Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 51 5 2013 05 15 329 333 EN Seyed Zahra Ghodsi Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. Pari Rahimi Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. Amir Ehsani Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. Pedram Noormohammadpour Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. Masood Asgrai Ackerman Academy of Dermatopathology, New York City, USA. Fatemeh Gholamali Department of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran. 2015 10 11 The study was undertaken to answer the question that how many patients with pigmentation of back and arms actually have amyloid deposits in pathology. 44 patients presenting with diffuse pigmentation of back and arms (DPOBA) were selected. Skin biopsies were performed in all cases from the affected sites. On all formalin fixed and paraffin embedded specimens, the following histochemical stains were performed: Haematoxylin and eosin (H&E), Congo red and immunohistochemical staining using anti-cytokeratin monoclonal antibody. In 9 of 44 cases (20%), amyloid deposits were found. In the remaining 35 cases (80%), H&E, Congo red and immunohistochemical staining failed to show any amyloid deposition. We were unable to find amyloid deposition in most of the patients presented with DPOBA. It seems that the signs may be attributable other disorders with similar clinical but different pathophysiologic aspects. https://acta.tums.ac.ir/index.php/acta/article/view/4437 https://acta.tums.ac.ir/index.php/acta/article/download/4437/4597