Topical therapy for regression and melanoma prevention of congenital giant nevi.

Giant congenital melanocytic nevi are NRAS-driven proliferations that may cover up to 80% of the body surface. Their most dangerous consequence is progression to melanoma. This risk often triggers preemptive extensive surgical excisions in childhood, producing severe lifelong challenges. We have presented preclinical models, including multiple genetically engineered mice and xenografted human lesions, which enabled testing locally applied pharmacologic agents to avoid surgery. The murine models permitted the identification of proliferative versus senescent nevus phases and treatments targeting both. These nevi recapitulated the histologic and molecular features of human giant congenital nevi, including the risk of melanoma transformation. Cutaneously delivered MEK, PI3K, and c-KIT inhibitors or proinflammatory squaric acid dibutylester (SADBE) achieved major regressions. SADBE triggered innate immunity that ablated detectable nevocytes, fully prevented melanoma, and regressed human giant nevus xenografts. These findings reveal nevus mechanistic vulnerabilities and suggest opportunities for topical interventions that may alter the therapeutic options for children with congenital giant nevi.

Phacomatosis pigmentokeratotica: Exploring extracutaneous comorbidities and topical therapy.

Phacomatosis pigmentokeratotica (PPK) is a RASopathy characterized by the presence of a sebaceous nevus and a papular speckled lentiginous nevus. This case report highlights the associated extracutaneous comorbidities, including life-threatening arrhythmia, and introduces topical rapamycin as a potential therapeutic avenue for sebaceous nevus in PPK patients.

Significant improvement of a nevus spilus-type congenital melanocytic nevus with oral selumetinib.

Giant congenital melanocytic nevi (GCMN) can be cosmetically significant and can lead to melanoma. There is no standard pharmacologic treatment for GCMN. We present the case of an 8-year-old female with kaposiform lymphangiomatosis caused by an NRAS mutation whose nevus spilus-type GCMN improved on oral selumetinib.

Dermatologic toxicities to immune checkpoint inhibitor therapy: A review of histopathologic features.

Antineoplastic agents that use the immune system have revolutionized cancer treatment. Specifically, implementation of immune checkpoint inhibitors, monoclonal antibodies that block cytotoxic T-lymphocyte-associated antigen-4, programmed cell death protein 1, or programmed cell death ligand 1 show improved and sustained responses in patients with cancer. However, these agents are associated with a plethora of adverse events, many manifesting in the skin. As the clinical application of cancer immunotherapies expands, understanding the clinical and histopathologic features of associated cutaneous toxicities becomes increasingly important to dermatologists, oncologists, and pathologists to ensure timely diagnosis and appropriate care. This review discusses cutaneous reactions to immune checkpoint inhibitors, focusing on histopathologic features.

Dermoscopic monitoring of efficacy of ingenol mebutate in the treatment of pigmented and non-pigmented basal cell carcinomas.

Basal cell carcinoma is the most common non-melanoma skin cancer, and its incidence continues to raise. Although surgery can be considered the mainstay of therapy, new current pharmacological options are available and focus on tumor eradication, maximizing cosmetic results, and functional capacity. Several studies have recently reported on safety and efficacy of topical ingenol mebutate gel, a derivative of the plant Euphorbia Peplus, used to treat actinic keratosis and superficial basal cell carcinoma. In our knowledge, we report for the first time the dermoscopic evaluation of outcome and monitoring of superficial pigmented and non-pigmented basal cell carcinomas in four patients treated by this novel non-ablative agent. Ingenol mebutate gel therapy has showed to be effective and without important side-effects for pigmented and non-pigmented superficial basal cell carcinomas. We emphasize the usefulness of dermoscopy in supporting the clinical diagnosis and excluding the presence of tumor residue or recurrence. In a future scenario, we hope it will be soon possible to follow-up the lesions, after treatment, avoiding post-control biopsy punch.

Congenital melanocytic nevi: update in genetics and management.

PURPOSE OF REVIEW: The article intends to review recent updates in the management of congenital melanocytic nevi (CMN) and the evolving genomic landscape that has begun to shed light on the nature of nevogenesis, malignant potential, and possible therapeutic targets for those with melanoma and neurologic involvement. RECENT FINDINGS: CMN are the result of postzygotic somatic mutations involving key proteins in the mitogen-activated protein kinase pathway, primarily NRAS and BRAF. Complications include a spectrum of neurologic findings and development of melanoma. Patients with extracutaneous involvement may be better termed as having 'CMN syndrome'. MRI findings in high risk patients with multiple CMN may best predict clinical outcome. SUMMARY: The management of patients with CMN is complex. Neurologic involvement and melanoma remain the two most devastating complications. New, genetically targeted therapies for patients with complications may be of value, and research for potential therapies is ongoing.

