LVI is an adverse prognosticator in FOM SCC and indicates postoperative radiotherapy. Further study is required to investigate the importance of invasive front. © 2015 Wiley Periodicals, Inc. Head Neck 38: E1528-E1534, 2016.

4. Laryngoscope, 127:849-854, 2017.

Resection of the submandibular gland is generally undertaken as an integral component of level I neck dissection for oral cancer. However, it is unclear whether lymph nodes are present within the submandibular gland which may form the basis of lymphatic spread. Our purpose was to investigate the frequency of lymph nodes within the submandibular gland, and the incidence and mechanism of submandibular gland involvement in floor of mouth cancer. Retrospective review of 177 patients with oral cancer undergoing neck dissection. Original pathology slides of floor of mouth cases were re-reviewed by two pathologists to determine frequency of intraglandular lymph nodes, and incidence and mechanism of submandibular gland involvement by cancer. The overall incidence of cervical metastases was 36.4 %, of whom 44 % had level I metastases. Level I metastases were significantly more common in floor of mouth than tongue cancers (p = 0.004). Among 50 patients with floor of mouth cancer undergoing re-review of pathology slides, intraglandular lymph nodes were not found in any of 69 submandibular glands. Submandibular gland involvement by cancer was present in two patients, representing 1 % of all oral cancers, and 4 % FOM cases. Mechanisms of involvement were direct extension, and by an apparent novel mechanism of carcinoma growing along bilateral Wharton's ducts. Despite the high incidence of level I metastasis in floor of mouth, lymphatic metastases to submandibular gland are unlikely based on absence of intraglandular lymph nodes. We describe a previously unreported mechanism of submandibular gland involvement.

Interobserver agreement in the diagnosis of LVI was substantial. The POI at the 50% and 20% cut-offs is moderately reproducible, and has prognostic value in FOM SCC. Further studies are necessary to establish the optimum quantitative cut-off for the POI.

Objective Oral cavity squamous cell carcinoma (SCC) may present with early invasion of mandibular bone. Preoperative planning of surgery is essential considering patient's postoperative quality of life. Our purpose was to evaluate the efficacy of computer tomography scan (CT) and magnetic resonance imaging (MRI) in detecting mandibular bone involvement in oral SCC. Methods A retrospective study was conducted on 98 patients with SCC of floor of mouth, lower alveolus and retromolar trigone operated on with curative intent. Preoperative CT and MRI scans were re-reviewed by a consultant radiologist and original histology slides were re-reviewed by 3 pathologists. Results Forty-five patients were included in the final study. Combined CT and MRI had a sensitivity of 100% and a specificity of 72%. Conclusion The results suggest that combined CT and MRI have diagnostic utility in detecting mandibular invasion by oral cancer, but with a significant false positive rate.