Primary Intraosseous Squamous Cell Carcinoma Arising from a Dentigerous Cyst of the Maxillary Wisdom Tooth.

The World Health Organization defines primary intraosseous squamous cell carcinoma (PIOSCC) as a squamous cell carcinoma (SCC) arising primarily within the jaws and having no connection with the oral mucosa. Here, we report a case of PIOSCC in which it was difficult to differentiate the condition from pericoronitis of an impacted maxillary wisdom tooth. The patient was a 27-year-old pregnant woman with a pain in the right maxillary wisdom tooth. The pain was diagnosed as pericoronitis of the right maxillary wisdom tooth, and the tooth was extracted under local anesthesia. During extraction, soft tissue was observed in the coronal part of the tooth, and it was diagnosed as SCC arising in a dentigerous cyst. Because the tumor may still be present, surgical resection was performed under general anesthesia. There has been no recurrence or metastasis at the 1-year follow-up. This case was histopathologically considered from being a benign odontogenic tumor to a malignant tumor. However, it revealed an extensive aberrant type and invasion equivalent to SCC. Thus, the histopathological diagnosis was PIOSCC arising from a dentigerous cyst. Although advanced cases of PIOSCC have been published, diagnosis of PIOSCC in the early stages is rare. In this case, we diagnosed pericoronitis of an impacted maxillary wisdom tooth and extracted the tooth. Therefore, we discovered it accidentally. In the early stages, diagnosis can be difficult both clinically and histopathologically.

Ten-year Clinical Trends among 575 Consecutive Oral Cancer Patients at Tokyo Dental College Oral Cancer Center.

The facilities comprising Tokyo Dental College (TDC) -the college itself and its medical institutions at Suidobashi, Ichikawa, and Chiba - have been officially recognized as a center for treating oral cancer. The TDC Oral Cancer Center (OCC) was established on April 1, 2006. It provides comprehensive medical care, including that aimed at recovery of postoperative function, such as restoration of stomatognathic function, dysphagia therapy, and placement of maxillary prostheses. The purpose of this study was to investigate patient trends at TDC-OCC over the 10 years following its establishment in order to determine how the safe and high-quality cancer care already provided might be even further improved. Oral cancer patients attending TDC-OCC between April 2007 and March 2017 were investigated. Clinical information was obtained from medical records and analyzed, including that on patient numbers, age, sex, primary site of tumor, clinical stage, and surgery provided. There were 758 new cases, and the number of new cases showed an annual increase. Among the total number of new patients, 575 (75.9%) represented primary cases. The number of operations also showed an increase, which correlated with the increase in the number of patients. The incidence in oral cancer has increased in several countries, including Japan. Oral cancer can be observed macroscopically and touched. In contrast to with cancers at many other sites, and despite various diagnostic devices for early detection having been developed, however, cases are often advanced when first encountered. Many advanced cases were treated at TDC-OCC, and the number of reconstructive operations following progressive cancer also increased over time.

Magnetic resonance imaging findings of styloglossus and hyoglossus muscle invasion: Relationship to depth of invasion and clinical significance as a predictor of advisability of elective neck dissection in node negative oral tongue cancer.

PURPOSE: By comparing styloglossus and hyoglossus muscle invasion (SHMI) of oral tongue squamous cell cancer (OTSCC) on MR imaging to pathological depth of invasion (DOI) and prognosis, we aimed to evaluate the clinical significance of MR imaging findings of SHMI. METHOD: Forty-five, early stages and clinically N0 OTSCCs were retrospectively reviewed. Data included pathological DOI, DOI on MR imagings, two-year potential cervical lymph node positive, locoregional control, disease-free survival, and overall survival. Data were statistically compared between the groups with MR evidence of SHMI (SHMI+) and without MR evidence of SHMI (SHMI-). RESULTS: There were 17 SHMI + and 28 SHMI-. Elective neck dissections performed on 13 cases revealed five node positive cases, all of which were SHMI + . Pathological DOI in SHMI + was significantly larger than SHMI- (average 9.0 vs 4.6 mm, p < 0.001). All SHMI + revealed pathological DOI larger than 4 mm. The two-year potential cervical lymph node positive rate of SHMI + was significantly higher than SHMI- (p =  0.01). Locoregional control rate and disease-free survival of SHMI+ were significantly lower than in SHMI- (p =  0.02). There was no significant difference in overall survival. Interobserver agreement in evaluation of SHMI on MR imaging was good (kappa value = 0.72, p <  0.001). CONCLUSIONS: Pathological DOIs of SHMI + were all larger than 4 mm, which is the cut-off point that National Comprehensive Cancer Network recommends for neck dissection, and SHMI + had a worse prognosis than SHMI-. SHMI + can be used as a criterion for elective neck dissection.

Undetectability of oral tongue cancer on magnetic resonance imaging; clinical significance as a predictor to avoid unnecessary elective neck dissection in node negative patients.

METHODS:: We retrospectively reviewed early stage oral tongue cancer patients treated with radical surgery with clinically N0, between May 2009 and February 2016. Collected data include age, sex, pathological DOI, DOI on MRI, locoregional control rate, disease-free survival rate, and overall survival rate. These data were statistically compared between the detectable lesion (DL) group and undetectable lesion (UL) group on MRI. Interobserver agreement in evaluation of detectability of the oral tongue cancer was assessed by k statistics. RESULTS:: Total of 53 patients were studied, and 28 were DLs and 25 ULs. Pathological DOI in UL was significantly smaller than that of DL (average 1.7 vs 4.6 mm, p < 0.001). Cut-off value between UL group and DL group was 3.5 mm (sensitivity 96 %, specificity 75 %). 96 % of ULs had pathological DOI smaller than 4 mm, the recommended cut-off value for neck dissection. There was no significant difference in locoregional control rate (p = 0.24), disease-free survival rate (p = 0.24) or overall survival rate (p = 0.92). Interobserver agreement in evaluation of detectability on MRI was very good ( k-value = 0.89, p < 0.001). CONCLUSIONS:: When oral tongue cancer is not detected on MRI, it indicates pathological DOI being smaller than 4 mm, which may imply that elective neck dissection is unnecessary.