A 20 MHz Repetition Rate, Sub-Picosecond Ti-Sapphire Laser for Fiber Delivery in Nonlinear Microscopy of the Skin.

Nonlinear microscopy (NM) enables us to investigate the morphology or monitor the physiological processes of the skin through the use of ultrafast lasers. Fiber (or fiber-coupled) lasers are of great interest because they can easily be combined with a handheld, scanning nonlinear microscope. This latter feature greatly increases the utility of NM for pre-clinical applications and in vivo tissue imaging. Here, we present a fiber-coupled, sub-ps Ti-sapphire laser system being optimized for in vivo, stain-free, 3D imaging of skin alterations with a low thermal load of the skin. The laser is pumped by a low-cost, 2.1 W, 532 nm pump laser and delivers 0.5-1 ps, high-peak-power pulses at a ~20 MHz repetition rate. The spectral bandwidth of the laser is below 2 nm, which results in a low sensitivity for dispersion during fiber delivery. The reduction in the peak intensity due to the increased pulse duration is compensated by the lower repetition rate of our laser. In our proof-of-concept imaging experiments, a ~1.8 m long, commercial hollow-core photonic bandgap fiber was used for fiber delivery. Fresh and frozen skin biopsies of different skin alterations (e.g., adult hemangioma, basal cell cancer) and an unaffected control were used for high-quality, two-photon excitation fluorescence microscopy (2PEF) and second-harmonic generation (SHG) z-stack (3D) imaging.

A Cross-Sectional Study of the Dermatological Manifestations of Patients with Fabry Disease and the Assessment of Angiokeratomas with Multimodal Imaging.

Fabry disease (FD) is a multisystemic X-linked lysosomal storage disease that presents with angiokeratomas (AKs). Our objective was to investigate the clinical and morphologic features of AKs and to present two experimental techniques, multispectral imaging (MSI) and non-linear microscopy (NLM). A thorough dermatological examination was carried out in our 26 FD patients and dermoscopic images (n = 136) were evaluated for specific structures. MSI was used for the evaluation of AKs in seven patients. NLM was carried out to obtain histology samples of two AKs and two hemangiomas. Although AKs were the most common manifestation, the majority of patients presented an atypical distribution and appearance, which could cause a diagnostic challenge. Dermoscopy revealed lacunae (65%) and dotted vessels (56%) as the most common structures, with a whitish veil present in only 25%. Autofluorescence (405 nm) and diffuse reflectance (526 nm) images showed the underlying vasculature more prominently compared to dermoscopy. Using NLM, AKs and hemangiomas could be distinguished based on morphologic features. The clinical heterogeneity of FD can result in a diagnostic delay. Although AKs are often the first sign of FD, their presentation is diverse. A thorough dermatological examination and the evaluation of other cutaneous signs are essential for the early diagnosis of FD.

Scrofuloderma and granuloma annulare-like lesions: Challenges of diagnosing cutaneous tuberculosis in developed countries.

Tuberculosis remains a global health concern, as the increasing levels of urban poverty, higher number of immunodeficient patients and the development of drug resistance threaten the overall efforts made to induce a downward trend for the disease. Scrofuloderma, also known as tuberculosis cutis colliquativa is a subtype of cutaneous tuberculosis. Here we detail a case of a 70-year-old female patient presented with unilateral, left-sided, multiple palpable, painful, ulcerated and purulent cervical nodules, accompanied by persistent generalized erythematous popular granuloma annulare-like skin lesions on the upper extremities. Based on the result of the PCR assay, culture, imaging and histopathological findings, the diagnosis of scrofuloderma was established. To achieve prompt diagnosis and early treatment, it is crucial to include scrofuloderma in the differential diagnosis of ulcerated lesions in developed countries as well, and also be aware of the additional clinical symptoms, such as granuloma annulare-like lesions, possibly accompanying cutaneous tuberculosis.

Emergency Use and Efficacy of an Asynchronous Teledermatology System as a Novel Tool for Early Diagnosis of Skin Cancer during the First Wave of COVID-19 Pandemic.

Background: After the outbreak of the corona virus disease-19 (COVID-19) pandemic, teledermatology was implemented in the Hungarian public healthcare system for the first time. Our objective was to assess aggregated diagnostic agreements and to determine the effectiveness of an asynchronous teledermatology system for skin cancer screening. Methods: This retrospective single-center study included cases submitted for teledermatology consultation during the first wave of the COVID-19 pandemic. Follow-up of the patients was performed to collect the results of any subsequent personal examination. Results: 749 patients with 779 lesions were involved. 15 malignant melanomas (9.9%), 78 basal cell carcinomas (51.3%), 21 squamous cell carcinomas (13.8%), 7 other malignancies (4.6%) and 31 actinic keratoses (20.4%) were confirmed. 87 malignancies were diagnosed in the high-urgency group (42.2%), 49 malignancies in the moderate-urgency group (21.6%) and 16 malignancies in the low-urgency group (4.6%) (p < 0.0001). Agreement of malignancies was substantial for primary (86.3%; κ = 0.647) and aggregated diagnoses (85.3%; κ = 0.644). Agreement of total lesions was also substantial for primary (81.2%; κ = 0.769) and aggregated diagnoses (87.9%; κ = 0.754). Conclusions: Our findings showed that asynchronous teledermatology using a mobile phone application served as an accurate skin cancer screening system during the first wave of the COVID-19 pandemic.

