Symbiotic collision tumour of the scalp: squamous cell carcinoma and malignant melanoma.

Cutaneous collision tumours are the co-existence of two tumours of different histopathological morphologies that coincide at the same or adjacent anatomical sites. A large scalp nodule excised from a 70 year-old man revealed a collision tumour composed of cells of squamous carcinoma (SCC) and malignant melanoma. Immunohistochemistry using dual staining for melanoma and squamous cell carcinoma demonstrated an unusual pattern; nests of melanoma cells surrounded by a layer of squamous carcinoma cells. The unique architecture observed in the case suggested a relationship between the two tumours.

Anti-PD-1-induced high-grade hepatitis associated with corticosteroid-resistant T cells: a case report.

Effective treatment or prevention of immune side effects associated with checkpoint inhibitor therapy of cancer is an important goal in this new era of immunotherapy. Hepatitis due to immunotherapy with antibodies against PD-1 is uncommon and generally of low severity. We present an unusually severe case arising in a melanoma patient after more than 6 months uncomplicated treatment with anti-PD-1 in an adjuvant setting. The hepatitis rapidly developed resistance to high-dose steroids, requiring anti-thymocyte globulin (ATG) to achieve control. Mass cytometry allowed comprehensive phenotyping of circulating lymphocytes and revealed that CD4+ T cells were profoundly depleted by ATG, while CD8+ T cells, B cells, NK cells and monocytes were relatively spared. Multiple abnormalities in CD4+ T cell phenotype were stably present in the patient before disease onset. These included a population of CCR4-CCR6- effector/memory CD4+ T cells expressing intermediate levels of the Th1-related chemokine receptor CXCR3 and abnormally high multi-drug resistance type 1 transporter (MDR1) activity as assessed by a rhodamine 123 excretion assay. Expression of MDR1 has been implicated in steroid resistance and may have contributed to the severity and lack of a sustained steroid response in this patient. The number of CD4+ rhodamine 123-excreting cells was reduced > 3.5-fold after steroid and ATG treatment. This case illustrates the need to consider this form of steroid resistance in patients failing treatment with corticosteroids. It also highlights the need for both better identification of patients at risk and the development of treatments that involve more specific immune suppression.

Spontaneous improvement in late rectal mucosal changes after radiotherapy for prostate cancer.

PURPOSE: To describe the natural history of mucosal changes, in particular the development of telangiectases in the rectum, after radiotherapy (RT) for prostate cancer. METHODS AND MATERIALS: Twenty patients undergoing local-field, nonconformal RT for prostate cancer underwent flexible sigmoidoscopy every 6 months for up to 3 years after RT completion. Telangiectasis was scored as absent, single, multiple, or multiple confluent. The site and circumferential extent were also documented. The patients filled in a diary to document the symptoms they were experiencing, including rectal bleeding. RESULTS: Of the 20 patients, 12 developed multiple telangiectases, and 10 of these had rectal bleeding, which in all cases was mild. Telangiectasis was most commonly seen between 4 (anorectal junction) and 8 cm from the anal verge. In 5 patients, 4 of whom had multiple telangiectases, spontaneous resolution occurred. CONCLUSION: Late radiation effects in the rectum do not appear to be permanent in all cases. This first prospective prolonged evaluation may provide an explanation for the observation that rectal bleeding resolves in a large proportion of patients with mild symptoms after RT. The reasons for improvement in the late radiation changes in the rectum compared with the permanent changes seen in organs such as the skin are unknown.