].
This report describes the clinical, histologic, and dermoscopic features of nevi surgically removed from a series of patients in an academic dermatology center in China.
More than half of the patients required excision of their nevi out of malignant concerns without any suspicious malignant signs. This identified a public education gap for identifying suspicious melanocytic lesions and a need to promote patient education regarding MN and risk of melanoma, including visible signs of malignant transformation.
A female predominance was noted in our study, irrespective of nevus location. This may indicate a stronger concern not only with their appearance, but also with general skin health.
The prevalence of MN is related to age, race, and perhaps genetic and environmental factors. A few nevi are present at birth and in early childhood. The number then increases, reaching a peak during the third decade of life; thereafter, nevi tend to degenerate with increasing age. There is a period of particularly rapid development during puberty.[2,9] In the study, 54.7% (573/1046) of the patients developed nevi before 10 years of age, 70.2% (734/1046) before 20, and 83.2% (870/1046) before 30; this was in accordance with prior studies.
The incidence of MN on the palms and soles, nail beds and conjunctivae are correlated with race; nevi on these surfaces are more common in Africans and Asians than in Caucasians. In our Chinese series, most resected nevi were located on nonacral regions (79.2%, 829/1046) rather than on the palms and soles (20.8%, 217/1046). The high percentage of head and neck nevi being resected might be due to the visibility of nevi in these sites, triggering aesthetic or health concerns.
Of the 381 congenital nevi, 81.6% (311/381) were present at birth, and 18.4% (70/381) appeared during the first 2 years after birth. Parents often became worried after noticing obvious growth of these nevi in their children. As shown in Figure 2A, by the time surgical consultation is sought, 66.5% (212/319) congenital MN have increased by 0 to 3 times in length, 26.6% (85/319) by 4 to 10 times, and 2.8% (9/319) by more than 10 times (median value = 2.0). Furthermore, median values of length growth rate of the four age groups suggested that most congenital MN increased by 2.2 times in length between age 0 to 9 years, and then stayed relatively stable; this results in decreased ratio of nevus area/body surface area as the patient grow, which, in association with increased patient compliance, suggest that unless there is reasonable suspicion of malignancy, small and medium-sized nevi presented during 0 to 9 years of age be removed when the patient grows older. In large and giant congenital nevi, early removal might be beneficial due to elasticity of the skin and ease of closure.
According to Figure 2B, 82.7% (477/577) acquired MN have increased by 0 to 3 times in length, 6.1% (35/577) by 4 to 10 times, and 1.0% (6/577) by more than 10 times (median = 1.6) by the time surgery is considered. These observations regarding the trends of growth may provide patients an anticipation of the future sizes of their nevi, thus better informing decisions concerning nevi removal, especially in regards of cosmetic concerns.
Nevi of the head and neck and trunk were predominantly intradermal. Junctional nevi were more prevalent on acral sites, but more than half of all removed acral nevi were not junctional.
A previous study showed that facial nevi typically showed a pseudonetwork pattern intermingled by hairs. In our series, globular and pseudonetwork patterns were most frequently seen in MN of head and neck. In other locations (areas excluding acral region and head and neck), globular pattern was still the commonest pattern (34.8%, 71/204), with homogeneous pattern (21.1%, 43/204) ranking second. The globular pattern and its variants were the commonest pattern irrespective of age, a finding that differs from observations in Caucasian patients where it decreases with age and become uncommon after the age of 30 years.[1,11] Scope et al suggested that the presence of globular nevi in adults is concerning because such occurrence is unusual. The significance of our findings is that, in Chinese skin, the presence of a globular pattern in an older individual may be less alarming and less likely to trigger closer scrutiny or a biopsy.
Polymorphous blood vessel pattern has been incorporated in some dermoscopic algorithms designed to differentiate benign from malignant melanocytic lesions, with the presence of it being ominous.[13,14] In our series it was revealed that this pattern was not uncommon in benign lesions. In fact, 33.7% (58/172) of the nevi had three or more blood vessel patterns, although this pattern was seen nearly exclusively in dermal nevi. Vessel patterns were more commonly seen in MN located on head and neck than on other body sites [Table 3].
The present study was limited by the selection bias inherent in limiting findings to excised nevi. This bias may limit the ability to extrapolate our findings to nevi in Chinese skin generally. For example, it is possible that globular nevi were more likely to create patient anxiety than reticular nevi, resulting in a higher proportion of globular nevi in this study. Secondly, the length at onset of nevus was estimated by the patient, which may result in bias and imprecise data. In addition, this is a single center study that cannot necessarily represent the patterns expected in the whole population of China.
