Fungal infection causing nasal swelling and lumps in cats

Abstract

Cryptococcosis is a severe systemic mycosis affecting humans and animals, caused primarily by members of the <i>Cryptococcus neoformans</i>/<i>Cryptococcus gattii</i> species complex. In cats, it is the most common systemic fungal infection and may present with non-specific signs involving the upper respiratory tract, skin, lymph nodes, eyes, or the central nervous system. This study presents two feline cases of cryptococcosis diagnosed by cytological examination and provides an updated literature review. Fine-needle aspiration biopsies were performed in two cats with chronic nasal swelling and submandibular enlargement. Cytological smears stained with hematoxylin and eosin revealed spherical to oval yeast-like organisms with a characteristic thick, non-staining capsule, narrow-based budding, and absence of pseudohyphae, consistent with <i>Cryptococcus</i> spp. Based on cytological findings, both patients were treated with oral itraconazole, resulting in favorable clinical outcomes. A limitation of this study is the lack of mycological culture or molecular confirmation, owing to the owners’ refusal of further diagnostic testing. These cases highlight the diagnostic value of cytology as a rapid tool for differentiating fungal infections from neoplastic processes. Early diagnosis and antifungal therapy are crucial for successful management. From a One Health perspective, feline cryptococcosis may indicate shared environmental exposure risks relevant to both animal and human health.