Cutaneous skeletal hypophosphatemia syndrome (CSHS) is a multilineage somatic mosaic RASopathy.

BACKGROUND: We recently demonstrated multilineage somatic mosaicism in cutaneous skeletal hypophosphatemia syndrome (CSHS), which features epidermal or melanocytic nevi, elevated fibroblast growth factor (FGF)-23, and hypophosphatemia, finding identical RAS mutations in affected skin and bone. OBJECTIVE: We sought to: (1) provide an updated overview of CSHS; (2) review its pathobiology; (3) present a new patient with CSHS; and (4) discuss treatment modalities. METHODS: We searched PubMed for "nevus AND rickets," and "nevus AND hypophosphatemia," identifying cases of nevi with hypophosphatemic rickets or elevated serum FGF-23. For our additional patient with CSHS, we performed histopathologic and radiographic surveys of skin and skeletal lesions, respectively. Sequencing was performed for HRAS, KRAS, and NRAS to determine causative mutations. RESULTS: Our new case harbored somatic activating HRAS p.G13 R mutation in affected tissue, consistent with previous findings. Although the mechanism of FGF-23 dysregulation is unknown in CSHS, interaction between FGF and MAPK pathways may provide insight into pathobiology. Anti-FGF-23 antibody KRN-23 may be useful in managing CSHS. LIMITATIONS: Multilineage RAS mutation in CSHS was recently identified; further studies on mechanism are unavailable. CONCLUSION: Patients with nevi in association with skeletal disease should be evaluated for serum phosphate and FGF-23. Further studies investigating the role of RAS in FGF-23 regulation are needed.

Melanocytic nevi excised during B-Raf proto-oncogene (BRAF) inhibitor therapy: A study of 19 lesions from 10 patients.

BACKGROUND: There are limited descriptions of histopathology and immune profiles of new or changing melanocytic nevi in the setting of B-Raf proto-oncogene (BRAF) inhibitor therapy. OBJECTIVE: We sought to identify their distinctive features. METHODS: Clinical charts and histologic review, neuroblastoma RAS viral (v-ras) oncogene homolog genotyping, and immunohistochemistry for HMB-45, BRAFV600E, phosphorylated extracellular signal-regulated kinase (pERK), phosphorylated protein kinase B, CD4, and CD8 were performed on 19 melanocytic nevi from 10 patients and 23 control nevi. RESULTS: BRAF inhibitors were administered for metastatic melanoma (7), colonic adenocarcinoma (2), and papillary thyroid carcinoma (1). The average duration of BRAF inhibition before lesion excision was 8 months. Frequently associated histologic features included pigmentation of the stratum corneum, hyperpigmented keratinocytes, dermal melanophages, and deep HMB-45 expression. The lesions were BRAFV600E and neuroblastoma RAS viral (v-ras) oncogene homolog wild-type, expressed diffuse weak-moderate pERK, and possessed a predominance of CD8(+) in comparison with CD4(+) T lymphocytes within the dermal infiltrates. LIMITATION: This is a retrospective study of a small and heterogeneous group. CONCLUSION: The nevi associated with BRAF inhibitor therapy invariably lack BRAFV600E mutation. BRAF inhibition appears to cause an increased cytotoxic T-cell response and increased mitogen-activated protein kinase activity in BRAF wild-type lesions, supported by pERK expression, possibly resulting in an activated phenotype characterized by increased melanin pigmentation and deep HMB-45 expression.

Dermoscopic changes in melanocytic nevi in patients receiving immunosuppressive and biologic treatments: results of a prospective case-control study.

BACKGROUND: The immune system restrains benign melanocytic lesions, however the relationship between immunosuppression and changes in nevi is not known. OBJECTIVES: We sought to investigate the development of new nevi in patients using immunosuppressive agents, to evaluate any size or dermoscopic changes in existent nevi, and to evaluate any risk of developing melanoma. METHODS: There were 266 melanocytic lesions in 103 patients undergoing immunosuppressive therapy and 180 melanocytic lesions matched for age, sex, race, and Fitzpatrick skin type in 60 healthy control subjects. RESULTS: Nevus counts increased from baseline in the treatment group (P < .001) as did nevus size (P = .046) but the increase compared with the control group only remained statistically significant for nevus numbers (P = .001). There was a statistically significant appearance of dermoscopic changes in the nevi of immunosuppressed patients compared with healthy control subjects (P < .001). Ten lesions were excised including 6 because of significant dermoscopic change during treatment and all were benign. LIMITATIONS: Follow-up duration was short and the number of patients was small. CONCLUSION: Immunosuppressive therapy was associated with increased nevus counts and changed dermoscopic appearance but as none of the changed and subsequently excised nevi were malignant, continued monitoring for invasive features is a reasonable alternative to excision.

