BackgroundThe ongoing Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) aims to observe the natural course of papillary thyroid microcarcinoma (PTMC), develop a protocol for active surveillance (AS), and compare the long-term prognosis, quality of life, and medical costs between the AS and immediate surgery groups.MethodsThis multicenter prospective cohort study of PTMC started in June 2016. The inclusion criteria were suspicious of malignancy or malignancy based on fine needle aspiration or core needle biopsy, age of ≥18 years, and a maximum diameter of ≤1 cm. If there was no major organ involvement, no lymph node/distant metastasis, and no variants with poor prognosis, the patients were explained of the pros and cons of immediate surgery and AS before selecting AS or immediate surgery. Follow-up visits (physical examination, ultrasonography, thyroid function, and questionnaires) are scheduled every 6 months during the first 2 years, and then every 1 year thereafter. Progression was defined as a maximum diameter increase of ≥3, ≥2 mm in two dimensions, suspected organ involvement, or lymph node/distant metastasis.ResultsAmong 439 enrolled patients, 290 patients (66.1%) chose AS and 149 patients (33.9%) chose immediate surgery. The median follow-up was 6.7 months (range, 0.2 to 11.9). The immediate surgery group had a larger maximum tumor diameter, compared to the AS group (7.1±1.9 mm vs. 6.6±2.0 mm, respectively; P=0.014).ConclusionThe results will be useful for developing an appropriate PTMC treatment policy based on its natural course and risk factors for progression.

Background Distant metastasis of adenoid cystic carcinoma (ACC) is most commonly identified in the lung, but risk factors are still on debate. Methods Risk factors for lung metastasis were evaluated by using Cox proportional hazards model and Kaplan–Meier curves. Results Of 112 patients, 48% had distant metastasis; 94.4% of whom had lung metastasis. Univariable analysis revealed sublingual or minor salivary gland, tumor size ≥2.5 cm, and perineural invasion as risk factors (hazard ratio [HR]: 1.99 [1.02–3.91], 2.57 [1.19–5.58], and 2.46 [1.28–4.74], respectively), whereas size, perineural invasion, and local recurrence were risk factors in multivariable analysis (HR: 2.29 [1.05–4.96], 2.32 [1.09–4.96], and 2.68 [1.24–5.79], respectively). Conclusion Sublingual gland or minor salivary glands ACC has a higher risk of lung metastasis. If the site is not considered, the following factors increased the risk of lung metastasis; (a) size ≥2.5 cm, (b) perineural invasion, and (c) local recurrence.

Carcinoma ex pleomorphic adenoma (CXPA) arises from the primary or recurrent benign pleomorphic adenoma. The purpose of this study was to evaluate the clinical features that could be referenced in the differentiation. The medical records of 221 patients with pleomorphic adenoma and 15 patients with CXPA were retrospectively reviewed. Clinical characteristics, computed tomography and magnetic resonance imaging findings, and surgical pathology were analyzed. Patients with CXPA were older (55.1 vs 42.3; P < .01). Carcinoma ex pleomorphic adenoma was observed at higher rates in the minor salivary glands (24.9% vs 2.7%) and higher incidence of regional lymph node enlargement ( P = .04). While all CXPA showed a low-to-intermediate mean apparent diffusion coefficient value (ADC), most of pleomorphic adenoma had an intermediate-to-high ( P = .01). From this study, the following features should be considered as the clinical features of CXPA: (1) old age; (2) minor salivary gland tumor; (3) regional lymph node enlargement (>5 mm); and (4) low ADC findings.

Background and objectiveThoracic epidural analgesia can significantly reduce acute postoperative pain. However, thoracic epidural catheter placement is challenging. Although real-time ultrasound (US)-guided thoracic epidural catheter placement has been recently introduced, data regarding the accuracy and technical description are limited. Therefore, this prospective observational study aimed to assess the success rate and describe the technical considerations of real-time US-guided low thoracic epidural catheter placement.Methods38 patients in the prone position were prospectively studied. After the target interlaminar space between T9 and T12 was identified, the needle was advanced under real-time US guidance and was stopped just short of the posterior complex. Further advancement of the needle was accomplished without US guidance using loss-of-resistance techniques to normal saline until the epidural space was accessed. Procedure-related variables such as time to mark space, needling time, number of needle passes, number of skin punctures, and the first-pass success rate were measured. The primary outcome was the success rate of real-time US-guided thoracic epidural catheter placement, which was evaluated using fluoroscopy. In addition, the position of the catheter, contrast dispersion, and complications were evaluated.ResultsThis study included 38 patients. The T10–T11 interlaminar space was the most location for epidural access. During the procedure, the mean time for marking the overlying skin for the procedure was 49.5±13.8 s and the median needling time was 49 s. The median number of needle passes was 1.0 (1.0–1.0). All patients underwent one skin puncture for the procedure. The first-pass and second-pass success rates were 76.3% and 18.4%, respectively. Fluoroscopic evaluation revealed that the catheter tips were all positioned in the epidural space and were usually located between T9 and T10 (84.2%). The cranial and caudal contrast dispersion were observed up to 5.4±1.6 and 2.6±1.0 vertebral body levels, respectively. No procedure-related complications occurred.ConclusionReal-time US guidance appears to be a feasible option for facilitating thoracic epidural insertion. Whether or not this technique improves the procedural success and quality compared with landmark-based techniques will require additional study.Trial registration numberNCT03890640.