Background: Follicular tumors include follicular thyroid adenomas and carcinomas; however, it is difficult to distinguish between the two when the cytology or biopsy material is obtained from a portion of the tumor. The presence or absence of invasion in the resected material is used to differentiate between adenomas and carcinomas, which often results in the unnecessary removal of the adenomas. If nodules that may be follicular thyroid carcinomas are identified preoperatively, active surveillance of other nodules as adenomas is possible, which reduces the risk of surgical complications and the expenses incurred during medical treatment. Therefore, we aimed to identify biomarkers in the invasive subpopulation of follicular tumor cells. Methods: We performed a spatial transcriptome analysis of a case of follicular thyroid carcinoma and examined the dynamics of CD74 expression in 36 cases. Results: We identified a subpopulation in a region close to the invasive area, and this subpopulation expressed high levels of CD74. Immunohistochemically, CD74 was highly expressed in the invasive and peripheral areas of the tumor. Conclusions Although high CD74 expression has been reported in papillary and anaplastic thyroid carcinomas, it has not been analyzed in follicular thyroid carcinomas. Furthermore, the heterogeneity of CD74 expression in thyroid tumors has not yet been reported. The CD74-positive subpopulation identified in this study may be useful in predicting invasion of follicular thyroid carcinomas.

Because the corona disaster made group medical training difficult, we conducted resuscitation training for new students and basic medical skills training for fourth-year students without face-to-face instruction using video learning, assessment, and ICT. In the resuscitation training, the students were allowed to take a mannequin home and film themselves performing the resuscitation while learning by video. Later, group and peer assessment were conducted via Zoom, and a significant increase in self-assessment was observed. In the basic medical skills training, the students filmed their own implementation at their own pace while learning by video, and the teachers later conducted video assessment and feedback. The lack of face-to-face instruction made it possible to implement the limb spine training, which had not been possible in previous years. It is necessary to adjust the timing of the video registration by the students and the video assessment by the teachers, and to make further improvements to the system.