EXPRESS: Nasopharyngeal eosinophilic sclerosing fibroplasia in a 15-year-old cat: expanding the anatomical and age spectrum of the disease

A 15-year-old spayed female domestic shorthair cat was evaluated for chronic progressive stertor, mucopurulent nasal discharge and intermittent apnoeic episodes. CT revealed a soft-tissue mass occupying the nasopharynx and partially obstructing the choanae. Nasopharyngoscopy confirmed a firm, pale, multilobulated lesion. Partial endoscopic debulking of the mass was performed, although further sampling was limited by post-procedural haemorrhage. Histopathology demonstrated dense eosinophilic inflammation with marked sclerosing fibroplasia, consistent with feline eosinophilic sclerosing fibroplasia (FESF); no histological features suggestive of lymphoma, carcinoma, fungal disease, or inflammatory polyps were identified. Prednisolone was initially administered to minimise the risk of post-procedural inflammatory nasopharyngeal stenosis and subsequently continued for 45 days following histological confirmation of FESF. Two months later, CT and nasopharyngoscopy demonstrated complete anatomical resolution with full remission of clinical signs.