Static bone cavity of the mandible: Computed tomography findings with histopathologic correlation.

PURPOSE: To review computed tomography (CT) findings of histopathologically examined static bone cavities in order to determine whether an additional pathogenesis may play a role in this disease. MATERIAL AND METHODS: Four patients with histopathologically examined static bone cavities were included in this retrospective study. Location, appearance of bone remodeling, tissue characteristics, and contrast enhancement of the cavity were assessed on CT images. CT findings were then compared with the histopathological findings. RESULTS: Static bone cavity was found in the lingual molar region in three patients and in the lingual cuspid region of the mandible in one patient. Both fatty and soft tissues were present in the cavities of all four patients. Attenuation of the soft tissue in the cavities was found to be different from that of the submandibular gland. The soft tissue showed enhancement with contrast-enhanced CT in three patients. For all patients, the histopathologic content of the static bone cavity included fat, soft tissue, and abnormal vasculature. The thickened vein wall in the abnormal vasculature was observed. Aberrant tissue of the submandibular gland was not found in any of the static bone cavities. CONCLUSION: Contrast enhancement of the soft tissue on the contrast-enhanced CT images suggests the presence of vasculature in the cavities. Histopathological examination confirmed the presence of fatty tissue and dilated abnormal vessels, and the absence of salivary gland tissue in the cavities. These findings show that vascular structures are prominent in tissues found in static bone cavities.

Lymphatic endothelium of the human tongue expresses multiple leukocyte adhesion molecules.

The expression of leukocyte adhesion molecules on lymphatic vessels of the human tongue was examined using histochemical and immunohistochemical methods. Three different types of lymphatic vessels were distinguished: type I vessels expressed intercellular adhesion molecule-1 (ICAM-1), platelet-endothelial cell adhesion molecule-1 (PECAM-1), and endothelial cell-selectin (ELAM-1); type II vessels expressed ICAM-1 and PECAM-1; and type III vessels expressed PECAM-1 only. The lymphatic vessels located very close to the oral epithelium (lymphatic capillaries) and the other lymphatic vessels near the oral epithelium were type I. The lymphatic vessels in the submucosal connective tissue (collecting lymphatic vessels) were type II and type III. The results suggest that there may be functional differences in the lymphatic endothelium, where lymphatic capillaries are more active than collecting lymphatic vessels in lymphocyte migration from tissue into the lymphatic vessels.

Immunohistochemical study on leukocyte adhesion molecules expressed on lymphatic endothelium.

Leukocyte adhesion molecules expressed on the lymphatic endothelium in human small intestine and submandibular lymph node were studied immunohistochemically. Lymphatic capillaries in the lamina propria, mucosal muscle layer, and submucosal connective tissue of the intestine and in the capsule of the lymph node showed strong expression of platelet-endothelial cell adhesion molecule-1 (PECAM-1). A few lymphatic capillaries that weakly expressed intercellular adhesion molecule-1 (ICAM-1) were found in the capsule of the lymph node but in the small intestine, no lymphatic capillaries expressed detectable amounts of ICAM-1. Lymphatic capillaries also did not express detectable amounts of endothelial cell-selectin in the small intestine and lymph node. When lymphocytes migrate from tissue into lymphatic capillaries, multiple adhesion molecules may not be required for the migration. PECAM-1, however, may contribute to adherence of lymphocytes to lymphatic endothelium and the expression of adhesion molecules on lymphatic endothelium may be different between tissues.

Immunohistochemical demonstration of lymphatic vessels in human dental pulp.

The existence of lymphatic vessels in dental pulp has been a matter of continuing controversy because of the difficulty of discriminating them in ordinary stained tissue sections. Recently, we have succeeded in establishing a new identification method for lymphatic vessels in human frozen sections by using a commercial monoclonal antibody specific for the human thoracic duct and anti-human laminin antiserum. The present study aimed to examine the lymphatic vessels in human dental pulp using the new immunostaining method, and compared the results with those in human small intestine. The study clearly demonstrated the distribution of lymphatic vessels in human dental pulp. Large lymphatic vessels are located in the central part of the pulp and there are small lymphatic vessels in the periphery of the pulp. This suggests that lymphatic drainage of the human dental pulp starts from the periphery of the pulp and collects in the central part of the pulp. A notable difference between the small intestine and dental pulp was found in the immunoreactivity of lymphatic vessels to anti-human laminin anti-serum. In small intestine, immunoreactivity was significantly weaker than that of the blood vessels, whereas in dental pulp, that of lymphatic vessels was almost the same as blood vessels, except for some lymphatic vessels showing very weak reactivity. These findings suggest that the development of the basement membrane in both the lymphatic and blood vessels of human dental pulp is not as marked as in other tissue.

Comparison of magnetic resonance imaging and gross findings regarding masseter muscle aponeuroses in cadavers.

OBJECTIVES: The main objective of this study was to compare the actual distribution and thickness of aponeuroses in cadavers with the distribution and thickness as determined by means of magnetic resonance imaging for the sake of evaluating magnetic resonance imaging as a diagnostic modality for assessing masseter muscle aponeuroses. STUDY DESIGN: The aponeuroses of 26 masseter muscles from 13 intact cadavers were examined by magnetic resonance imaging. RESULTS: The ratio of concordance between gross findings and magnetic resonance imaging findings was 99.0%, although depiction of thin parts of the aponeuroses on magnetic resonance imaging was poor. CONCLUSIONS: Magnetic resonance imaging was useful as a diagnostic modality in the assessment of masseter muscle aponeuroses. Aponeuroses were distributed throughout almost the entire masseter muscle, although almost no aponeuroses were seen below the lower half of the anterior margin. This was thought to be a characteristic finding of masseter aponeuroses.

Lymphatic endothelium expresses PECAM-1.

The expression of adhesion molecules on the lymphatic endothelium of human small intestine and submandibular lymph node was studied immunohistochemically with the antibodies for selectin family and Ig superfamily members. In both small intestine and submandibular lymph node, lymphatic endothelium did not express intercellular adhesion molecule-1 and endothelial cell-selectin but expressed platelet-endothelial cell adhesion molecule-1 (PECAM-1). Though lymphatic vessels may not have a positive function in leukocyte rolling and adhesion, lymphatic endothelium may interact with leukocytes, with PECAM-1 playing a role.