CME ArticleHistopathologic Spectrum of MorpheaChiu, Yvonne E. MD*; Abban, Cynthia Y. MD, PhD†; Konicke, Kathryn MD‡; Segura, Annette MD¶; Sokumbi, Olayemi MD§Author Information *Associate Professor, Departments of Dermatology and Pediatrics, Section of Pediatric Dermatology, Medical College of Wisconsin, Milwaukee, WI; †Staff Dermatologist, Aurora Healthcare, Gurnee, IL; ‡Dermatology Resident, Department of Dermatology, Medical College of Wisconsin, Milwaukee, WI; §Assistant Professor, Department of Pathology, Section of Pediatric Pathology, Medical College of Wisconsin, Milwaukee, WI and ¶Assistant Professor, Department of Dermatology, Medical College of Wisconsin, Milwaukee, WI. Correspondence: Yvonne E. Chiu, MD, Associate Professor, Department of Dermatology, 8701 Watertown Plank Road, Milwaukee, WI 53202 (e-mail: [email protected]). Y. E. Chiu received a Dermatology Foundation Career Development Award to support this research and is a past grant recipient of Novan, Inc. Lippincott CME Institute has identified and resolved all conflicts of interest concerning this educational activity. All remaining authors, faculty, and staff in a position to control the content of this CME activity and their spouses/life partners (if any) have disclosed that they have no financial relationships with, or financial interests in, any commercial organizations relevant to this educational activity. The American Journal of Dermatopathology: January 2021 - Volume 43 - Issue 1 - p 1-8 doi: 10.1097/DAD.0000000000001662 Buy CME Test Metrics Abstract Morphea is an autoimmune skin disease with protean clinical manifestations. Histologic features are similarly variable, and skin biopsies may be nondiagnostic. A single-institution retrospective cohort study was conducted. Morphea patients who had a biopsy in 2005–2015 were included, and a histopathological review was conducted by 2 pathologists. There were 51 biopsy specimens from 40 subjects. The most common histologic features were dermal sclerosis (90%), dermal thickening (78%), collagen homogenization (86%), a superficial and deep infiltrate (76%), a moderate–abundant inflammatory infiltrate (73%), and periadnexal fat loss/decreased skin appendages (71%). Twenty-four specimens were not diagnostic of morphea. In these specimens, the main clues to diagnosis included the presence of dermal sclerosis (79%), subtle collagen homogenization (75%), dermal thickening (58%), moderate-to-abundant plasma cells (50%), and perineural inflammation (50%). There were no statistically significant differences between active and inactive lesions, nor untreated and treated lesions. The histopathologic features of morphea are variable and a high proportion of biopsies are not diagnostic. Clinicians and pathologists should have a high degree of suspicion to correctly make the diagnosis of morphea. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.