The biker‐glove pattern of congenital melanocytic nevi

Congenital melanocytic nevi (CMN) are common birthmarks with 20% occurring on the limbs. We describe 4 patients with acral CMN with a “biker‐glove” distribution with sparing of the distal digits, as has previously been described in acral infantile hemangiomas (IH). The existence of the biker‐glove pattern suggests that CMN arise from early mutations in melanocyte precursors and supports the recently described Kinsler‐Larue hypothesis of mesenchymal distribution of melanocyte migration occurring in a circular field from a central point. Developmental errors in mesenchymal precursors with similar migration patterns may explain this shared pattern among CMN and IH.     

Installation of a network for patients with congenital melanocytic nevi in German‐speaking countries

In 2005, an Internet‐based network for the support of patients with congenital melanocytic nevi in German‐speaking countries was started ( http://www.naevus‐netzwerk.de ). Along with detailed information for patients and parents, the home‐page includes a nevus registry which is based on an electronic questionnaire and which aims at providing data on the long‐term course of nevi estimated to reach > 10 cm in largest diameter. In the past, congenital melanocytic nevi have been subject to various mythological interpretations (“Tierfellnävus”, lit.”animal coat nevus”;”Muttermal”). Today an increasing body of reliable scientific data allows a differentiated reflection of the risk of malignant transformation and has led to progress in the diagnostic and therapeutic management. Recent findings from the literature and considerations from scientific meetings are reviewed.     

Varying proliferative and clonogenic potential in NRAS‐mutated congenital melanocytic nevi according to size

Congenital melanocytic nevi (CMN) are benign proliferations that may be associated with various consequences depending on their size. They are characterized by a specific molecular signature, namely a postzygotic somatic NRAS or BRAF mutation. We have recently reported that large CMN (lCMN), which are classically associated with an increased melanoma risk, harbour cell subpopulations with specific clonogenic and tumorigenic potential. We wished to ascertain whether cells displaying similar properties persisted postnatally in medium CMN (mCMN). Eighteen medium M1, nine large and one giant NRAS‐mutated CMN were prospectively included in the study. Subpopulations of mCMN cells expressed stem cell/progenitor lineage markers such as Sox10, nestin and Oct4, as was the case in lCMN. Nevertheless, conversely to lCMN, mCMN cells with clonogenic properties were rarer. In vitro, approximatively one in 1500 cells isolated from fresh mCMN formed colonies that could be passaged. In vivo, mCMN seemed to harbour cells with less proliferative potential than the larger lesions as lCMN biopsies displayed a threefold expansion compared to mCMN when xenografted in Rag2^?/? mice. Thus, our data revealed variations in clonogenicity and tumorigenic properties in NRAS‐mutated CMN according to size.     

Efficacy and safety of fumaric acid esters in the long‐term treatment of psoriasis – A retrospective study (FUTURE)

Background: This study collected data on the safety and efficacy of fumaric acid esters (FAE; Fumaderm^®) in the long‐term treatment of psoriasis. Patients and Methods: Patients were included at 163 dermatological centers if they either had been treated continuously with FAE for at least 24 months, or for 36 months with interruptions of no longer than 6 months. Data were reported from baseline, after 3, 6, 12, 24, and 36 or more months of therapy. Safety parameters were monitored and the severity of skin symptoms was assessed by “Physician's Global Assessment” (PGA) and “Psoriasis Area and Severity Index” (PASI). Results: 984 patients were included with a mean duration of 44 months of continuous treatment. The percentage of patients documented as markedly improved or clear was 67 % after six months, 78 % after 24 months, and 82 % after 36 months of therapy. Improvement was similar in patients with moderate and severe disease. Changes of laboratory parameters were usually insignificant and did not require a modification of FAE treatment in more than 90 % of the cases. Conclusions: In the long‐term treatment of patients with moderate and severe psoriasis FAE show a good and sustained clinical efficacy combined with a favorable safety profile.     

Age- and site-specific variation in the dermoscopic patterns of congenital melanocytic nevi: an aid to accurate classification and assessment of melanocytic nevi

OBJECTIVES: 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). DESIGN: Nonrandomized observational study. PATIENTS: 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. MAIN OUTCOME MEASURES: Images of CMN were evaluated for specific dermoscopic structures and patterns. The distribution of patterns was assessed by age, sex, and lesional site. RESULTS: 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%]). CONCLUSIONS: 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.     

Histological features and outcome of inverted type‐A melanocytic nevi

The presence of enlarged epithelioid/spindled nests located deep in the reticular dermis of a biphasic melanocytic neoplasm can mimic melanoma arising in a pre‐existing nevus, causing over‐interpretation of malignancy. We aimed to define the clinicopathologic significance of epithelioid/spindled nests in melanocytic nevi. Retrospectively using clinical and histologic information, we characterized 121 patients with a single lesion showing epithelioid/spindled melanocytes in the reticular dermis or subcutaneous fat, surrounded by melanophages, sometimes blending in with the adnexa. The majority of nevi occurred in women in the ages of 10 to 39 years, where the most frequent presentation was a changing mole. While 78% of the lesions displayed an anatomic (Clark’s) level of IV‐V, there was no ulceration, significant regression or inflammation. Up to 2 mitoses were found in only 12% of the cases, not correlating with the severity of cytological atypia. No recurrence or metastasis occurred during 45.5 months (mean) of clinical follow up in 26 patients. Notwithstanding the deep dermal extension, these findings suggest a benign histopathology and clinical outcome. Having compared the overlapping histopathology and clinical features between deep penetrating/clonal nevus and combined nevus, we posit that “inverted type‐A nevus” might be considered a variant of the two.     

Prevalence of melanocytic nevi in 8‐ to 10‐year‐old children in Southern Spain and analysis of associated factors

Background There is a known relationship between melanocytic nevi (MN) and cutaneous melanoma. MN are related to genetic and environmental factors, and the latter appear to be more important in childhood. Objectives To determine the prevalence of MN and its relationship with phenotypic traits and sun exposure habits in 8‐ to 10‐year‐old children. Subjects and methods We performed a cross‐sectional study of 8‐ to 10‐year‐old primary school children in the city of Granada (Spain), gathering data on phenotypic traits, sun protection measures, sunburn frequency and the number and density of MN. Results We detected a mean of 19.38 MN per child, predominantly <2 mm in diameter. MN count was associated with low phototype, and was higher in boys vs. girls with low phototype. MN were more numerous with higher age. The largest number of MN of all sizes was detected in 10‐year‐old boys. MN were most frequently located on the torso and other sites intermittently exposed to sunlight. Conclusions A higher MN count is associated with lower phototype (blonde hair and fair skin) and higher age. The mean number of MN, including those of smaller size (<2 mm), was elevated in our series, especially on intermittently exposed sites.     

Recent data on the risk of malignancy in congenital melanocytic nevi: the continuing debate on treatment

Congenital melanocytic nevi (CMN) have traditionally been considered a risk factor for the appearance of melanoma, but the true incidence of malignancy is unknown. Although various studies have attempted to quantify it, the results are highly variable and it is difficult to decide on the best therapeutic approach to take. Consequently, for some time the management of CMN has depended more on personal experience than on clear scientific evidence. The most recent studies performed in large patient series indicate that the risk of malignancy in CMN is much lower than expected and mainly affects large lesions involving the axial midline. In addition, it appears that a number of melanomas develop on the site of partially or completely excised lesions, or even away from the CMN itself, making the appropriateness of prophylactic surgery increasingly doubtful.