Epstein-Barr virus-associated smooth muscle tumor of the lung in a child: a case report and literature review.

BACKGROUND

Pulmonary Epstein-Barr virus-associated smooth muscle tumor (EBV-SMT) is extremely rare in children with congenital immunodeficiency. This case report describes the clinical details of a pediatric pulmonary EBV-SMT case.

CASE PRESENTATION: A 10-year-old boy presented with a three-year history of persistent cough and intermittent fever. Chest computed tomography (CT) revealed multiple nodules in both lungs. Histopathological examination of bronchoscopic excision specimens revealed spindle cell proliferation with a preliminary diagnosis of myofibromatosis, followed by immunohistochemical analysis showing positivity for smooth muscle actin (SMA), Ki-67 (5-8%), and calponin, while in situ hybridization showed diffuse positivity for Epstein-Barr virus-encoded RNA (EBER), confirming the diagnosis of EBV-SMT. Further immunological evaluation revealed suspected underlying immune dysfunction, characterized by persistently low CD4 + T-cell counts. The patient underwent multiple bronchoscopic interventions, including electrosnaring and forceps excision, as well as laser therapy, high-frequency electrocautery, and cryotherapy, to manage the largest pulmonary and intrabronchial lesions. He was also managed with regular intravenous immunoglobulin (IVIG) therapy and close clinical monitoring.

CONCLUSION

Pulmonary EBV-SMT should be considered in pediatric patients with unexplained pulmonary nodules and underlying immunodeficiency. Early diagnosis is essential, and a combination of local tumor control with surgical or bronchoscopic interventions and immunomodulatory therapy may be necessary. However, these treatments may not prevent tumor recurrence and progression, highlighting the challenges in long-term management.