Clinical and Experimental Dermatology (1979) 4, 49.
Age-related changes in melanocytic naevi
JOHN C.MAIZE AND GERALD EOSTER Department of Dermatology, State University of New York at Buffalo, Buffalo, New U.S.A.
Accepted for publication 19 July 1978
The prevalence of melanocytic naevi in various age groups suggests a natural history characterized by a growth phase followed by a relatively long period of quiescence and eventual involution. In a clinical and histopathological study of pigmented lesions in 1058 newborn infants, Walton, Jacobs & Cox (1976) found that only i-oi/;, had melanocytic naevi. Other clinical studies have shown that the number of melanocytic naevi per person increases progressi;vely through childhood, adolescence and early adulthood (Stegmaier & Becker, 1960; Nicholls, 1968, 1973). Nicholls (1973) observed a peak number of moles at age 15 in males and at age 20-29 in females. Melanocytic naevi are almost universally present in young adults. The average number per person in this age group ranges from 15 to 40 (Pack, Lenson & Gerber, 1952; Stegmaier & Becker, 1963). With advancing age, there is a progressive decrease in the number of moles. In a painstaking histological study of all lesions suspected of being moles in a group of patients more than 50 years of age, Stegmaier found an average of only 4 naevi per person (Stegmaier, 1959). Nicholls (1973) observed that naevi rarely are present in persons aged 80 years. In addition to these epidemiological studies which indicate that naevi involute, a few instances of spontaneous disappearance of naevi without the halo phenomenon have been documented (Braitman, 1958; Shelley, i960). The present study was designed to determine the nature and statistical significance of histologic changes in melanocytic naevi with advancing age with particular attention to the reciprocal changes between the melanocytic component and the stroma. Materials and methods The gross features and histologic sections from 279 consecutive naevi submitted to this dermatopathology laboratory were studied. If more than one naevus was excised from the same Correspondence: Dr John C.Maize, 50 High Street—Suite # 1406, Buffalo, N.Y. 14203, U.S.A. 0307-6938/79/0300-0049502.00
© r979 Blackwell Scientific Publications
49
50
J.C.Maize and G.Foster
patient, each was treated separately. Blue naevi, balloon cell naevi, halo naevi and benign juvenile melanomas were excluded. Routine surgical material was used. Multiple slides were prepared from each block so in most instances at least 12 to 15 planes of section were studied. Additional sections were cut when necessary to characterize better a specific naevus. Special stains including the Verhoeff-Van Gieson, Masson trichrome. Wilder reticulin and Mowry colloidal iron before and after digestion with bovine testicular hyaluronidase were used to study stromal changes in selected cases. In each case, specific attention was given to the architecture of the naevus, distribution and density of the melanocytes, the presence or absence of neural changes, dermal fibrosis, fatty infiltration and mucin deposition. By architecture, the naevi were subdivided into three types which included flat or only slightly elevated, dome shaped and polypoid. Eor our purposes, dome shaped means that the diameter of the naevus is greater than its height above the surface of the surrounding skin whereas the reverse is true for polypoid naevi. According to the distribution of the nests of melanocytes, the naevi were subdivided into junction naevi, compound naevi and intradermal naevi. Naevi were judged to be intradermal if no evident nests of melanocytes were found at the dermo-epidermal junction after careful scrutiny of all the sections available. Compound naevi were further subdivided into two groups; Group i compound naevi were those that were preponderantly intradermal but had one or a few nests at the dermo-epidermal junction and Group II compound naevi were those that had several nests at the dermo-epidermal junction or were predominantly junctional. Although melanocytic naevi may arise at almost any age in some persons, extensive clinical surveys of the incidence of naevi {vide supra) clearly indicate that in the general population their onset follows a predictable age-related pattern. Patients usually cannot accurately state how long any individual naevus has been present. Eor the purposes of this study, therefore, the age at removal was used for statistical analysis rather than the patient's estimate of the length of time a naevus had been present. ' Observations
.
Sex and age distribution The 279 naevi were removed from 210 patients. 140 were women and 70 were men. This 2: i ratio of women to men is the same as that found by Winkelman & Rocha (1962) in their analysis of 1200 naevi. This probably represents a greater concern about their appearance among women than men since there is no difference in the incidence of naevi between sexes. Males accounted for 335% of intradermal naevi, 344% of Group I compound naevi and 33 3",, of Group II compound naevi, thus there was no sex difference in the types of naevi. The distribution of naevi by decade and sex is shown in Table i. Junctional proliferation One hundred and seventy (61 •2/,,) naevi were intradermal, 93 (33-4";,) were Group I compound naevi and 15 (5-4/0) were Group II compound naevi. Their distribution by decades is shown
Age-related changes in naevi Table r. Distribution of naevi by age and sex Age group (years) 40-49
10-19
20-29
Male
16
25
14
6
15
Female
14
36
65
25
22
Total
30
61
79
31
37
30
30-39
60-69
50-59
70-79
80-89
Total
16
I
0
14
2
3
94 184
3
3
278
in Table 2. Only one naevus was purely junctional when multiple sections were studied; this naevus was excluded because it was statistically insignificant. The mean age of the patients with intradermal naevi was 42-49 +1577 years. The mean age of the patients with Group I compound naevi was 3281 +13-91 years and that of the patients with Group II compound naevi was 1607 + 7-65 years. The mean age of the patients with Group I compound naevi differs significantly from that of the patients with intradermal naevi (P
Age-related changes in melanocytic naevi
JOHN C.MAIZE AND GERALD EOSTER Department of Dermatology, State University of New York at Buffalo, Buffalo, New U.S.A.
