Recently, the use of ultraviolet phototherapy has been increasing due to the development of new simple therapeutic light sources. It is important to understand the characteristics of such therapeutic machines and the basic principles of ultraviolet radiation. After the skin is exposed to ultraviolet radiation, reflection, scattering, and absorption occur at various levels of the skin, which is composed of numerous molecules, cells, and tissues. Longer wavelengths penetrate deeper than shorter wavelengths. Various photobiological reactions, such as those associated with phototherapy, are induced by photochemical reactions. Photochemical reactions can only be initiated by photons that have been absorbed by chromophores. The exposure dose, rather than the intensity (irradiance) or exposure time, is responsible for the photobiological response (reciprocity law). The therapeutic effects of ultraviolet radiation are derived from both direct and indirect processes. Both whole-body and targeted exposure have therapeutic advantages and disadvantages.Skin Research, 15: 1-7, 2016

View full abstract

A 62-year-old female presented with a palpable mass in her left axilla, which had been present for two months, in September 2014. Contrast-enhanced computed tomography revealed subcutaneous tumors and lymphadenopathy in her left neck, axilla, and scapular region. A needle biopsy of the affected lymph node demonstrated atypical proliferating tumor cells, which were positive for S100 and HMB45. The tumor was too large and had infiltrated too deeply to allow a radical resection to be performed. After the patient had been diagnosed with malignant melanoma, we conducted a mass-reducing operation and combination chemotherapy with dacarbazine and interferon-β. As these were not effective, we started performing chemotherapy with nivolumab. After the administration of two doses of nivolumab, the tumor continued to grow rapidly. As vemurafenib received MHLW (Ministry of Health, Labour and Welfare) approval as a treatment for late-stage melanoma in February 2015, we replaced the nivolumab with vemurafenib. By 4 weeks after the start of vemurafenib therapy, the patient's tumor and lymph node metastases had markedly improved, and her pleural effusion had disappeared. Although the primary and metastatic tumor regrew 3 months later, and the patient died 6 months later, vemurafenib is an effective treatment for aggressive metastatic melanomas carrying BRAF gene mutations.Skin Research, 15: 8-11, 2016

View full abstract

An 84-year-old male had noticed asymptomatic skin-colored nodules on his upper back and upper bilateral extremities, which had appeared at the age of 71. The nodules had gradually increased in number, but not in size. Histologically, the lesion exhibited encapsulated nodules consisting of interlacing fascicles of nerve bundles. The spindle-shaped cells were S-100 protein-positive, and Bodian stain-positive axons were scattered within the nodules. The capsules were partially positive for epithelial membrane antigen, which was indicative of perineural differentiation. Traumatic neuroma was ruled out based on the patient's lack of relevant history, and palisaded encapsulated neuroma was excluded based on the patient's clinical and histopathological features. Although the patient's clinical and histological findings corresponded to mucocutaneous neuroma, his clinical course and medical history did not include any signs of congenital abnormalities or endocrine disease. We diagnosed the nodules as multiple cutaneous neuromas rather than idiopathic mucocutaneous neuromas because we did not detect any mucous lesions in this case.Skin Research, 15: 12-16, 2016

View full abstract

Case 1: An 88-year-old Japanese man presented with a pinkish plaque located on the anterior of the right auricle, which had been present for a month. Case 2: An 87-year-old Japanese woman presented with a pinkish-reddish nodule located on her left cheek, which had been present for 2 months. After a biopsy examination, the patients were diagnosed with Merkel cell carcinoma (MCC), and no remote metastases were found in either case. Neither the patients nor their families would consent to surgical treatment; therefore, we decided to perform radiation monotherapy. The tumors responded to the radiotherapy and gradually disappeared. More than 16 months after the radiotherapy, no local recurrences or remote metastases were detected in either case. In the National Comprehensive Cancer Network Guidelines (2016), combination therapy involving radical resection, sentinel lymph node biopsy, and radiotherapy is recommended for stage I or II MCC. However, in cases involving elderly patients or patients that refuse to undergo surgery, radiation monotherapy should be taken into consideration as a treatment option for stage I or II MCC patients. Future clinical studies based on the further accumulation of cases should examine the optimal treatment for elderly patients with MCC.Skin Research, 15: 17-22, 2016

View full abstract