Cutaneous epithelioid hemangiomas show somatic mutations in the MAPK pathway

BACKGROUND

Epithelioid hemangioma (EH) arising from the skin is a benign vascular tumor with marked inflammatory cell infiltration, which exhibits a high tendency to persist and frequently recurs after resection. So far, the underlying pathogenesis is largely elusive.

OBJECTIVES

To identify genetic alterations by next-generation-sequencing and/or droplet digital PCR (ddPCR) in cutaneous EH.

METHODS

DNA and RNA from an EH lesion of an index patient were subjected to whole genome and RNA sequencing. Multiplex PCR-based panel sequencing of genomic DNA isolated from archival formalin-fixed paraffin-embedded (FFPE) tissue of 18 cutaneous EH patients was performed. ddPCR was used to confirm mutations.

RESULTS

We identified somatic mutations in genes of the MAPK pathway (MAP2K1 and KRAS) in cutaneous EH biopsies. By ddPCR we could confirm the recurrent presence of activating, low-frequency mutations affecting MAP2K1. In total, 9 out of 18 analyzed patients showed activating MAPK pathway mutations, which were mutually exclusive. Comparative analysis of tissue areas enriched for lymphatic infiltrate or aberrant endothelial cells, respectively, revealed an association of these mutations with the presence of endothelial cells.

CONCLUSIONS

Taken together, our data suggest that EH shows somatic mutations in genes of the MAPK pathway which might contribute to the formation of this benign tumor.

Neoadjuvant immunotherapy with combined ipilimumab and nivolumab in patients with melanoma with primary or in transit disease

The introduction of new therapeutic agents has revolutionized the treatment of metastatic melanoma. The approval of adjuvant anti-programmed death-1 monotherapy with nivolumab or pembrolizumab, and dabrafenib plus trametinib has recently set a new landmark in the treatment of stage III melanoma. Now, clinical trials have shown that immune checkpoint blockade can be performed in a neoadjuvant setting, an approach established as a standard therapeutic approach for other tumour entities such as breast cancer. Recent studies suggest that a pathological response achieved by neoadjuvant immunotherapy is associated with long-term tumour control and that short neoadjuvant application of checkpoint inhibitors may be superior to adjuvant therapy. Most recently, neoadjuvant ipilimumab plus nivolumab in stage III melanoma was reported. With two courses of dose-optimized ipilimumab (1 mg kg^-1 ) combined with nivolumab (3 mg kg^-1 ), pathological responses were observed in 77% of patients, while only 20% of patients experienced grade 3 or 4 adverse events. However, the neoadjuvant trials employing combined immune checkpoint blockade conducted so far have excluded patients with in transit metastases, a common finding in stage III melanoma. Here we report four patients with in transit metastases or an advanced primary tumour who have been treated with neoadjuvant ipilimumab plus nivolumab according to the OpACIN-neo trial scheme (arm B). All patients achieved radiological disease control and a pathological response. None of the patients has relapsed so far. Linked Comment: Blankenstein and van Akkooi. Br J Dermatol 2020; 183:421-422.

[Sarcoidosis : Dermatological view of a rare multisystem disease]

Sarcoidosis is a rare multisystem inflammatory disease of largely unknown etiology. While pulmonary sarcoidosis is the most abundant organ manifestation, involvement of the skin that occurs in up to 30% of patients is the most common extrapulmonary presentation of the disease. Dermatologists therefore play an important role not only for establishing the diagnosis and delineating it from potential differential diagnoses but also for the interdisciplinary care of the patient. The clinical presentation of skin sarcoidosis is manifold, which occasionally aggravates making the final diagnosis. Specific skin lesions (with granulomas) and nonspecific skin manifestations (without granulomas) can be differentiated. Since a variety of organ systems can be affected, multidisciplinary cooperation is mandatory. Therapy of sarcoidosis is difficult; evidence-based studies and therapy guidelines are widely lacking. Our review intends to outline the characteristic clinical presentations of cutaneous sarcoidosis, describe the diagnostic approach and how to assure or exclude extracutaneous manifestations of sarcoidosis, and suggest a therapy algorithm for the treatment of skin sarcoidosis.

