Tomohiro Kawasumi, Takao Hamamoto, Takashi Ishino, Tsutomu Ueda, Sachio Takeno
Background and Clinical Significance: Eosinophilic sialodochitis (ES), also known as sialodochitis fibrinosa, is a rare disorder characterized by recurrent salivary gland swelling caused by intraductal eosinophilic mucous plugs. Typical histopathological findings include eosinophils and Charcot-Leyden crystals within ductal secretions, and characteristic imaging findings include salivary duct dilatation and glandular swelling. Although rare cases associated with sialolithiasis or calcification have been reported, high-attenuation material within the salivary duct on computed tomography (CT) has not been clearly described in ES. Case Presentation: A 56-year-old woman with allergic rhinitis presented with recurrent swelling and pain in the right submandibular area. CT and ultrasonography revealed a large sialolith in the right submandibular gland and dilatation of Wharton's duct. She underwent right submandibular gland excision for presumed chronic obstructive submandibular sialadenitis with a sialolith. Soon after surgery, she developed recurrent swelling of the right floor of the mouth, and CT showed persistent high-attenuation material along Wharton's duct without residual sialolith. Ductal massage discharged a brownish gelatinous material. Histopathological examination revealed numerous eosinophils and Charcot-Leyden crystals in both the discharged mucous plug and decalcified sialolith, fulfilling Baer's diagnostic criteria for ES. Physical extraction and anti-allergic medications were insufficient, whereas ductal irrigation with saline and triamcinolone acetonide markedly reduced mucous plug discharge. Symptoms were controlled during 18 months of follow-up. Conclusions: Retained eosinophilic mucin in ES may appear as high-attenuation ductal material on CT and contribute to salivary stasis and sialolith formation.