Abstract
Tumors of the oral maxillofacial region consist of odontogenic and non-odontogenic tumors, and one often encounters tumor-like diseases that require differentiation from these tumors. When performing histopathological diagnoses of surgically resected tissues (surgical specimens), accurate evaluation of the extent of tumor expansion and the presence or absence of tumor in the surgical margin; as well as differentiation from similar diseases are necessary. Hence sectioning at the appropriate position is important. The present study examined the surgical specimens received since April 2008, which were subjected to microfocus X-ray CT (micro CT) imaging, sectioned based on the image findings, and processed for histopathological diagnosis. The micro CT images and histopathological findings were compared. Twenty-one cases were studied. The histologic types were squamous cell carcinoma in 16 cases (9 in mandibular gingiva, 4 in maxillary gingiva, 2 in buccal mucosa, and 1 inside mandibular bone), mucoepidemoid carcinoma in 1 case, ameloblastoma in 1 case, odontoma in 1 case, ectopic eruption of third molar in 1 case, and schwannoma in 1 case. In 18 cases of mandibular or maxillary bone resection for tumor removal, the presence or absence of bone resorption on micro CT image was in complete concordance with the presence or absence of histopathological bone invasion. Of 7 cases showing pressure type bone resorption on micro CT images, 6 cases showed expansive type and 1 case showed invasive type bone invasion histopathologically. Of 7 cases showing permeated type or moth-eaten type bone resorption on micro CT images, all showed invasive type bone invasion histopathologically. Therefore the patterns of bone resorption on micro CT images were almost consistent with the patterns of histopathological bone invasion. When comparing the presence or absence of tumor invasion in the mandibular canal and maxillary sinus, the results were concordant for the mandibular canal in all cases, and for the maxillary sinus in all but one case. While the internal state of the surgical specimen could not be discerned from the outer surface in the cases of odontoma and schwannoma because of the fibrous capsule and in the case of ectopic eruption of maxillary third molar due to the bony structure, the internal properties of these specimens could be identified on micro CT images, allowing sectioning at the appropriate position. The final diagnosis of oral diseases, including the extent of tumor invasion or expansion, depends on histopathological findings. For this purpose, appropriate sectioning is important and application of micro CT image is useful.