Agminated flexural melanocytic nevi: a late sequela of Langerhans cell histiocytosis?

Agminated flexural melanocytic nevi in children with a history of Langerhans cell histiocytosis (LCH) are rare and thought to be coincidental or related to systemic chemotherapy. We report on an 11-year-old boy in remission from LCH, treated with only topical steroids, who presented years later with an eruption of melanocytic nevi in the bilateral inguinal and axillary regions. Rather than coincidence, we hypothesize that agminated flexural melanocytic nevi are a late sequela of LCH, possibly resulting from immune tolerance or a reaction to local inflammation.

Congenital Melanocytic Nevus of the Nose Removed Using Dermabrasion, Hydroquinone, and Serial Excision.

We report a child with a congenital pigmented nevus of the nose involving the left ala, sidewall, soft triangle, and tip. Removal of the lesion was performed using dermabrasion, topical hydroquinone, and serial excision to optimize the aesthetic outcome. The patient was left with a linear scar and did not require reconstruction with a skin graft or flap.

Extensive nevus comedonicus involving the palm: questionable role of the pilosebaceous unit in pathogenesis.

A 10-year-old boy had multiple grouped pits with black plugs arranged along the lines of Blaschko on his left chest, arm, and palm. Involvement of the palms is rarely reported in the literature. Recent reports have described mosaic acneiform conditions that could share pathogenetic mechanisms with nevus comedonicus. We briefly review the literature on mosaic conditions with acneiform lesions including nevus comedonicus.

Mosaic BRAF Fusions Are a Recurrent Cause of Congenital Melanocytic Nevi Targetable by MAPK Pathway Inhibition.

Among children with multiple congenital melanocytic nevi, 25% have no established genetic cause, of whom many develop a hyperproliferative and severely pruritic phenotype resistant to treatment. Gene fusions have been reported in individual cases of congenital melanocytic nevi. We studied 169 patients with congenital melanocytic nevi in this study, 38 of whom were double wild type for pathogenic NRAS/BRAF variants. Nineteen of these 38 patients had sufficient tissue to undergo RNA sequencing, which revealed mosaic BRAF fusions in 11 of 19 patients and mosaic RAF1 fusions in 1 of 19. Recurrently, fusions involved the loss of the 5´ regulatory domain of BRAF or RAF1 but preserved the kinase domain. We validated all cases and detected the fusions in two separate nevi in 5 of 12 patients, confirming clonality. The absence of the fusion in blood in 8 of 12 patients indicated mosaicism. Primary culture of BRAF-fusion nevus cells from 3 of 12 patients demonstrated highly increased MAPK activation, despite only mildly increased BRAF expression, suggesting additional mechanisms of kinase activation. Trametinib quenched MAPK hyperactivation in vitro, and treatment of two patients caused rapid improvement in bulk tissue, improving bodily movement and reducing inflammation and severe pruritus. These findings offer a genetic diagnosis to an additional group of patients and trametinib as a treatment option for the severe associated phenotypes.

Ipilimumab induces simultaneous regression of melanocytic naevi and melanoma metastases.

Ipilimumab blocks cytotoxic T-lymphocyte-associated antigen (CTLA)-4, potentiating the antimelanoma T-cell host response. Ipilimumab has been shown to improve overall survival in patients with previously treated metastatic melanoma. CTLA-4 antibodies generate immune responses to the melanoma-associated antigens Melan-A, NY-ESO-1 and glycoprotein (gp)100 in metastatic melanoma. Digital epiluminescence microscopy (DELM) is a noninvasive method permitting the monitoring of the morphology of melanocytic lesions over time. A 50-year-old man with metastatic melanoma received four ipilimumab injections after failure of dacarbazine chemotherapy. Positron emission tomography revealed regression of pulmonary metastases, and simultaneously, DELM showed regression of several melanocytic naevi. On histological examination of the regressing naevi, prominent CD8+, CD4+ and CD45R0 lichenoid lymphohistiocytic infiltrates were seen, whereas nonregressing naevi were almost free of inflammatory infiltrate. Expression of melanoma-associated antigens in benign melanocytic naevi may explain the induction of naevus regression by ipilimumab. DELM could represent a valuable noninvasive method to monitor ipilimumab efficacy.

Photodynamic therapy for symptomatic subretinal fluid related to choroidal nevus.

