Checkpoint immunotherapy of cutaneous squamous cell carcinoma in patients suffering from chronic lymphocytic leukaemia: divergent outcomes in two men treated with PD-1 inhibitors.

Cutaneous squamous cell carcinoma (cSCC) numbers among the most common types of skin cancer and is known as one of the cancer entities with the highest mutational burden among all solid tumours. Due to the positive correlation between mutational burden and response rate to inhibitors of the programmed cell death 1 (PD-1), those inhibitors are considered promising candidates for the systemic therapy of cSCC. Recently, the PD-1 inhibitors pembrolizumab, nivolumab and cemiplimab demonstrated efficacy in the systemic treatment of locally advanced or metastatic cSCC leading to the approval of cemiplimab by the FDA (U.S. Food and Drug Administration) in 2018 and the EMA (European Medicines Agency) in 2019. Patients with haematological malignancies tend to develop skin cancers of high aggressiveness, enhanced cumulative recurrence rate and higher rates of metastases with subsequent death. Chronic lymphocytic leukaemia (CLL) is the most frequent type of leukaemia in the United States and Europe with the majority of patients older than 50 years of age. This neoplasm predominantly originates from B -cells leading to an impaired immune system of the patient. Although CLL is a B-cell malignancy, studies have also described the involvement of T cells in the pathogenesis and progression of the disease with contradictory findings on the effects of PD-1 inhibitors in CLL. Due to their underlying hematologic malignancy, these patients have commonly no access to PD-1 inhibitor trials for treatment of advanced cSCC. We report on two patients with locally advanced or metastatic cSCC. Both patients had been suffering from a CLL for many years without indication for treatment. Despite a potential immunosuppressive state of the patients due to their CLL, both were treated with the PD-1 inhibitor pembrolizumab resulting in different therapy outcomes.

Management of partial and non-responding cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) and basal cell carcinoma are the most common types of skin cancer. For patients with locally advanced and metastatic cSCC, the programmed cell death 1 (PD-1) inhibitor cemiplimab is approved for systemic treatment. Despite this revolutionary immunomodulatory therapeutic approach, tumours may fail to respond either completely or partially. In addition to the previously established local treatment with radiotherapy or systemic treatment with chemotherapy and epidermal growth factor receptor inhibitors, ongoing trials are currently focussed on re-stimulating the antitumour immune response in patients with advanced cSCC refractory to PD-1 inhibitors. In this review, ongoing and recently finished trials with different therapeutic approaches will be discussed.

[Cutaneous angiosarcoma clinically presenting as Quincke's edema]. / Kutanes Angiosarkom mit klinischem Bild eines Quincke-Ödems.

We report a case of a 75-year-old man with facial edema that also affected the periorbital area who was admitted to the hospital with the suspected diagnosis of Quincke's edema. The diagnosis of cutaneous angiosarcoma was made by microscopic examination and immunohistochemical staining. Chemotherapy was initially initiated because the angiosarcoma was unresectable and the radiation situation was difficult. Therapy has to be switched to second and third line therapy due to disease progression. The case illustrates the complexity of diagnosis and therapy in patients with cutaneous angiosarcoma.

Eosinophilic pustular folliculitis (EPF) in a patient with HIV infection.

Eosinophilic pustular folliculitis is a chronic, recurrent dermatosis, of unknown etiology, which is histologically characterized by folliculotropic inflammatory infiltrates with admixed eosinophils in the dermis. It has often presented with immunosuppression and especially with HIV-Infection. In the HAART-era, eosinophilic pustular folliculitis has become a rarity. It is often being misdiagnosed as acne vulgaris, rosacea, bacterial folliculitis, dermatomycosis and seborrheic dermatitis. The treatment of this disease may be difficult.

GNAQ and GNA11 mutant nonuveal melanoma: a subtype distinct from both cutaneous and uveal melanoma.

