Ultrasonographic and Radiographic Features of Mucormycosis Causing Generalized Lymphadenopathy and Cranioventral Pulmonary Masses in an Immunocompetent Cat

A 4-year-old domestic shorthair cat from Switzerland presented with seizures and peripheral lymphadenomegaly. Thoracic radiographs demonstrated cranioventral pulmonary masses and enlargement of the cranial mediastinal and tracheobronchial lymph nodes. Abdominal ultrasonography revealed generalized lymphadenopathy characterized by rounded, homogeneously hypoechoic lymph nodes with an effaced hilus. Imaging differentials included lymphoma, feline coronavirus-associated granulomatous disease, and other fungal infections; cytology and culture confirmed mucormycosis. The pulmonary masses and lymphadenomegaly initially responded to azole therapy; however, they later progressed despite further treatment, and the cat was humanely euthanized 8 months after diagnosis. This case highlights an atypical presentation of mucormycosis in an immunocompetent adult cat, with an unusual lesion distribution localized within the lymphatic system, respiratory system, and suspected central nervous system involvement.