In conclusion, this report describes the clinical, histologic, and dermoscopic features of 1046 MN in a single-center series of Chinese patients. Most of these features are similar to those reported in Caucasian patients, but differences of potential clinical significance exist. Awareness of these differences might prove valuable when screening ethnically diverse groups of patients with melanocytic lesions.
The work was supported by grants from Clinical Characteristics and Application Research of Capital, Beijing Municipal Science and Technology Commission (No. Z121107001012162), and the National Natural Science Foundation of China (No. 81572675).
Conflicts of interest
1. Kincannon J, Boutzale C. The physiology of pigmented nevi. Pediatrics
1999; 104 (Pt 2):1042–1045.
2. Whiteman DC, Pavan WJ, Bastian BC. The melanomas: a synthesis of epidemiological, clinical, histopathological, genetic, and biological aspects, supporting distinct subtypes, causal pathways, and cells of origin. Pigment Cell Melanoma Res
2011; 24:879–897. doi: 10.1111/j.1755-148X.2011.00880.x.
3. Carli P, Massi D, Santucci M, Biggeri A, Giannotti B. Cutaneous melanoma
histologically associated with a nevus
de novo have a different profile of risk: results from a case-control study. J Am Acad Dermatol
1999; 40:549–557. doi: 10.1016/S0190-9622(99)70436-6.
4. Carrera C, Marchetti MA, Dusza SW, Argenziano G, Braun RP, Halpern AC, et al. Validity and reliability of dermoscopic criteria used to differentiate nevi from melanoma
: a web-based international dermoscopy
society study. JAMA Dermatol
2016; 152:798–806. doi: 10.1001/jamadermatol.2016.0624.
5. Tognetti L, Cevenini G, Moscarella E, Cinotti E, Farnetani F, Mahlvey J, et al. An integrated clinical-dermoscopic risk scoring system for the differentiation between early melanoma
and atypical nevi: the iDScore. J Eur Acad Dermatol Venereol
2018; 32:2162–2170. doi: 10.1111/jdv.15106.
6. Tognetti L, Cinotti E, Moscarella E, Farnetani F, Malvehy J, Lallas A, et al. Impact of clinical and personal data in the dermoscopic differentiation between early melanoma
and atypical nevi. Dermatol Pract Concept
2018; 8:324–327. doi: 10.5826/dpc.0804a16.
7. Bradford PT, Goldstein AM, McMaster ML, Tucker MA. Acral lentiginous melanoma
: incidence and survival patterns in the United States, 1986–2005. Arch Dermatol
2009; 145:427–434. doi: 10.1001/archdermatol.2008.609.
8. Cress RD, Holly EA. Incidence of cutaneous melanoma
among non-Hispanic whites, Hispanics, Asians, and blacks: an analysis of california cancer registry data, 1988–93. Cancer Causes Control
1997; 8:246–252. doi: 10.1023/A:1018432632528.
9. Maize JC, Foster G. Age-related changes in melanocytic naevi. Clin Exp Dermatol
1979; 4:49–58. doi: 10.1111/j.1365-2230.1979.tb01590.x.
10. Argenziano G, Soyer HP, Chimenti S, Talamini R, Corona R, Sera F, et al. Dermoscopy
of pigmented skin lesions: results of a consensus meeting via the Internet. J Am Acad Dermatol
2003; 48:679–693. doi: 10.1067/mjd.2003.281.
11. Zalaudek I, Grinschgl S, Argenziano G, Marghoob AA, Blum A, Richtig E, et al. Age-related prevalence of dermoscopy
patterns in acquired melanocytic naevi. Br J Dermatol
2006; 154:299–304. doi: 10.1111/j.1365-2133.2005.06973.x.
12. Scope A, Marchetti MA, Marghoob AA, Dusza SW, Geller AC, Satagopan JM, et al. The study of nevi in children: Principles learned and implications for melanoma
diagnosis. J Am Acad Dermatol
2016; 75:813–823. doi: 10.1016/j.jaad.2016.03.027.
13. Henning JS, Dusza SW, Wang SQ, Marghoob AA, Rabinovitz HS, Polsky D, et al. The CASH (color, architecture, symmetry, and homogeneity) algorithm for dermoscopy
. J Am Acad Dermatol
2007; 56:45–52. doi: 10.1016/j.jaad.2006.09.003.
14. Argenziano G, Catricala C, Ardigo M, Buccini P, De Simone P, Eibenschutz L, et al. Seven-point checklist of dermoscopy
revisited. Br J Dermatol
2011; 164:785–790. doi: 10.1111/j.1365-2133.2010.10194.x.
Keywords:© 2019 Chinese Medical Association
Nevus; Melanoma; Dermoscopy