Abstract
Simple SummaryThymic lymphoepithelial carcinoma (TLEC) is a rare primary thymic carcinoma. EBV infection has been reported among some individuals with TLEC tumor cells. Instances of EBV infection in other types of thymic epithelial tumor have been reported at lower rates, which suggests that EBV infection may have an important influence on the carcinogenesis of TLEC, though the etiology is unknown. Though there have been reports of thymic carcinoma including TLEC, there are few reports on the analysis of TLEC alone, and only case-reports were reported. We conducted this review by accumulating 58 cases in 34 reports to date. TLEC is a highly malignant tumor with poor prognosis, as affected patients have a median survival time of 22 months, according to 58 cases from the literature, while 5-year survival rate is 34.4%. Presently, prognosis is not considered to be affected by the presence or absence of EBV positivity.Thymic lymphoepithelial carcinoma (TLEC) is a primary thymic carcinoma that accounts for about 14% of all thymic epithelial tumors and is classified into 14 types. The histological morphology is similar to lymphoepithelioma, a type of undifferentiated nasopharyngeal carcinoma. It has been reported that squamous carcinoma accounts for approximately 80% of thymic carcinoma, followed by TLEC, which accounts for 6%. TLEC has been reported to be associated with Epstein-Barr virus (EBV), with EBV infection in TLEC tumor cells first noted by Lyvraz et al. in 1985. Tumors shown to be EBV-positive are classified as TLEC if lymphoplasmacytic infiltration is lacking. However, only about 50% of the cases are positive for EBV, which is lower compared to nasopharyngeal lymphoepithelioma. Instances of EBV infection in other types of thymic epithelial tumor have been reported at lower rates, which suggests that EBV infection may have an important influence on the carcinogenesis of TLEC, though the etiology is unknown. TLEC is a highly malignant tumor with poor prognosis, as affected patients have a median survival time of 22 months, according to 58 cases from the literature, while the 5-year survival rate is 34.4%. Presently, prognosis is not considered to be affected by the presence or absence of EBV positivity.
Highlights
Thymic lymphoepithelial carcinoma (TLEC) is defined as a primary thymic undifferentiated or poorly differentiated squamous cell carcinoma or undifferentiated carcinoma, with significant prominent reactive lymphoplasmacytic infiltration identical to undifferentiated nasopharyngeal carcinoma [1,2]
In the ITMIG database, squamous cell carcinoma accounts for approximately 80% of thymic carcinomas, while TLEC accounts for 6% [15]
The Japanese Association for Research on Thymus (JART), which maintains a database of thymic tumors in Japan, reports that TLEC accounts for 1.3% of thymic tumors [16]
Summary
Thymic lymphoepithelial carcinoma (TLEC) is defined as a primary thymic undifferentiated or poorly differentiated squamous cell carcinoma or undifferentiated carcinoma, with significant prominent reactive lymphoplasmacytic infiltration identical to undifferentiated nasopharyngeal carcinoma [1,2]. Cancers in organs other than a nasopharynx, which show histological similarities to that of lymphoepithelioma, are called lymphoepithelioma-like carcinomas (LELC) or lymphoepithelial carcinomas (LEC). In both lymphoepithelioma and LEC, the EBV genome is detected in tumor cells, and EBV is closely associated with their tumorigenesis [3,4]. The EBV genome has been detected in 90% of nasopharyngeal lymphoepitheliomas and 10% of gastric cancers [3,4]. Thymic LEC has the capacity to metastasize to other organs, including liver, lung, and bone, so that the prognosis is generally poor [5,6]. There have been several reports of thymic carcinoma, including TLEC, there have been few reports on the analysis of TLEC alone, with the only large-scale report being a literature review of 33 case reports by Iezzoni in 1995 [1]; this review has been conducted by accumulating case reports to date
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