Accepted for publication 19 July 1978
The prevalence of melanocytic naevi in various age groups suggests a natural history characterized by a growth phase followed by a relatively long period of quiescence and eventual involution. In a clinical and histopathological study of pigmented lesions in 1058 newborn infants, Walton, Jacobs & Cox (1976) found that only i-oi/;, had melanocytic naevi. Other clinical studies have shown that the number of melanocytic naevi per person increases progressi;vely through childhood, adolescence and early adulthood (Stegmaier & Becker, 1960; Nicholls, 1968, 1973). Nicholls (1973) observed a peak number of moles at age 15 in males and at age 20-29 in females. Melanocytic naevi are almost universally present in young adults. The average number per person in this age group ranges from 15 to 40 (Pack, Lenson & Gerber, 1952; Stegmaier & Becker, 1963). With advancing age, there is a progressive decrease in the number of moles. In a painstaking histological study of all lesions suspected of being moles in a group of patients more than 50 years of age, Stegmaier found an average of only 4 naevi per person (Stegmaier, 1959). Nicholls (1973) observed that naevi rarely are present in persons aged 80 years. In addition to these epidemiological studies which indicate that naevi involute, a few instances of spontaneous disappearance of naevi without the halo phenomenon have been documented (Braitman, 1958; Shelley, i960). The present study was designed to determine the nature and statistical significance of histologic changes in melanocytic naevi with advancing age with particular attention to the reciprocal changes between the melanocytic component and the stroma. Materials and methods The gross features and histologic sections from 279 consecutive naevi submitted to this dermatopathology laboratory were studied. If more than one naevus was excised from the same Correspondence: Dr John C.Maize, 50 High Street—Suite # 1406, Buffalo, N.Y. 14203, U.S.A. 0307-6938/79/0300-0049502.00
© r979 Blackwell Scientific Publications
49
50
J.C.Maize and G.Foster
patient, each was treated separately. Blue naevi, balloon cell naevi, halo naevi and benign juvenile melanomas were excluded. Routine surgical material was used. Multiple slides were prepared from each block so in most instances at least 12 to 15 planes of section were studied. Additional sections were cut when necessary to characterize better a specific naevus. Special stains including the Verhoeff-Van Gieson, Masson trichrome. Wilder reticulin and Mowry colloidal iron before and after digestion with bovine testicular hyaluronidase were used to study stromal changes in selected cases. In each case, specific attention was given to the architecture of the naevus, distribution and density of the melanocytes, the presence or absence of neural changes, dermal fibrosis, fatty infiltration and mucin deposition. By architecture, the naevi were subdivided into three types which included flat or only slightly elevated, dome shaped and polypoid. Eor our purposes, dome shaped means that the diameter of the naevus is greater than its height above the surface of the surrounding skin whereas the reverse is true for polypoid naevi. According to the distribution of the nests of melanocytes, the naevi were subdivided into junction naevi, compound naevi and intradermal naevi. Naevi were judged to be intradermal if no evident nests of melanocytes were found at the dermo-epidermal junction after careful scrutiny of all the sections available. Compound naevi were further subdivided into two groups; Group i compound naevi were those that were preponderantly intradermal but had one or a few nests at the dermo-epidermal junction and Group II compound naevi were those that had several nests at the dermo-epidermal junction or were predominantly junctional. Although melanocytic naevi may arise at almost any age in some persons, extensive clinical surveys of the incidence of naevi {vide supra) clearly indicate that in the general population their onset follows a predictable age-related pattern. Patients usually cannot accurately state how long any individual naevus has been present. Eor the purposes of this study, therefore, the age at removal was used for statistical analysis rather than the patient's estimate of the length of time a naevus had been present. ' Observations
.
Sex and age distribution The 279 naevi were removed from 210 patients. 140 were women and 70 were men. This 2: i ratio of women to men is the same as that found by Winkelman & Rocha (1962) in their analysis of 1200 naevi. This probably represents a greater concern about their appearance among women than men since there is no difference in the incidence of naevi between sexes. Males accounted for 335% of intradermal naevi, 344% of Group I compound naevi and 33 3",, of Group II compound naevi, thus there was no sex difference in the types of naevi. The distribution of naevi by decade and sex is shown in Table i. Junctional proliferation One hundred and seventy (61 •2/,,) naevi were intradermal, 93 (33-4";,) were Group I compound naevi and 15 (5-4/0) were Group II compound naevi. Their distribution by decades is shown
Age-related changes in naevi Table r. Distribution of naevi by age and sex Age group (years) 40-49
10-19
20-29
Male
16
25
14
6
15
Female
14
36
65
25
22
Total
30
61
79
31
37
30
30-39
60-69
50-59
70-79
80-89
Total
16
I
0
14
2
3
94 184
3
3
278
in Table 2. Only one naevus was purely junctional when multiple sections were studied; this naevus was excluded because it was statistically insignificant. The mean age of the patients with intradermal naevi was 42-49 +1577 years. The mean age of the patients with Group I compound naevi was 3281 +13-91 years and that of the patients with Group II compound naevi was 1607 + 7-65 years. The mean age of the patients with Group I compound naevi differs significantly from that of the patients with intradermal naevi (P
