EBV-associated myoid tumor with lipoblast-like cells in a patient with normal immunity.

EBV-associated myoid tumor (EBVMT) comprises a specific group of soft tissue tumors with divergent histologic appearances, which typically occur in immunocompromised patients. To the best of our knowledge, there have been no previous reported of EBVMT in patients with normal immunity. EBVMT with lipoblast-like cells (EBVMT-LIC) is an extremely rare variant of EBVMT. Here, a male patient with normal immunity and EBVMT-LIC is presented. Comprehensive EBV latency expression pattern and tumorigenesis molecular analyses are performed to detail the pathologic features of this disease. Our patient was a 14-year-old who suffered from Burkitt's lymphoma 6 years ago and got complete remission for 5 years. At his last visit, he presented with pain and weakness in arms and legs. Subsequent MRI revealed an extramedullary mass at the cervical areas. CT-guided resection was then performed and comprehensive histopathologic examination was conducted. We found a haemangiopericytoma-like pattern with EBER-positive lipoblasts exist in this neoplasm and these features were in accordance with the diagnosis of EBVMT-LIC. Also, the EBV type I latency pattern was observed and the activation of Akt/mTOR pathway and Bcl-2 overexpression were found to be involved in the tumorigenesis of EBVMT-LIC. In conclusion, the results of this study suggest that EBVMT can occur in patients with normal immunity. EBV could achieve a latency type I pattern and may promote the development of EBVMT by activation of Akt/mTOR pathway and Bcl-2 overexpression. The role of chronic latent EBV infection in the development of EBVMT may be more important than previously thought.