BACKGROUND: GNAQ and GNA11 mutant nonuveal melanoma represent a poorly characterized rare subgroup of melanoma with a gene mutation profile similar to uveal melanoma. OBJECTIVES: To characterize these tumours in terms of clinical behaviour and genetic characteristics. METHODS: Patients with nonuveal GNAQ/11 mutated melanoma were identified from the prospective multicentre tumour tissue registry ADOREG, Tissue Registry in Melanoma (TRIM) and additional cooperating skin cancer centres. Extensive data on patient, tumour and treatment characteristics were collected retrospectively. Targeted sequencing was used to determine tumour mutational burden. Immunohistochemistry staining was performed for programmed death-ligand 1 and BRCA1-associated protein (BAP)1. Existing whole-exome cutaneous and uveal melanoma data were analysed for mutation type and burden. RESULTS: We identified 18 patients with metastatic GNAQ/11 mutant nonuveal melanoma. Tumours had a lower tumour mutational burden and fewer ultraviolet signature mutations than cutaneous melanomas. In addition to GNAQ and GNA11 mutations (nine each), six splicing factor 3b subunit 1 (SF3B1), three eukaryotic translation initiation factor 1A X-linked (EIF1AX) and four BAP1 mutations were detected. In contrast to uveal melanoma, GNAQ/11 mutant nonuveal melanomas frequently metastasized lymphatically and concurrent EIF1AX, SF3B1 and BAP1 mutations showed no apparent association with patient prognosis. Objective response to immunotherapy was poor with only one partial response observed in 10 treated patients (10%). CONCLUSIONS: Our findings suggest that GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is both clinically and genetically distinct from cutaneous and uveal melanoma. As they respond poorly to available treatment regimens, novel effective therapeutic approaches for affected patients are urgently needed. What is already known about this topic? The rare occurrence of GNAQ/11 mutations in nonuveal melanoma has been documented. GNAQ/11 mutant nonuveal melanomas also harbour genetic alterations in EIF1AX, SF3B1 and BAP1 that are of prognostic relevance in uveal melanoma. What does this study add? GNAQ/11 mutant nonuveal melanomas show metastatic spread reminiscent of cutaneous melanoma, but not uveal melanoma. GNAQ/11 mutant nonuveal melanomas have a low tumour mutational burden that is higher than uveal melanoma, but lower than cutaneous melanoma. What is the translational message? Primary GNAQ/11 mutant nonuveal melanomas are a subtype of melanoma that is clinically and genetically distinct from both cutaneous and uveal melanoma. As metastatic GNAQ/11 mutant nonuveal melanomas respond poorly to available systemic therapies, including immune checkpoint inhibition, novel therapeutic approaches for these tumours are urgently needed. Linked Comment: Rafei-Shamsabadi. Br J Dermatol 2020; 183:806-807.

NF1 mutations in conjunctival melanoma.

BACKGROUND: Conjunctival melanoma is a potentially deadly eye tumour. Despite effective local therapies, tumour recurrence and metastasis remain frequent. The genetics of conjunctival melanomas remain incompletely understood. METHODS: A large cohort of 63 conjunctival melanomas was screened for gene mutations known to be important in other melanoma subtypes by targeted next-generation sequencing. Mutation status was correlated with patient prognosis. RESULTS: Frequent mutations in genes activating the MAP kinase pathway were identified. NF1 mutations were most frequent (n = 21, 33%). Recurrent activating mutations were also identified in BRAF (n = 16, 25%) and RAS genes (n = 12, 19%; 11 NRAS and 1 KRAS). CONCLUSIONS: Similar to cutaneous melanomas, conjunctival melanomas can be grouped genetically into four groups: BRAF-mutated, RAS-mutated, NF1-mutated and triple wild-type melanomas. This genetic classification may be useful for assessment of therapeutic options for patients with metastatic conjunctival melanoma.

Altered density, composition and microanatomical distribution of infiltrating immune cells in cutaneous squamous cell carcinoma of organ transplant recipients.

