Thymic epithelial tumors represent the most common neoplasms of the anterior mediastinum, while atypical type A thymoma is a rare subtype of thymoma. On the morphological basis of type A thymoma, this tumor exhibits some atypical histological features, such as abundant cells, increased mitotic counts, tumor necrosis, and increased Ki67 index. At present, the clinical and pathological data of this tumor is still available. Since it was formally named, 16 cases have been reported around the world. In order to improve the understanding of the disease, this article reviews the related literature and tries to elaborate the atypical type A thymoma from the aspects of pathological features, clinical manifestations, epidemiology and differential diagnosis.
Objective To compare the differences in clinicopathological features, molecular phenotypes, and prognosis between atypical type A thymoma (AAT) and classic type A thymoma (TAT), and to clarify the aggressive nature of AAT. Methods The data of AAT patients (AAT group) and classic TAT patients (TAT group) who underwent surgical resection for thymoma at West China Hospital of Sichuan University between January 2016 and November 2024 were retrospectively collected. Comparisons on the clinical data, histopathology, immunohistochemistry (CD20, Ki67), GTF2I mutation status, and survival outcomes were performed between the two groups. Results A total of 53 patients were enrolled, including 22 in the AAT group and 31 in the TAT group. There was no significant difference in age, sex, or initial presenting symptoms between the two groups (P>0.05). Compared with the TAT group, the AAT group had larger tumors [(5.6±2.7) vs. (4.1±2.0) cm, P=0.043], a lower proportion of Masaoka stage Ⅰ (31.6% vs. 61.3%, P=0.041), and worse survival outcomes [progression-free survival: hazard ratio (HR)=0.046, 95% confidence interval (CI) (0.23, 0.89), P=0.004; overall survival: HR=0.36, 95%CI (0.19, 0.69), P=0.013]. Pathologically, the AAT group showed more mitotic figures (mean 6/2 mm2), and tumor necrosis was observed in 45.5% of cases. There was no statistically significant difference in the CD20 expression rate (20.0% vs. 41.9%), Ki67 index [(11.0±6.0)% vs. (8.0±6.9)%], or GTF2I mutation rate (86.7% vs. 92.3%) between the two groups (P>0.05). Conclusions AAT is a subtype of TAT with distinct aggressive pathological features, including higher mitotic activity, a tendency for necrosis, and a greater propensity for recurrence and metastasis. Pathological diagnosis should integrate morphology and molecular testing to guide more aggressive treatment and follow-up strategies.
Objective To know about the baseline and quality of clinical prophylaxis and treatment study on communicable diseases in China, by identifying and assessing the clinical studies published in Chinese Journal of Infectious Diseases for 18 years. Method Handsearching page by page to identify and register the clinical studies from the journal, the definition of randomized controlled trial (RCT) and controlled clinical trial (CCT) strictly according to the Cochrane Collaboration Handbook (1997). Results There were totally 214 clinical studies during the 18 years, including 67 RCTs, 67 CCTs and 80 Non-CCTs. The average sample size of the RCTs was 103.0±70.2 (range from 17 to 296). Counted by every 5 years period (3 years period from 1998 to 2000), the proportion of RCTs in clinical studies was increasing steadily. The proportion were 22.9% from 1983 to 1987 (11/48), 29.2% from 1988 to 1992 (14/48), 41.9% from 1993 to 1997 (26/62), 28.6% from 1998 to 2000 (16/56) respectively. The main diseases studied in 214 clinical studies include: virus hepatitis (65 studies), hemorrhagic fever with renal syndrome (19 studies), typhoid fever (11 studies), bacterial infection (13 studies), bacillary dysentery (5 studies), epidemic encephalitis B (3 studies) and parasitosis (9 studies). Conclusion RCT study design should be applied as much as possible. The quality of clinical studies on communicable diseases in China remains to be improved. Multi-center and large-scale collaborative study is worthy to advocate.
Objective To evaluate the imaging features of pancreatic neuroendocrine carcinoma （PNEC）. Methods The imaging data of 7 patients with PNECs proved by surgery and pathology in West China Hospital of Sichuan University from Jul. 2007 to Dec. 2012 were retrospectively analyzed. The boundary， density， and strengthening features of tumor were observed. Results Seven tumors were found in all patients with 2 in pancreatic head， body， and tail， respectively. There was 1 tumor in pancreatic body and tail too. Five tumors were with unclear boundary. Five tumors had hypodense enhancement and 2 had isodense enhancement. Two cases had distal pancreatic duct dilation. None of them had liver metastases or lymph node involvement. Conclusion PNEC has certain characteristics on imaging. It is difficult to distinguish diagnosis from pancreatic cancer.