Not Follicular but Dermal Melanocyte Precursors Are Histopathologically Retained in Vitiligo

Although perifollicular repigmentation in the vitiligo lesions is owing to activation of follicular melanocyte stem cells and/or precursor cells followed by supplying matured melanocytes, the underlying mechanism of diffuse repigmentation on the whole vitiligo surface remains still unknown. In addition to the presence of remaining melanocytes, it is conceivable that dermal melanocyte precursor cells contribute to induce diffuse repigmentation after treatment. Therefore, we investigated here whether dermal and follicular melanocyte precursor cells were reduced or not in vitiligo lesions. We performed an immunostaining for Nestin and p75NGFR as dermal melanocyte precursor cells and MITF/Fzd4 as follicular melanocyte precursor cells and compared the positive cells number between lesions and non-lesions (n = 11). Although MITF+/Fzd4+ cells in the hair follicle were significantly decreased in number in the lesions, Nestin+ and p75NGFR+ cells were not. This result indicates that dermal precursor cells could be retained in the vitiligo lesions but be disturbed to differentiate into matured melanocytes.

Non-Invasive Evaluation and Differential Diagnosis for Pediatric Leukoderma in a Single Institute

Background: Although vitiligo shows a similar clinical picture to other disorders in which patients exhibit depigmented spots, there are few reports on the differentiation of these conditions from each other. Purpose: We aimed to investigate the differences and similarities between vitiligo and nevus depigmentosus in children based on the clinical course and characteristics. Materials and Methods: We conducted an examination of the disease type, treatment, progress, and differentiation of 85 cases of vitiligo and nevus depigmentosus that developed before 15 years of age among patients who visited the Osaka University Department of Dermatology with a chief complaint of white patches from January 2010 to March 2017. Results: The median age at the onset of symptoms of 79 patients with vitiligo was 4.5 years and while that of 6 patients with nevus depigmentosus was 0.8 years, indicating that the onset of nevus depigmentosus occurred earlier. While vitiligo often developed in the head and neck regions, with a tendency for depigmented spots in multiple regions, nevus depigmentosus did not show this tendency in these regions. Upon performing Wood’s lamp observation in 38 cases of vitiligo, 35 cases were found to be fluorescent chalky white and in 3 cases histologically diagnosed as vitiligo, no clear fluorescent color was observed. All 6 patients diagnosed with nevus depigmentosus exhibited a non-fluorescent off-white color under a Wood’s lamp. Conclusions: This study indicates that non-invasive observation using a Wood’s lamp is useful in the differential diagnosis of pediatric leukoderma, in addition to the subsequent clinical course, such as the presence or absence of lesional repigmentation and/or enlargement.

A Rare Case of Small Bowel Intussusception Due to Metastatic Malignant Melanoma

The small intestine is sometimes metastasized by malignant melanoma. While small intestinal involvement is asymptomatic or usually nonspecific, intussusception causing intestinal obstruction is very rare. Herein we report the case of a 68-year-old man with small bowel intussusception due to metastatic malignant melanoma. Although he has been comprehensively treated with surgery, radiation, and immunotherapies, the disease rapidly progressed and consequently severe life-threatening intussusception developed on the small bowel. Because surgical resection of the obstructive melanoma lesions was successful, his quality of life was dramatically improved followed by the resumption of treatment with anti-PD-1. Several effective treatments for metastatic melanoma, including immune checkpoint inhibitors and targeted therapy, have been developed within the past decade. However, given the present case, surgical approaches to symptomatic metastatic melanoma lesions should still be considered as a treatment option for improving not only patients’ critical condition but also their survival.

Successful Treatment of Intra-Arterial Peplomycin Infusion for Recurrent Oral Florid Papillomatosis

A 56-year-old woman had noticed the erosion of oral mucosa and tongue 8 years ago. The mucosal lesions had been initially diagnosed as oral lichen planus and resistant to various treatments with prednisolone, etretinate and mizoribine and so on. One year ago, rapidly growing verrucous lesion occurred on her upper lip. Although we administered intralesional radiation therapy, the tumor recurred and new whitish lesions on the buccal mucosa and hard palate occurred 9 months after treatment. We confirmed an anatomical blood supply to the tumors by a fluorescent real-time imaging system and subsequently administered the intra-arterial infusion of peplomycin through retrograde catheters from bilateral superficial temporal arteries under the final diagnosis as oral florid papillomatosis (OFP). The tumors were dramatically shrunk and did not recur 16 months after treatment. OFP is known as clinically multiple whitish and verrucous lesions over the oral cavity and lip and a subtype of SCC with high differentiation. We suppose that an intra-arterial infusion therapy of peplomycin should be considered as the curative treatment for OFP.

Clinical Observation and Proposed Classification of Vitiliginous Patches by a Wood’s Lamp

Although vitiligo lesion especially in static state is characterized as sharply demarcated and complete depigmented macule, we encounter patients who have various manners of hypopigmented lesions. We examined the 81 lesions using the newly released Wood’s lamp (Woody®) and investigated whether or not vitiliginous lesions could be uniformly classified under Wood’s lamp illumination and also this classification helped to estimate the tendency of repigmentation after treatment. As result, the vitiliginous lesions were categorized into 4 types on intra- and peri-lesions prior to treatment by using the Wood’s lamp. The inside and border of the lesions were classified as follows: clear white, faint, multi-dot, and perifollicular for the inside, and sharp, blunt, confetti, and trichrome for the border. Suggestive residual pigmentation was detected in 73.6% of patients at the first visit and repigmentation was observed in 67.9% of patients at least 3 months after treatment. Lesions with the “clear white” inside pattern showed significantly lower repigmentation frequency in 38.5% of patients compared to others. The borders with 4 enlarged lesions were composed of 3 of confetti-type and one of sharp-type. This preliminary study demonstrated that detailed observation with a Wood’s lamp could be the basis to classify vitiliginous lesions and might be useful for predicting not only disease progression but also repigmentation prior to treatment.

Asian Case of Metastatic Melanoma in Which a Complete Response Was Maintained after Discontinuation of Dabrafenib and Trametinib

A 54-year-old man diagnosed with metastatic melanoma of the right inguinal node with occult primary developed liver and bone metastases. The combination of dabrafenib plus trametinib was initiated, and a complete response (CR) was achieved 24 months after starting treatment. One month later, the target therapy was discontinued at the patient’s decision, and he has remained free from progression for 21 months since discontinuation. To the extent of our knowledge, real-world data in Asian melanoma concerning the discontinuation of dabrafenib plus trametinib after achieving CR have not been published;therefore, our case is a meaningful one for considering to cease target drugs and to rescue their financial toxicity.