BACKGROUND: The inflammatory tumour microenvironment is crucial for effective tumour control, and long-term immunosuppression has been identified as a major risk factor for skin carcinogenesis. In solid organ transplant recipients (OTRs) undergoing long-term pharmacological immunosuppression, an increased incidence of cutaneous squamous cell carcinoma (SCC) and more aggressive tumour growth compared with immunocompetent patients has been reported. OBJECTIVES: To determine the density and phenotype of immune cells infiltrating SCC and surrounding skin in OTRs, and to characterize the microanatomical distribution patterns in comparison with immunocompetent patients. METHODS: We analysed immune cell infiltrates within SCC and at defined regions of interest (ROIs) of tumour-surrounding skin in formalin-fixed paraffin-embedded tissue of 20 renal transplant patients and 18 carefully matched immunocompetent patients by high-resolution semiautomated microscopy on complete tissue sections stained for CD4, CD8, CD20 and CD68. RESULTS: The overall immune cell density of SCC arising in OTRs was significantly reduced compared with immunocompetent patients. Particularly CD4+ infiltrates at the directly invasive margin and tumour vicinity, intratumoral CD8+ T-cell densities and the overall density of CD20+ tumour-infiltrating B cells were significantly reduced in the tissue of OTRs. CONCLUSIONS: Immune cell infiltrates within SCC and at defined ROIs of tumour-surrounding skin in OTRs differ markedly in their composition and microanatomical distribution compared with tumours arising in immunocompetent patients. Our findings substantially broaden the understanding of how long-term systemic immunosuppression modulates the local inflammatory microenvironment in the skin and at the site of invasive SCC.

Dimethyl fumarate modulates neutrophil extracellular trap formation in a glutathione- and superoxide-dependent manner.

BACKGROUND: Neutrophil (polymorphonuclear) granulocytes (PMN) have been shown to contribute to the pathogenesis of psoriasis by releasing interleukin-17 and LL37-DNA complexes via neutrophil extracellular traps (NETs), webs of chromatin strands decorated with antimicrobial peptides, in psoriatic skin. Fumaderm® , a fumaric acid ester (FAE) formulation consisting of different FAE salts, has been successfully used to treat psoriasis for decades. Most recently, FAE treatment was reported to inhibit NET formation in murine epidermolysis bullosa acquisita. OBJECTIVES: To elucidate the effect of FAE treatment on human psoriasis and healthy donor NET formation. RESULTS: Among the compounds present in the FAE formulation, dimethyl fumarate (DMF) pretreatment of human psoriasis and healthy donor PMN resulted in a consistent inhibitory effect on NET formation in response to phorbol 12-myristate 13-acetate but not to platelet activating factor and ionomycin. This effect was l-glutathione (GSH) dependent and involved a decrease in reactive oxygen species (ROS) production, a key event in NET formation. In contrast, G-protein-coupled signalling and protein synthesis were not involved. Monomethyl fumarate (MMF) was found to slightly reduce ROS production without affecting NET formation. CONCLUSIONS: We report DMF as a potent, stimulus-specific, GSH- and ROS-dependent modulator of NET formation. Our results support the notion that modulation of NET formation contributes to the beneficial effects of FAEs in a variety of inflammatory conditions.

European Guidelines (S1) on the use of high-dose intravenous immunoglobulin in dermatology.

BACKGROUND: The treatment of severe dermatological autoimmune diseases and toxic epidermal necrolysis (TEN) with high-dose intravenous immunoglobulin (IVIg) is a well-established procedure in dermatology. As treatment with IVIg is usually considered for rare clinical entities or severe clinical cases, the use of immunoglobulin is not generally based on data from randomized controlled trials that are usually required for the practice of evidence-based medicine. Owing to the rarity of the indications for the use of IVIg, it is also unlikely that such studies will be available in the foreseeable future. Because the high costs of IVIg treatment also limit its first-line use, the first clinical guidelines on its use in dermatological conditions were established in 2008 and renewed in 2011. MATERIALS AND METHODS: The European guidelines presented here were prepared by a panel of experts nominated by the EDF and the EADV. The guidelines were developed to update the indications for treatment currently considered as effective and to summarize the evidence base for the use of IVIg in dermatological autoimmune diseases and TEN. RESULTS AND CONCLUSION: The current guidelines represent consensual expert opinions and definitions on the use of IVIg reflecting current published evidence and are intended to serve as a decision-making tool for the use of IVIg in dermatological diseases.

[Pruritic submammary papular lesions]. / Juckende Papeln submammär.

Focal, mostly suprabasal acantholyis with development of dyskeratotic keratinocytes are typical histological features of Grover's disease. The histological distinction between other forms of acantholytic dermatoses is often difficult. A combined assessment of the histological findings and the clinical symptoms often allows a clear diagnosis. The disease is self-limiting but treatment is necessary in some cases due to the sometimes excessive pruritis.