Polypoid Malignant Melanoma with Spontaneous Decapitation Showing Favorable Prognosis: A Case Report.

Introduction: Regression of malignant melanoma (MM) is a commonly observed phenomenon, which refers to disappearance or loss of all or part of MM. It can be identified both clinically and histologically, and high probability of histological regression of MM (10-58%) has been reported. However, the decapitation of skin tumor has rarely been described in the English literature, and decapitation in MM has not been reported. Here, we report the case of polypoid MM with spontaneous decapitation. Case Presentation: An 81-year-old Japanese woman was referred to our hospital due to a polypoid nodule on her cheek. She was diagnosed with MM at stage IIC (T4bN0M0) by histological examinations. Three weeks after the biopsy, the nodule decapitated spontaneously without bleeding, and an ulcer developed on the base of the polypoid nodule. The histological examination of the additionally resected ulcerative lesion under the nodule revealed infiltration of T cells mainly composed of CD8⁺ natural killer T cells. No recurrence or metastasis has been observed for 4 years. Conclusion: This is the first case report of polypoid MM with spontaneous decapitation, which may be attributed to natural killer T cells. Moreover, this case shows favorable prognosis, while it is said that the regression in thick MM does not have prognostic advantage and polypoid topography has been reported to be related to extremely poor prognosis. Further investigations are needed to evaluate the prognostic advantage of decapitation in MM and other skin tumors.

Analysis of IL-10 and IL-35 in dipeptidyl peptidase-4 inhibitor-related bullous pemphigoid.

The association between immunoregulatory cytokines, such as interleukin (IL)-10 or IL-35, and dipeptidyl peptidase-4 inhibitor (DPP4i)-related bullous pemphigoid (BP) has not been evaluated. Serum IL-10 and IL-35 levels were measured in 39 patients with BP (24 males and 15 females; 6 DPP4i-related and 33 DPP4i-unrelated BP patients) and 10 healthy controls. The number of CD26+ cells in the dermis around bulla on sections was counted immunohistochemically for 12 patients (six patients with DPP4i-related BP and six randomly sampled patients with DPP4i-unrelated BP). Patients with DPP4i-related BP had lower levels of serum eosinophils (DPP4i-related vs. DPP4i-unrelated BP: 476.1 ± 234.0 vs. 911.3 ± 948.8/µL; p = 0.537) and a higher rate of infiltrating CD26+ cells (32.9 ± 7.1% vs. 15.7 ± 4.4%; p = 0.01). There were no significant differences in serum IL-10 (6.77 ± 0.24 vs. 6.84 ± 0.20 pg/mL), serum IL-35 (2.63 ± 0.17 vs. 2.63 ± 0.21 pg/mL), serum anti-BP180NC16a antibodies (67.31 ± 37.4 vs. 76.18 ± 54.59 U/mL) and Bullous Pemphigoid Disease Area Index before treatment in this study. Serum IL-10 and IL-35 levels do not increase in patients with BP and may not be a candidate for a therapeutic target for BP. An increase in CD26+ cells might be associated with DPP4i-related BP.

Necrosis of Pedunculated Lipofibroma by Nab-Paclitaxel.

We present a rare phenomenon of a soft tumor hanging on the woman's left upper arm that underwent necrosis from the distal aspect during chemotherapy for pancreatic cancer. The benign tumor, pedunculated lipofibroma, originally had normal color for 10 years and then became necrotic when she was treated with gemcitabine and nab-paclitaxel. Necrosis stopped in conjunction with chemotherapy cessation. Dermatologists must remember that nab-paclitaxel could develop necrosis of a skin tumor.

Eosinophilic pustular folliculitis developing at the site of COVID-19 vaccination.

We present a rare case of eosinophilic pustular folliculitis due to mRNA-based vaccines for COVID-19. Histology of the biopsy specimen was very interesting.

Detection rate of pustules in palmoplantar pustulosis with dermoscopy.

In this study, dermoscopy was applied to determine the site of skin biopsy in cases of palmoplantar pustulosis (PPP) with invisible tiny pustules or vesicles. Fifty-two clinically diagnosed PPP patients (11 men and 41 women) were observed by a dermoscope and underwent skin biopsy. Nineteen patients had visible pustules, whereas 33 had no visible pustules. Pustules were detected by a dermoscope on palmoplantar lesions in 17 of the 33 PPP patients. In contrast, 16 patients showed no presence of pustules or vesicles observed by a dermoscope. In this group, biopsy specimens were taken from scaly lesions. Out of the 16 patients, 10 histologically showed pustules in the epidermis. We finally detected pustules for 46 patients among 52 who were clinically diagnosed with PPP. As a result, we detected pustules in PPP for 19 patients on "inspection", and 36 patients on "inspection and dermoscopy", and 46 patients on "inspection, dermoscopy, and biopsy". Dermoscopy is significantly useful comparing the detection rate (inspection, 0.41; inspection and dermoscopy, 0.78; p = 0.0003; using χ2 -test). In addition, we also should learn from the results that the detection rate goes down to 0.78 without a biopsy. Thus, dermoscopy is certainly a useful tool for invisible pustules and also undetectable pustules to detect pustules in PPP. Moreover, we objectively showed that "inspection, dermoscopy, and biopsy" are the best way to make a PPP diagnosis.