CASE REPORT Pathological and molecular detection of a rare case of cutaneous cryptococcosis in a 9-year-old horse Abdelmoneim Ali 1 & Bakr Ahmed 1 & Naif AlGabri 2 & Mohamed Abdelmoneim 3 & Mohamed Gomaa 4 & Ahmed N. F. Neamat-Allah 5 Received: 14 January 2020 /Accepted: 3 April 2020 # Springer-Verlag London Ltd., part of Springer Nature 2020 Abstract This report describes a rare case of primary cutaneous cryptococcosis in equines. A young gelding horse was presented with facial masses showing ulcerations and yellowish discharge. Histopathological examination of biopsy specimens showed a dermal granulomatous reaction containing neutrophils, macrophages, and giant cells. In addition, numerous spherical yeast-like organ- isms were clearly observed within the granulomatous reaction. We suspected that the observed organisms belong to the Cryptococcus spp., which was indeed by its shape on Sabouraud dextrose agar, Gram-stained smear suggestive C. neoformans, and confirmed on PCR. Our report is one of the worldwide rare reports linking cryptococcosis to cutaneous granuloma in equines and the first to provide a molecular confirmation of the cryptococcal involvement. The report highlights the importance of considering cryptococcosis in differential diagnosis of infectious cutaneous masses in equines. Keywords C. neoformans . Horse . PCR . Histopathology . Granuloma . Skin Introduction Many cutaneous diseases with varied causative pathogen af- fecting livestock (Ali et al. 1990; Neamat-Allah 2015; Neamat-Allah and Damaty 2016 ; Neamat-Allah and Mahmoud 2019). Cryptococcosis is a granulomatous mycotic disease of animals with worldwide prevalence (Cafarchia et al. 2013; Refai et al. 2017). The disease is caused by the Cryptococcus spp., which are encapsulated basidiomycetous yeasts inhabiting soil and plants contaminated with bird drop- pings. Within the cryptococcal genera, C. neoformans and C. gattii are most frequently associated with the disease (Perfect and Bicanic 2015; Sorrell 2001). Equine cryptococcosis commonly involves the respiratory or the nervous system. The most common disease form is rhinitis and nasal granuloma, which can extend to the lung to cause pneumonia or disseminate through the blood to the brain to cause meningitis and encephalitis (Cafarchia et al. 2013; Refai et al. 2017). The cutaneous form has been rarely reported, with only less than a handful of reports linking cryp- tococci to cutaneous fungal infections (Boulton and Williamson 1984; Chandna et al. 1993; Khodakaram-Tafti and Dehghani 2006). The present report describes the histo- pathological and molecular diagnosis of one of the rare cases of cutaneous cryptococcosis that was presented in a 9-year-old horse. Case presentation A 9-year-old gelding horse was presented to the hospital of the Faculty of Veterinary Medicine, Zagazig University, Egypt, for the examination of multiple cutaneous masses on the left * Abdelmoneim Ali Abdelmoneim.ahmedali@yahoo.com 1 Department of Pathology, Faculty of Veterinary Medicine, Zagazig University, Altajneed 11, Zagazig 44511, Egypt 2 Department of Veterinary Medicine, Faculty of Agriculture and Veterinary medicine, Thamar University, Sanaa-Taiz 8, 87246 Dhamar, Yemen 3 Department of Bacteriology, Mycology and Immunology, Faculty of Veterinary Medicine, Zagazig University, Altajneed 11, Zagazig 44511, Egypt 4 Department of Surgery, Anesthesiology and Radiology, Faculty of Veterinary Medicine, Zagazig University, Altajneed 11, Zagazig 44511, Egypt 5 Department of Clinical Pathology, Faculty of Veterinary Medicine, Zagazig University, Altajneed 11, Zagazig 44511, Egypt Comparative Clinical Pathology https://doi.org/10.1007/s00580-020-03105-z