Extraordinary Case ReportUnilateral Periocular Intralymphatic Histiocytosis, Associated With Rosacea (Morbihan Disease)Belousova, Irena E. MD, PhD*; Kastnerova, Liubov MD†,‡; Khairutdinov, Vladislav R. MD, PhD*; Kazakov, Dmitry V. MD, PhD†,‡Author Information *Department of Dermatology, Medical Military Academy, Saint Petersburg, Russia; †Sikl's Department of Pathology, Medical Faculty in Pilsen, Charles University in Prague, Pilsen, Czech Republic; and ‡Bioptical Laboratory, Pilsen, Czech Republic. Correspondence: Dmitry V. Kazakov, MD, PhD, Sikl's Department of Pathology, Charles University Medical Faculty Hospital, Alej Svobody 80, 304 60 Pilsen, Czech Republic (e-mail: email@example.com). Supported in part by a Charles University project (SVV-2019 No. 260 391). The authors declare no conflicts of interest. Online date: November 19, 2019 The American Journal of Dermatopathology: June 2020 - Volume 42 - Issue 6 - p 452-454 doi: 10.1097/DAD.0000000000001567 Buy Metrics Abstract Intralymphatic histiocytosis is a rare reactive skin condition characterized by a nonspecific clinical presentation and, microscopically, by the collections of mononuclear histiocytes within the lumina of dilated lymphatic vessels. We report a rare case of intralymphatic histiocytosis associated with rosacea and prominent periocular edema (Morbihan disease). The patient is a 56-year-old woman with a 12-year history of rosacea who suddenly developed edema of the right upper eyelid that persisted 6 months before she sought medical advice. Because of an unclear clinical diagnosis, surgical excision of the edematous upper eyelid was performed. The histologic slides showed interstitial edema of the dermis with dilated vascular channels and small epithelioid cell granulomas around hair follicles. In addition, there were aggregates of cells inside numerous lymphatic vessels that were immunohistochemically positive for CD45, CD4, CD68, CD163, CD64, CD14, CD11c, and lysozyme and negative for CD3, CD20, CD30, CD56, S100, CD1a, and langerin. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.