PURPOSE: The purpose of this article is to evaluate the role of photodynamic therapy (PDT) for symptomatic choroidal nevus with subretinal fluid (SRF) extending to the fovea. METHODS: Retrospective review of the medical records of all patients who underwent PDT for a symptomatic choroidal nevus with SRF. RESULTS: Seventeen patients were included in the study. The mean initial visual acuity was 20/80 (range, counting fingers to 20/20). The mean initial tumor thickness was 1.23 mm (range, 0.66-1.93 mm). All tumors presented at least 2 risk factors for growing (including orange pigment, symptoms, peripapillary location, SRF, and thickness >2 mm). The mean number of PDT sessions was 1.41 (range, 1-3). The mean final visual acuity improved to 20/60 (range, counting fingers to 20/20). Subretinal fluid was reduced in all eyes (100%) and had completely disappeared in 9 eyes (53%) after PDT. Of 9 cases with complete resolution of the SRF, 2 patients (22%) presented recurrence. The mean final tumor thickness increased to 1.24 mm (range, 0.66-2.01 mm) at a mean follow-up of 22.47 months (range, 6-60 months). Tumor thickness increased in 3 eyes (18%) and remained unchanged in 13 eyes (76%), and 1 lesion (6%) shrank down to a flat chorioretinal scar. CONCLUSION: Photodynamic therapy is a good treatment option to reduce SRF in symptomatic choroidal nevus with serous macular detachment. Further growth into melanoma was observed in 18% of cases. Thus, PDT may not allow a good local tumor control. Longer follow-up is required to determine its value in these patients.

[Dermoscopic changes in melanocytic nevi during use of melanotan II]. / Dermatoskopische Veränderungen von melanozytären Nävi unter Verwendung von Melanotan II.

For cosmetic reasons, a 24-year-old man performed subcutaneous autoinjections with a preparation having alpha-MSH-like effects (melanotan II) purchased via the internet. The changes of patient's nevi were documented by sequential videodermoscopy before and during treatment. The observed dermoscopic changes made it difficult to differentiate a nevus from a melanoma.

A Randomized Double-blind Placebo-controlled Trial of Oral Aspirin for Protection of Melanocytic Nevi Against UV-induced DNA Damage.

DNA damage plays a role in ultraviolet (UV)-induced melanoma. We previously showed that aspirin (ASA) can suppress prostaglandin-E2 (PGE2) and protect melanocytes from UV-induced DNA damage in mice, and suggested that taking ASA before acute sun exposure may reduce melanoma risk. We conducted a prospective randomized placebo-controlled trial to determine if orally administered ASA could suppress PGE2 in plasma and nevi and protect nevi from UV-induced DNA damage. After obtaining plasma and determining the minimal erythemal dose (MED) in 95 subjects at increased risk for melanoma, they were randomized to receive a daily dose of placebo, 81 mg ASA, or 325 mg ASA, in double-blind fashion for one month. After this intervention, one nevus was irradiated (dose = 1 or 2 MED) using a solar simulator. One day later, MED was re-determined, a second plasma sample was obtained, and the UV-irradiated nevus and an unirradiated nevus were removed. ASA metabolites were detected in the second plasma sample in subjects in the ASA arms. There were no significant differences in the pre- and post-intervention MED between those patients receiving ASA and placebo. Significantly reduced PGE2 levels were detected in plasma (second vs. first samples) and in nevi (both unirradiated and UV-treated) in subjects receiving ASA compared to placebo. Comparing UV-treated nevi from the ASA and placebo cohorts, however, did not reveal significant reductions in CD3-cell infiltration or 8-oxoguanine and cyclobutane pyrimidine dimers. Thus ASA did not effectively protect nevi from solar-simulated UV-induced inflammation and DNA damage under the conditions examined. PREVENTION RELEVANCE: Despite promising rationale, ASA at conventional dosing was not able to protect nevi against UV-induced DNA damage under the conditions examined.See related Spotlight, p. 71.

Eruptive melanocytic naevi following initiation of elexacaftor/ivacaftor/tezacaftor for cystic fibrosis.

A 29 year old woman with cystic fibrosis (CF) presented to CF clinic following the sudden development of over 200 pigmented naevi located predominately on the trunk and limbs 3 months after commencing elexacaftor/tezacaftor/ivacaftor, a novel triple-therapy CFTR modulator therapy for CF. Skin biopsy confirmed benign naevi and the clinical presentation was consistent with eruptive melanocytic naevi. Elexacaftor/tezacaftor/ivacaftor received marketing authorisation in August 2020 and this is the first report of associated naevi. The individual described here remains clinically well, and continues on elexacaftor/tezacaftor/ivacaftor with dermatology follow-up.