正中口蓋部に発生した非角化性原始性嚢胞の１例とその文献的考察

Abstract

In recent years, there has been some controversy concerning the relation between primordial cyst and odontogenic kerato cyst and a definite conclusion has not been obtained yet.Further, due to vague criteria of diagnosis for fissural cyst, classification of jaw cyst seems to be confused.We experienced a patient who underwent several examinations under clinical diagnosis of fissural cyst and finally diagnosed as non-keratinizing primordial cyst.Thus, we describe on an outline of this case addiscuss the classification of jaw cyst.The patient was a 25-year-old female who visited our hospital with chief complaint of pain of median palate. Examination revealed a relatively discrete swelling about pigeon egg size in the median palate from which a fluid with pus cells was aspirated.X-ray findings revealed a discrete, pear-shaped, bone radiolucent picture about pigeon egg size in the region between the bilateral median incisal teeth and the hard palate, and bilateral inflammation of the central incisor root spread centrifugally. Under a clinical diagnosis of fissural cyst, cystectomy was conducted under local anesthesia on December 21, 1984. Histopathological findings revealed that the cystic wall was thin and the epithelial layer consisted of stratified squamous epithelium. Loss of epithelial projection to the subepithelium and alignment of the cylindrical basal cells in the lowest layer of epithelium were noted. Abcess and hemorrhagic nest as well as cellular infiltration with severe inflammation were observed in the subepithelium. The epithelium was invaded by inflammation and epithelial alignment was disturbed. Namely, an established diagnosis of non-keratinizing primordial cyst was made from the following points: 1) pathological findings accorded with the findings of primordial epithelium, 2) no relation between this lesion and the incisal canal was observed from the findings during operation, 3) the lesion was distinguished from nasopalatine cyst, 4) there was no definite evidence to diagnose fissural cyst and 5) there was full significance of existence of non-keratinizing primordial cyst, In this paper, we further discussed the classification of jaw cyst.