[Clinicopathological and immunohistochemical study of oral teratoid cyst].

OBJECTIVE: To investigate clinicopathological and immunohistochemical features of 31 cases of oral teratoid cyst. METHODS: Thirty-one cases of oral teratoid cyst according with Meyer's diagnosis criteria were retrospectively studied and their histochemistry and immunohistochemistry were performed from the files of Department of Pathology, School of Stomatology, Wuhan University between 1963 and 2003. RESULTS: Twenty-seven cases (87.10%) were children, and twenty-four cases were congenital. The ratio of male-to-female was 1:0.55, and the affected sites were floor of mouth (22 cases) and tongue (8 cases). Clinical findings were nonspecific, and prognosis was good following complete excision. Histology indicated that squamous, respiratory and/or gastrointestinal epithelium consistiuted basic structure of teratoid cyst in addition to simple cuboidal epithelium in 8 cases. Antibody against AE1/AE3 was strongly expressed and CK16 was weak in four types of epithelial lining of oral teratoid cyst. Expression of AE1, CK7, 8/18, 19 varied in superficial, suprabasal and basal cells of squamous epithelium but were strong in respiratory, gastrointestinal and simple columnar epithelium; only gastrointestinal epithelium expressed CK20 heterogeneously. CONCLUSIONS: Oral teratoid cyst showed the highest incidence in children, and floor of mouth and tongue were mostly affected sites. Features of histology were complex, and immunohistochemistry indicated that epithelium of oral teratoid cyst shared similar patterns of cytokeratin with counterpart of normal tissues, showing different origin and differentiation of epithelial lining of the present cyst.

[A histological and ultrastructural study of the tidemark in human condylar cartilage].

OBJECTIVE: To study the histology and ultrastructure of the tidemark in the adult condylar cartilage and their significance. METHODS: After embedded in paraffin, 50 adult condyles were stained with HE, partly with Van-Gieson and histochemical methods, then observed by light microscope. 3 cases of the tidemark region were observed by transmission electron microscope, another 5 cases were studied by scanning electron microscope. RESULTS: In the tidemark region, there had shown the presence of the AKP and calcium, absence of the proteoglycan, abundance of the membrane-bound matrix vesicles, crystals of hydroxyapatite and lipid nodule-like substances, which were often observed in the load-bearing areas. The collagen fibrils of the noncalcified cartilage crossed the tidemark gradiently and were continuous with those of the calcified cartilage; a band of horizontal fibrils surrounded the whole tidemark region, which was wider in the load-bearing areas than that in the nonload-bearing areas and which interweaved with the gradient fibrils so as to form a net. Digested with papain, the surface of the tidemark was highly undulating, and a lot of chondrocyte lacunae were seen on the surface, which were surrounded by calcified tissues. CONCLUSIONS: In the region of the tidemark, physiological calcification takes place and is more active in the load-bearing areas; gradient and horizontal fibrils interweave with each other, which is correlated with the force on the articulation.