Abstract
INTRODUCTION AND SIGNIFICANCE: Congenital Infantile Fibrosarcoma (CIFS) is an exceptionally rare pediatric malignancy, representing approximately 10 % of all soft tissue cancers in young children. Its clinical manifestations vary according to tumor location. When tumors occur in unusual anatomical sites, symptoms may be misleading and delay proper diagnosis and treatment. CASE PRESENTATION: We report an 11-month-old male with a month-long persistent dry cough and high fever unresponsive to antibiotics. Chest CT revealed a pleural mass with mild effusion. Thoracotomy achieved complete excision (R0). Histopathology showed low-grade fibrosarcoma; immunohistochemistry was positive for Vimentin and SMA, focally CD34, and negative for S100, Desmin, and Myogenin, with low Ki-67 (<3 %). ETV6-NTRK3 fusion testing was unavailable. The patient received six cycles of adjuvant VAC chemotherapy and tolerated treatment well, with only mild transient neutropenia. CLINICAL DISCUSSION: Diagnosis depends on histopathological and immunohistochemical analysis, as CIFS mimics several other soft tissue sarcomas. Our review of medical literature found no prior cases of CIFS originating in the pleura, underlining the uniqueness of this case. Management followed a standard multidisciplinary approach consisting of complete surgical excision and adjuvant chemotherapy (VAC protocol). At 12-month follow-up, the patient remained recurrence-free. CONCLUSION: Persistent pneumonia-like symptoms unresponsive to standard treatment in infants should prompt consideration of underlying malignancy. Early recognition and prompt management are essential for improving outcomes in such rare presentations.