小脳膿瘍を併発した口腔底嚢胞の1症例—甲状舌管嚢胞の診断に関する考察

A Case with a Cyst in the Oral Floor who Developed a Cerebellar Abscess

はじめに

　甲状舌管嚢胞は胎児期の甲状舌管の遺残物であり，正中頸嚢胞という臨床診断名が示すとおり，前頸部正中に存在することが多いが，時には口腔底腫瘤として臨床症状をあらわして診断上問題になることがある。今回我々は小脳膿瘍を併発した口腔底嚢胞の1症例を経験したが，嚢胞壁の病理学的所見からは類表皮嚢胞の診断が妥当と思おれたものの，手術所見として嚢胞から舌骨につながる索状物があったため甲状舌管嚢胞の可能性もあると考えられたので，ここに甲状舌管嚢胞の診断に関する考察を含め，症例を報告する。

A 41-year-old male case with a cyst in the oral floor who had repeatedly ruptured the cyst by himself with a needle and developed a cerebellar abscess was reported. The patient complained of severe positional vertigo on admission. The inter-nal surface of the cyst was covered by a stratified squamous cell epithelium. The cyst wall contain-ed no thyroid or salivary tissue. Although the diagnosis of an epidermoid cyst was most probable, the possibility of a thyroglossal cyst was also proposed, because the inferior surface of the cyst was connected to the hyoid bone by a string-like structure.