TY - JOUR T1 - Case for diagnosis. Radiotherapy-induced pemphigus vegetans JO - Anais Brasileiros de Dermatologia T2 - AU - Almeida Jr,Hiram Larangeira de AU - Almeida,Antônia Larangeira de AU - Martinez,Pedro Henrique Evangelista AU - Boff,Ana Letícia SN - 03650596 M3 - 10.1016/j.abd.2021.09.005 DO - 10.1016/j.abd.2021.09.005 UR - http://www.anaisdedermatologia.org.br/en-case-for-diagnosis-radiotherapy-induced-pemphigus-articulo-S0365059622000435 AB - A 73-year-old male patient developed a poorly differentiated squamous cell carcinoma in the anal canal nine months ago. He was treated with two cycles of 5-fluorouracil and cisplatin and concomitant radiotherapy (6 MeV linear photon accelerator, total dose of 54 Gy), with complete remission. Since forty-five days he presentes a painful perianal and intergluteal erosion with circinate pustular borders. Light microscopy showed pseudoepitheliomatous hyperplasia of the epidermis with microabscesses of inflammatory cells (neutrophils and eosinophils) and acantholytic keratinocytes . Indirect immunofluorescence was positive for IgG, with an intercellular pattern, 1:80 titer. The diagnosis of radiotherapy-induced pemphigus vegetans was established and there was significant regression with oral prednisone (40 mg) and topical betamethasone. ER -