Background: Melanotic pigmentations in scars consecutive to the excision of melanocytic tumours can be secondary to a reactive phenomenon related to the scar tissue or to a recurrence of the melanocytic lesion excised...Background: Melanotic pigmentations in scars consecutive to the excision of melanocytic tumours can be secondary to a reactive phenomenon related to the scar tissue or to a recurrence of the melanocytic lesion excised in the first case. Recurrent naevi may sometimes adopt unusual features that make them difficult to differentiate from a melanoma. Objectives: To describe the clinical, dermoscopic and histological features of melanotic pigmentations in scars consecutive to the excision of melanocytic tumours, and to correlate the histological diagnosis with the dermoscopic features. Methods: This was a prospective cohortstudy using macrophotography, dermoscopy and histopatho- logical study. Ninety-five melanotic pigmentations (77 patients) in scars secondary to the excision of melanocytic tumours were prospectively collected in the Department of Dermatology at the Instituto Valenciano de Oncologa in Valencia, Spain. Histopathological study was performed in 57 scars. Results: Thirteen dermoscopic structures were identified. Four criteria allowed a differentiation between reactive and specific melanocytic pigmentations. Presence of globules and presence of heterogeneous pigmentation were features associated with specific melanocytic pigmentations (P < 0.0001). Presence of a regular network and presence of streaks weremore frequently found in reactive pigmentations (P = 0.023 and 0.026, respectively). Conclusions: Dermoscopic examination of melanotic pigmentations in excision scars of melanocytic tumours provides useful information about the origin of that pigmentation. Based on such information, recurrent naevi can be differentiated from reactive pigmentations in most cases. Excision and histopathological diagnosis continue to be imperative in some cases of recurrent naevi with atypical clinical features.展开更多
Background: The association of melanoma with HLA class II loci is under extensive debate. Different investigators have found discrepant results due to, at least in part, sample size, patient series heterogeneity, choi...Background: The association of melanoma with HLA class II loci is under extensive debate. Different investigators have found discrepant results due to, at least in part, sample size, patient series heterogeneity, choice of control population and differences in the techniques employed for the detection of HLA antigens and alleles. Objectives: This study was designed to analyse the possible association of melanoma with HLA class II loci with regard to different clinic pathological factors and to investigate other risk factors for melanoma susceptibility, such as HLA homozygosity. Patients and methods: HLA-DRB1,-DQA1 and -DQB1 genotyping was performed for 117 eastern Spanish patients presenting with primary melanoma. Results: Although there were no significant alterations in the phenotypic frequencies of HLA-DQA1, -DQB1 or -DRB1 alleles in any subgroup of patients when compared with controls, patients exhibited a statistically significant increase in HLA-DQA1 homozygosity rate. This DQA1 homozygosity-specific association was particularly dependent on some features in melanoma patients such as light hair colour, skin type I or II, early age at diagnosis, absence of atypical naevi, or abscence of atypical naevus syndrome phenotype (aetiological fractions about 10-20%). Analysis of homozygosity for single DQA1 alleles showed an increased homozygosity rate for DQA1*0505 and DQA1*0301 in comparison with controls. These DQA1 alleles are in strong linkage disequilibrium with DQB1*0301 in white populations, and DQB1*0301 homozygous individuals were significantly increased in red in or fair-haired patients (relative risk 5.65). Conclusions: Our results indicate that the contribution of HLA class II alleles to primary melanoma incidence is not significant in the Spanish population. However, homozygosity for the HLA-DQA1 locus (and,perhaps, for the HLA-DQB1*0301 allele) might be considered a potential risk factor for developing melanoma depending on the person’s genetic background and,perhaps, on certain environmental conditions.展开更多
文摘Background: Melanotic pigmentations in scars consecutive to the excision of melanocytic tumours can be secondary to a reactive phenomenon related to the scar tissue or to a recurrence of the melanocytic lesion excised in the first case. Recurrent naevi may sometimes adopt unusual features that make them difficult to differentiate from a melanoma. Objectives: To describe the clinical, dermoscopic and histological features of melanotic pigmentations in scars consecutive to the excision of melanocytic tumours, and to correlate the histological diagnosis with the dermoscopic features. Methods: This was a prospective cohortstudy using macrophotography, dermoscopy and histopatho- logical study. Ninety-five melanotic pigmentations (77 patients) in scars secondary to the excision of melanocytic tumours were prospectively collected in the Department of Dermatology at the Instituto Valenciano de Oncologa in Valencia, Spain. Histopathological study was performed in 57 scars. Results: Thirteen dermoscopic structures were identified. Four criteria allowed a differentiation between reactive and specific melanocytic pigmentations. Presence of globules and presence of heterogeneous pigmentation were features associated with specific melanocytic pigmentations (P < 0.0001). Presence of a regular network and presence of streaks weremore frequently found in reactive pigmentations (P = 0.023 and 0.026, respectively). Conclusions: Dermoscopic examination of melanotic pigmentations in excision scars of melanocytic tumours provides useful information about the origin of that pigmentation. Based on such information, recurrent naevi can be differentiated from reactive pigmentations in most cases. Excision and histopathological diagnosis continue to be imperative in some cases of recurrent naevi with atypical clinical features.
文摘Background: The association of melanoma with HLA class II loci is under extensive debate. Different investigators have found discrepant results due to, at least in part, sample size, patient series heterogeneity, choice of control population and differences in the techniques employed for the detection of HLA antigens and alleles. Objectives: This study was designed to analyse the possible association of melanoma with HLA class II loci with regard to different clinic pathological factors and to investigate other risk factors for melanoma susceptibility, such as HLA homozygosity. Patients and methods: HLA-DRB1,-DQA1 and -DQB1 genotyping was performed for 117 eastern Spanish patients presenting with primary melanoma. Results: Although there were no significant alterations in the phenotypic frequencies of HLA-DQA1, -DQB1 or -DRB1 alleles in any subgroup of patients when compared with controls, patients exhibited a statistically significant increase in HLA-DQA1 homozygosity rate. This DQA1 homozygosity-specific association was particularly dependent on some features in melanoma patients such as light hair colour, skin type I or II, early age at diagnosis, absence of atypical naevi, or abscence of atypical naevus syndrome phenotype (aetiological fractions about 10-20%). Analysis of homozygosity for single DQA1 alleles showed an increased homozygosity rate for DQA1*0505 and DQA1*0301 in comparison with controls. These DQA1 alleles are in strong linkage disequilibrium with DQB1*0301 in white populations, and DQB1*0301 homozygous individuals were significantly increased in red in or fair-haired patients (relative risk 5.65). Conclusions: Our results indicate that the contribution of HLA class II alleles to primary melanoma incidence is not significant in the Spanish population. However, homozygosity for the HLA-DQA1 locus (and,perhaps, for the HLA-DQB1*0301 allele) might be considered a potential risk factor for developing melanoma depending on the person’s genetic background and,perhaps, on certain environmental conditions.
