A Case of Epstein-Barr Virus Associated Smooth Muscle Tumor in the Bronchus of a Child with CARMIL2 Deficiency and a Literature Review.

Abstract

Background: Epstein-Barr virus associated smooth muscle tumors (EBV-SMTs) have been established as a rare neoplasm closely associated with severe immunodeficiency. CARMIL2 deficiency, described in recent years, is a combined immunodeficiency disorder characterized by CD28-mediated T-cell costimulatory defect, altered cytoskeletal dynamics, susceptibility to recurrent infections, and EBV-SMTs. Case report: We report the first documented case of pediatric bronchial EBV-SMTs caused by CARMIL2 deficiency summarizing its clinical features, pathogenesis, key points for diagnosis and treatment. Conclusion: Children with recurrent infections, inflammatory bowel disease, and allergic phenotypes accompanied by NK cell depletion should undergo early genetic evaluation. Routine EBV encoded RNA in situ hybridization (EBER-ISH) is recommended for all smooth muscle tumors, and evidence of primary immunodeficiency (PID) should be investigated in patients without secondary immunodeficiency. Immunorestoration remains the fundamental therapeutic strategy, novel approaches such as exogenous IL-2 require further investigation.