Quantitative Multispectral Imaging Differentiates Melanoma from Seborrheic Keratosis.

Melanoma is a melanocytic tumor that is responsible for the most skin cancer-related deaths. By contrast, seborrheic keratosis (SK) is a very common benign lesion with a clinical picture that may resemble melanoma. We used a multispectral imaging device to distinguish these two entities, with the use of autofluorescence imaging with 405 nm and diffuse reflectance imaging with 525 and 660 narrow-band LED illumination. We analyzed intensity descriptors of the acquired images. These included ratios of intensity values of different channels, standard deviation and minimum/maximum values of intensity of the lesions. The pattern of the lesions was also assessed with the use of particle analysis. We found significantly higher intensity values in SKs compared with melanoma, especially with the use of the autofluorescence channel. Moreover, we found a significantly higher number of particles with high fluorescence in SKs. We created a parameter, the SK index, using these values to differentiate melanoma from SK with a sensitivity of 91.9% and specificity of 57.0%. In conclusion, this imaging technique is potentially applicable to distinguish melanoma from SK based on the analysis of various quantitative parameters. For this application, multispectral imaging could be used as a screening tool by general physicians and non-experts in the everyday practice.

Efficiency of long-term high-dose intravenous ascorbic acid therapy in locally advanced basal cell carcinoma - a pilot study.

INTRODUCTION: The anti-cancer properties of high-dose intravenous ascorbic acid have been demonstrated in various malignancies. In our recent study, we tested topically applied ascorbic acid to treat basal cell carcinoma (BCC), and achieved a good clinical response. AIM: Based on these results, we decided to examine the efficacy and tolerability of high-dose intravenous ascorbic acid (IVA) for locally advanced BCC. MATERIAL AND METHODS: In this pilot study, patients diagnosed with locally advanced BCC who were not amenable to radiation, surgical or local therapy (no other treatment option was available at the time) received intravenous ascorbic acid (1-1.8 g/kg), in an outpatient setting, 1-3 times per week for a mean duration of 42 ±23.6 weeks. This therapy was generally well tolerated. RESULTS: Among 4 patients who had a total of 165 (mean: 41 ±51, range: 1-114) skin lesions, 3 patients achieved stable disease and one had progressive disease. There was substantial variability in individual tumor response to therapy. With the aid of two-photon microscopy and second harmonic generation imaging techniques, alterations in collagen structure were observed between tumor nests during IVA therapy. CONCLUSIONS: Our results suggest that IVA is well tolerated in a small group of patients with extensive BCCs. However, in the era of smoothened (Smo) receptor inhibitors, it may only be considered as an adjuvant therapy in treatment-resistant cases.

Smoothened receptor inhibitor vismodegib for the treatment of basal cell carcinoma: a retrospective analysis of efficacy and side effects.

Background: Smoothened receptor inhibitor vismodegib is indicated to treat locally advanced basal cell carcinoma (laBCC) and lesions in nevoid basal cell carcinoma syndrome (NBCCS).Methods: We treated 11 patients - including four NBCCS and seven laBCC patients - with vismodegib at our department.Results: Complete remission was achieved in three cases, without relapse after discontinuation. Two of the aforementioned patients had NBCCS, in their cases further treatment might be needed. Two patients showed improvement, but later passed away due to unrelated conditions. Two patients with laBCC initially showed remission, then the treatment was suspended due to side effects. After re-administration of the drug, loss of efficacy was observed. We did not observe therapy resistance in our NBCCS group. The rest of the patients showed good response to therapy, but have not reached full remission yet. The main side effects of vismodegib were muscle cramps, dysgeusia, nausea and alopecia. The frequency of adverse events did not show significant differences between the patient groups.Conclusions: Our results show that vismodegib therapy is effective in the treatment of BCC; however, side effects are often severe. Since the suspension of treatment can lead to therapy resistance, the management of side effects is of great importance.

Intralesional therapy for the treatment of keratoacanthoma.

Keratoacanthoma (KA) is a common epidermal tumor that originates from the hair follicle of the skin. It is generally considered as a benign neoplasm, but in rare cases, it can also transform into squamous cell carcinoma. Although surgical excision with a safety margin is considered to be the gold standard treatment for most subtypes of KA, several other treatment options are also available. Intralesional therapy is one of these options, which could be cosmetically and functionally a better alternative to surgical removal, while it provides similar outcomes. It is more effective than topical treatments, yet fewer side effects may be seen than in systemic treatments. Based on the literature, the most commonly used intralesional agent is methotrexate, followed by 5-fluorouracil and interferon alpha. Regardless of the advantages, which make intralesional therapy a desirable treatment alternative, guidelines for the intralesional treatment of KA are not yet established. A histopathological confirmation before the start of treatment is still recommended to prevent any possible misdiagnosis of KA for SCC. In our present study, we set out to review the current state of the art of the intralesional treatment of KA.