F026. Dermatopathology Case Challenge: Recognizing Mimics and Masqueraders

Dr. Dirk Elston, professor and chair at the Medical University of South Carolina, presents a case study on dermatopathology, focusing on various fungal infections and their mimics. He begins with a patient experiencing necrotic lesions on the scalp, emphasizing the importance of distinct histological features for accurate identification of angiotropic fungi such as Mucor, black molds, Aspergillus, and Fusarium. These fungi are notable for their ability to invade blood vessels, leading to severe tissue necrosis and rapid patient decline if not quickly diagnosed. The discussion highlights critical differentiating traits: Mucor displays hollow, red hyphae, black molds exhibit thick blue walls and chlamydospores, while Aspergillus has delicate walls with goblet-like cytoplasm, and Fusarium combines traits of both black molds and Aspergillus. Dr. Elston stresses the urgency in treatment as antifungal efficacy varies by organism type. Additionally, he covers cutaneous plasmacytosis, a rising condition that mimics lymphoma but shows polytypic plasma cell populations. This condition has been spreading geographically and poses diagnostic challenges due to its refractory nature. Overall, the talk underscores the intricacies of dermatopathology in distinguishing between fungal diseases and their mimicked conditions to ensure effective treatment.