Kutane Lymphome – ein vielgestaltiges Krankheitsbild

Kutane Lymphome präsentieren sich klinisch und histologisch oftmals ungewöhnlich und stellen nicht selten eine diagnostische Herausforderung für den Dermatologen dar. In dieser Arbeit werden die vielgestaltigen Präsentationsformen der Mycosis fungoides und anderer kutaner Lymphome anhand von Fallbeispielen aus der Würzburger Spezialsprechstunde für kutane Lymphome vorgestellt und ein Überblick über die Verwechslungsmöglichkeiten mit anderen Dermatosen gegeben.

[Differential diagnose of angioedema. Acute edematous scleromyxedema]

A woman presented in the emergency room with the diagnosis of angioedema refractory to treatment. She had soft, compressible periorbital edema, as well as edema of her hands and lower arms. She also complained of severe pain in her hands including sensations of numbness and tingling. The history, course and examination results eliminated several possible differential diagnostic considerations like an acute histamine- or bradykinin-mediated angioedema or superior vena cava syndrome. Histological examination confirmed the diagnosis of scleromyxedema.

[Dithiols as chelators. A cause of bullous skin reactions]

Chelation therapy with (RS)-2,3-Bis(sulfonyl)propane-1-sulfonic acid (DMPS) after an occupational lead exposure led to the development of a severe bullous drug eruption. Skin tests and histology/immunohistology of the test reactions indicated a T-cell-mediated immune response against DMPS. Metal-binding thiol groups as in DMPS are chemically highly reactive and therefore effectively mediate the development of immunogenic hapten (DMPS)-protein complexes. Therefore, the pharmacological effects and sensitization potential of dithiols are tightly connected. Cross-reactivity of DMPS to other chelators like D-penicillamine is possible; the indications for chelation therapy should be weighed carefully.

Central HER2 IHC and FISH analysis in a trastuzumab (Herceptin) phase II monotherapy study: assessment of test sensitivity and impact of chromosome 17 polysomy

AIMS

To investigate the correlation between centrally assessed human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) and fluorescence in situ hybridisation (FISH) results and response to treatment of patients with metastatic breast cancer enrolled in a first-line, phase II, open-label, 3-weekly trastuzumab (Herceptin) monotherapy trial (WO16229).

METHODS

Samples from participants in the WO16229 trial were collected and tumour HER2 status determined by IHC and FISH. HER2 test results were interpreted according to manufacturers' test kit protocols. Responders were defined as patients showing either partial or complete responses.

RESULTS

Response data were available for 103/105 patients; centrally confirmed HER2 status was available for 95 patients. Intra-laboratory concordance for central IHC and FISH results was 93%. Complete responses were seen in two patients; their samples were IHC 3+ and FISH positive. Partial responses were seen in 17 patients; all were IHC 3+ and 14 were FISH positive. IHC and FISH showed 100% and 84.2% sensitivity, respectively, in determining response to trastuzumab. Polysomy was observed in 27% of patients; six responded to trastuzumab treatment. All six responders showed HER2 overexpression (IHC 3+) and HER2 gene amplification; two were FISH negative due to chromosome 17 polysomy.

CONCLUSIONS

HER2 determination by IHC and FISH correlates with clinical response data in the WO16229 trial with high concordance of IHC and FISH results. Polysomy is the major cause of response in FISH-negative cases; polysomic cases should be retested by strictly standardised IHC.

Positive display of methylated sites: a novel method for the detection of promoter methylation

Promoter methylation represents an important mechanism for silencing gene expression in higher eukaryotes. To study methylation of the promoter of the tumor suppressor p16INK4a, a fast and simple method was developed that, in contrast to previous studies, relies on the positive display of methylated sites (PDM). The method is based on bisulfite treatment of DNA, polymerase chain reaction (PCR)-amplification of the modified DNA and restriction digest of de novo created restriction sites to positively display DNA methylation in a background of unmethylated DNA. Since methylated as well as unmethylated DNA is amplified, information on the proportion of both is provided. Using this approach, 33 ductal invasive carcinomas, 4 normal mammary tissues, and 4 cell lines were analyzed for methylation. Methylation in the p16INK4a promoter was detected in 1 of 33 carcinomas (3%) and in 0 of 4 normal tissues. The conclusion is that PDM provides a useful tool in determining the degree and pattern of promoter methylation and is suitable to screen large series of tissue samples.