Early Melanomas Dermoscopically Characterized by Reticular Depigmentation

Dermoscopic and clinical features of pigmented skin lesions of the genital area

BACKGROUND

The dermoscopic features of vulvar melanosis lesions are well known. To our knowledge, there are only a few case reports about dermoscopic features of pigmented genital lesions in male patients.

OBJECTIVE

To evaluate dermoscopic and clinical characteristics of benign lesions of the genital area in both males and females, and to assess the distinguishing dermoscopic criteria of vulvar melanosis and atypical melanocytic nevi of the genital type.

METHODS

68 patients with pigmented genital lesions were included in this observational study (28 male and 40 female). A punch biopsy was taken from all pigmented lesions and histopathological examination was performed on all specimens.

RESULTS

We histopathologically diagnosed: genital melanosis in 40 lesions, atypical melanocytic nevi of the genital type in 15 lesions, melanocytic nevi in 9 lesions, seborrheic keratosis in 4 lesions. The most frequent locations were the glans penis (19 patients, 67.9%) in males and the labia minora (19 patients, 47.5%) in females. The mean age of patients with atypical nevi (28,6 ± 11,36) was significantly lower than the mean age of patients with genital melanosis (47,07 ± 15,33).

CONCLUSIONS

Parallel pattern is prominent in genital melanosis, ring-like pattern is only observed in genital melanosis. Most pigmented lesions on the genital area are solitary. Blue-white veil and irregular dots are only observed in AMNGT. According to these results, we propose that histopathological examination is performed, especially if blue-white veil and irregular dots are found by dermoscopy.

Negative pigment network and shiny white streaks: a dermoscopic-pathological correlation study

It has been suggested that both negative pigment network (NPN) and shiny white streaks (SWS) were related to an increase of dermal collagen. To study precisely the dermoscopic-histopathologic correlation of NPN and SWS, we have performed a dermoscopic-pathological correlation study. A total of 25 skin lesions dermoscopically characterized by the presence of NPN and/or SWS, including histopathologically confirmed dermatofibroma (2), Spitz nevus (3), compound nevus (6), dysplastic nevus (7), and melanoma (7), were evaluated for the presence of NPN, SWS, and blue-white veil. The histopathologic features such as orthokeratosis, orthokeratosis plus nests of pigmented melanocytes at the junction, hypergranulosis, hypergranulosis plus nests of pigmented melanocytes at the junction, epidermal invagination plus orthokeratosis, fibrosis, lamellar fibrosis, and elongation and bridging of rete ridges were evaluated. We found a disagreement in 80% of skin lesions between NPN and fibrosis (P = 0.02). For SWS, a significant agreement emerged with hypergranulosis (76%; P = 0.01), and the same occurred with fibrosis (80%; P = 0.01). Moreover, blue-white veil also displayed a significant agreement with hypergranulosis (68%; P = 0.04). Our findings confirm the correlation of SWS with fibrosis, whereas a clear-cut histopathologic substrate of NPN could not be established.

Dermoscopic features of cutaneous melanoma are associated with clinical characteristics of patients and tumours and with MC1R genotype

BACKGROUND

Several algorithms are available for the dermoscopic diagnosis of pigmented skin lesions. The MC1R gene is a key determinant of pigmentation characteristics that are established host-related melanoma risk factors.

OBJECTIVES

To investigate the association of dermoscopic features of sporadic cutaneous melanomas with clinical characteristics of patients and corresponding tumours and with genetic changes in the MC1R and BRAF genes.

METHODS

A total of 64 dermoscopic images of 62 patients were scored by ABCD rule and modified pattern analysis. Detailed patients' and melanomas' characteristics were collected. Patients were screened for germline MC1R variants and related melanomas for somatic V600 BRAF mutations.

RESULTS

A lower total dermoscopic score (TDS) was observed in melanomas of patients with red hair (P = 0.019), due to reduced dermoscopic structures (P < 0.0001). Thicker melanomas showed higher TDS values (P = 0.021) due to sharper borders (P < 0.0001) and higher number of colors (P = 0.004). An atypical pigment network was prevalent in superficial spreading melanomas (P = 0.010), in individuals with dark skin (P = 0.043) and hair color (P = 0.001). An atypical vascular pattern was more frequent in nodular (P < 0.0001) and thick (P < 0.0001) melanomas, in individuals with skin type I-II (P = 0.037), blond or red hair color (P = 0.032) and blue or green eyes (P = 0.014). Melanomas of MC1R R carriers showed lower TDS value (P = 0.037), reduced dermoscopic structures (P = 0.001) and lower prevalence of atypical pigment network (P = 0.001). No differences were identified between BRAF-mutated or wild-type melanomas.

CONCLUSIONS

We suggest a phenotypic/MC1R profile for melanoma patients and their tumours. Melanomas of MC1R R carriers show a significant lower TDS value, with reduced dermoscopic structures, and a lower prevalence of an atypical pigment network. Non-carriers of MC1R R variants develop melanomas dermoscopically characterized by an atypical pigment network which is prevalent in superficial spreading melanomas, in patients with dark complexion and less frequent in red-haired individuals.

Typical and atypical dermoscopic presentations of dermatofibroma

BACKGROUND

Dermatofibroma is a common skin neoplasm that is usually easy to recognize, but in some cases its differentiation from melanoma and other tumours may be difficult.

