Radiation-induced cutaneous squamous cell carcinoma showing a significant response to pembrolizumab: A case report.

Cutaneous squamous cell carcinoma (cSCC) arising from radiation dermatitis has a higher risk of metastasis than conventional cSCC. Immunosuppression is another risk factor for cSCC, suggesting that mycosis fungoides (MF) could be a risk factor for cSCC. Here we report a case of radiation-induced cSCC with a high level of tumor-mutation burden that developed in a patient with MF who was successfully treated with pembrolizumab. The present case suggests that pembrolizumab might be an optimal therapy for radiation-induced cSCC, even at advanced stages.

Gastrointestinal polyposis with esophageal polyposis is useful for early diagnosis of Cowden's disease.

Cowden's disease, one of the several hamartoma syndromes, is characterized by hyperplastic lesions and hamartomas distributed in the whole body. About thirty percent of patients with Cowden's disease have been reported to be complicated by malignant tumors. Based on the criteria of the International Cowden Consortium, this disease is mainly diagnosed as trichilemmoma of the face and oral mucosal papillomatosis. However, Cowden's disease patients themselves often do not recognize trichilemmoma of the face and oral mucosal papillomatosis. We report a case of Cowden's disease in a 33-year-old female patient who was diagnosed based on the characteristic findings at gastrointestinal endoscopy. Clinically, the patient was aware of having bloody stools. Multiple polyps found endoscopically in the esophagus, stomach, ileum, colon and rectum showed histopathologically hamartomatous changes and epithelial hyperplasia. Physical examination revealed oral papillomatosis and facial trichilemmomas. A germline mutation in exon 8 of the phosphatase and tensin homolog deleted on chromosome ten (PTEN) gene was found in this case. It was a point mutation of C to T at codon 1003 (CGA-->TGA, arginine-->stop codon). The characteristic findings on gastrointestinal endoscopy led us to a diagnosis of Cowden's disease. It has been reported that gastrointestinal polyposis with esophageal polyposis is found in about 85.7% of Japanese patients with Cowden's disease. The characteristic findings on gastrointestinal endoscopy can be a useful diagnostic clue to Cowden's disease.

CCR4 Expression by atypical T cells in systemic pilotropic lymphoma: its behavior under treatment with interferon gamma, topical PUVA and systemic retinoid.

We describe an 88-year-old Japanese patient with pilotropic T cell lymphoma involving the peripheral blood as well as lymph nodes. This patient presented with multiple red follicular papules, confluent, infiltrated erythematous plaques and nodules. Moreover, he was conspicuous for the presence of total alopecia of the scalp and eyebrows. Histopathologically, the lesional skin showed dense follicular and perifollicular infiltrates of atypical lymphocytes. The flow cytometry disclosed the presence of weakly CD4+ CCR4+ cell populations that would not be detected in the peripheral blood from healthy controls. The patient responded well to topical PUVA and systemic etretinate (retinoid-PUVA) and intravenous IFN-gamma. Parallel with the decrease in atypical cells in the peripheral blood, the percentage of weakly CD4+ CCR4+ T cells declined. However, about 1 week after we discontinued this treatment because of the side effects, the lymph node swelling became prominent, and, 4 weeks later, the patient died before restarting any specific chemotherapy.