Masaaki Karino

Applicability of preoperative nuclear morphometry to evaluating risk for cervical lymph node metastasis in oral squamous cell carcinoma.

Background We previously reported the utility of preoperative nuclear morphometry for evaluating risk for cervical lymph node metastases in tongue squamous cell carcinoma. The risk for lymph node metastasis in oral squamous cell carcinoma, however, is known to differ depending on the anatomical site of the primary tumor, such as the tongue, gingiva, mouth floor, and buccal mucosa. In this study, we evaluated the applicability of this morphometric technique to evaluating the risk for cervical lymph node metastasis in oral squamous cell carcinoma. Methods A digital image system was used to measure the mean nuclear area, mean nuclear perimeter, nuclear circular rate, ratio of nuclear length to width (aspect ratio), and nuclear area coefficient of variation (NACV). Relationships between these parameters and nodal status were evaluated by t-test and logistic regression analysis. Results Eighty-eight cases of squamous cell carcinoma (52 of the tongue, 25 of the gingiva, 4 of the buccal mucosa, and 7 of the mouth floor) were included: 46 with positive node classification and 42 with negative node classification. Nuclear area and perimeter were significantly larger in node-positive cases than in node-negative cases; however, there were no significant differences in circular rate, aspect ratio, or NACV. We derived two risk models based on the results of multivariate analysis: Model 1, which identified age and mean nuclear area and Model 2, which identified age and mean nuclear perimeter. It should be noted that primary tumor site was not associated the pN-positive status. There were no significant differences in pathological nodal status by aspect ratio, NACV, or primary tumor site. Conclusion Our method of preoperative nuclear morphometry may contribute valuable information to evaluations of the risk for lymph node metastasis in oral squamous cell carcinoma.

A modified pectoralis major myocutaneous flap technique with improved vascular supply and an extended rotation arc for oral defects: A case report

The pedicled pectoralis major myocutaneous (PMMC) flap is versatile, and is widely used for the treatment of surgical defects following oral cancer resection. Although free-tissue transfer of a vascularized free flap is often preferred, the clinical benefits of the PMMC flap should not be overlooked. The conventional technique of harvesting a PMMC flap involves a single vascular supply from the pectoral branch of the thoracoacromial artery. However, this approach compromises the distal skin island of the flap, and requires an indirect blood supply via communicating vessels, which increases the potential risk of partial distal flap necrosis. When harvesting a PMMC flap for oral and maxillofacial reconstruction, preservation of the lateral thoracic artery and use of the subclavian route are alternatives that ensure sufficient blood supply and an increased rotation arc. Such an approach enables the harvesting of a PMMC flap that can reach the entire oral cavity, including the infraorbital region, palate, middle pterygopalatine fossa and nasopharynx, with no risk of vascular insufficiency to the distal skin island. In conclusion, the technique described in the present study was able to improve the blood supply of the distal PMMC flap and increase its rotation arc.