Original StudyHistopathology of Pemphigus Vulgaris RevisitedManocha, Anisha MD; Tirumalae, Rajalakshmi MD, DNB Author Information Department of Pathology, St. John's Medical College, Bangalore, India. Correspondence: Rajalakshmi Tirumalae, MD, DNB, Department of Pathology, 2nd Floor, St. John's Medical College, John Nagar, Bangalore, Karnataka 560 034, India (e-mail: [email protected]). The authors declare no conflicts of interest. The American Journal of Dermatopathology: June 2021 - Volume 43 - Issue 6 - p 429-437 doi: 10.1097/DAD.0000000000001838 Buy Metrics Abstract Pemphigus vulgaris (PV) is a severe, potentially life-threatening autoimmune blistering disease, which is common in India. Although there is abundant literature on clinical and immunologic features, comprehensive studies on its histopathology are lacking. The aim of this study was to describe the histopathologic and immunofluorescence features as well as discuss various diagnostic pitfalls of PV. Histopathologic and immunofluorescence (DIF/IIF) findings were reviewed for 169 biopsies from 2007 to 2017 (11 years). The 169 samples included 152 skin, 16 oral mucosal, and 1 corneal biopsy. Maximum prevalence was noted in the fifth decade (57%) with a slight male preponderance. Vesicles were seen in 149 cases (88%), the level of which was suprabasal in 91(61%) and both suprabasal and intraepidermal in 50 cases (33.5%). Acantholytic cells were present in 142 cases (95%). Acantholytic keratinocytes showed rounded and polygonal acantholysis. 86 (51%) cases showed evidence of regeneration. Adnexal involvement was seen in 92 cases, commonest in the hair follicles. Unusual histologic findings included: intraepidermal bulla, absence of dermal inflammation, free floating hair shafts, multinucleated epithelial cells, eosinophil predominance; all of which are discussed. DIF was performed in 166 cases, of which 163 were positive (98%), and IgG was the commonest immunoreactant (96%). IIF was performed in 11 cases, of which 9 cases were positive for Dsg3. Although the diagnosis of PV rests on combined clinical, histologic, and IF features, histopathology as the sole means is also a powerful tool. It is important to be aware of the diagnostic pitfalls to optimize its utility. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.