A previously healthy 14-year-old boy was admitted to the hospital with a 1-month history of dyspnea and chest pain. A computed tomographic (CT) scan (Fig. 1A) of the chest revealed a mass measuring 16×14×9.8cm in the left thoracic cavity. The mass was heterogeneous with hypodense areas, amorphous calcifications and the erosion of the abutting rib.
(A) Chest CT showed the heterogeneous mass in the left thoracic cavity. The hyperdense areas are calcification and irregular ossification. Several non-enhanced hypodense areas considered to be necrosis or hemorrhage. (B) Histopathology confirmed the diagnosis of mesenchymal chondrosarcoma (H&E ×200).
The patient received the thoracotomy and the mass was removed successfully. It was originated from the left 5th rib. Histopathology diagnosis was mesenchymal chondrosarcoma (Fig. 1B H&E ×200). The patient recovered well after the surgery and refused to receive chemotherapy. He was discharged 14 days after operation.
Mesenchymal chondrosarcoma is a rare malignant tumor originated from bone or soft tissue, which primarily occurred in adolescents and young adults. The biological behavior is malignant and its prognosis is poor. It should be considered when radiologic findings in a young adult are a rapidly growing, heterogeneous mass with hypodense areas and amorphous calcifications. The differential diagnosis for a big thoracic wall mass in a teenager may include other small round blue cell tumors such as primitive neuroectodermal tumor (PNET), Astkin tumor and various soft tissue sarcomata with calcification.1
FundingThis work is supported by grant 2015Y182 and 2016ZDX053 from Scientific Research Fund Project of Yunnan Provincial Education Department.