OBJECTIVE

To describe the dermoscopic features of dermatofibromas, with special emphasis on the characteristics of atypical patterns, and to calculate pattern frequency according to the patients age and gender, anatomical site and histopathological subtype.

METHODS

Two groups of patients were consecutively seen, one with dermatofibromas that were surgically excised because of clinically and/or dermoscopically equivocal aspects or following patient request, and another with non-equivocal dermatofibromas. Each lesion was scored for previously reported global dermoscopic patterns and for additional features.

RESULTS

A typical pattern was observed in 92 of 130 (70.8%) lesions, whereas an atypical pattern, that we named the 'non Dermatofibroma (DF)-like' pattern, was seen in 38 of 130 (29.2%). Atypical dermatofibromas showed features reminiscent of different conditions, such as melanoma in 21(16.2%) cases, vascular tumour in six (4.6%), basal cell carcinoma in five (3.8%), collision tumour in three (2.3%) and psoriasis in three (2.3%). A significant association was found between the 'melanoma-like' pattern/'vascular tumour-like' pattern and males, whereas a trend was observed between the above-mentioned patterns and hemosiderotic/aneurysmal DFs. 'Peripheral pigment network and central white scar-like patch' pattern was found associated with females and classic histopathological variant of DF.

CONCLUSION

Dermatofibromas may display different morphological faces. The typical dermoscopic patterns allow a confident diagnosis, whereas a full surgical excision is always recommended in all doubtful cases.

Negative pigment network: an additional dermoscopic feature for the diagnosis of melanoma

BACKGROUND

The negative pigment network (NPN) is seen as a negative of the pigmented network and it is purported to be a melanoma-specific structure.

OBJECTIVES

We sought to assess the frequency, sensitivity, specificity, and odds ratios (ORs) of NPN between melanoma cases and a group of control lesions.

METHODS

Digitalized images of skin lesions from 679 patients with histopathological diagnosis of dermatofibroma (115), melanocytic nevus (220), Spitz nevus (139), and melanoma (205) were retrospectively collected and blindly evaluated to assess the presence/absence of NPN.

RESULTS

The frequency of occurrence of NPN was higher in the melanoma group (34.6%) than in Spitz nevus (28.8%), melanocytic nevus (18.2%), and dermatofibroma (11.3%) groups. An OR of 1.8 emerged for the diagnosis of melanoma in the presence of NPN as compared with nonmelanoma diagnosis. Conversely, for melanocytic nevi and dermatofibromas the OR was very low (0.5 and 0.3, respectively). For Spitz nevi the OR of 1.1 was not statistically significant. When comparing melanoma with dermatofibroma, melanocytic nevus, and Spitz nevus, we observed a significantly higher frequency of multicomponent pattern (68.1%), asymmetric pigmentation (92.9%), irregularly distributed NPN (87.3%), and peripheral location of NPN (66.2%) in melanomas.

LIMITATIONS

Further studies can provide the precise dermoscopic-histopathologic correlation of NPN in melanoma and other lesions.

CONCLUSIONS

The overall morphologic pattern of NPN, such as the irregular distribution and the peripheral location of NPN, along with the multicomponent pattern and the asymmetric pigmentation could be used as additional features in distinguishing melanoma from Spitz nevus and other benign lesions.

Variegated dermoscopy of in situ melanoma

BACKGROUND

Melanomas in situ (MIS) are difficult to diagnose, lacking well-established dermoscopic descriptors.

OBJECTIVE

The aim of this study was to improve the identification of early melanomas describing the variegated dermoscopic features of MIS and their correlation with demographic and clinical aspects.

METHODS

Dermoscopic images of 114 histologically proven MIS were evaluated by 3 expert dermoscopists and classified into their main dermoscopic patterns. Dermoscopic features were also considered for their correlation with clinical parameters.

RESULTS

Eight different dermoscopic subtypes of MIS were identified: reticular grey-blue (27.2%), reticular (21.1%), multicomponent (20.2%), island (10.5%), spitzoid (7%), inverse network (6.1%), 'net-blue globules' (5.3%) and globular (2.6%). Clinical characteristics of lesions and patients varied according to the different dermoscopic groups.

CONCLUSION

We hypothesize that the different dermoscopic subgroups of MIS correspond to lesions with a different origin and, possibly, various patterns of growth and a different biological behaviour.

Dermoscopy of pigmented lesions of the vulva: a retrospective morphological study

BACKGROUND

The dermoscopic patterns of pigmented skin tumors are influenced by the body site.

OBJECTIVE

To evaluate the clinical and dermoscopic features associated with pigmented vulvar lesions.

METHODS

Retrospective analysis of clinical and dermoscopic images of vulvar lesions. The χ² test was used to test the association between clinical data and histopathological diagnosis.

RESULTS

A total of 42 (32.8%) melanocytic and 86 (67.2%) nonmelanocytic vulvar lesions were analyzed. Nevi significantly prevailed in younger women compared with melanomas and melanosis and exhibited most commonly a globular/cobblestone (51.3%) and a mixed (21.6%) pattern. Dermoscopically all melanomas showed a multicomponent pattern. Melanotic macules showed clinical overlapping features with melanoma, but their dermoscopic patterns differed significantly from those observed in melanomas.

CONCLUSION

The diagnosis and management of pigmented vulvar lesions should be based on a good clinicodermoscopic correlation. Dermoscopy may be helpful in the differentiation of solitary melanotic macules from early melanoma.