[Primary carcinosarcoma of TE lung--a report of two cases]

Carcinosarcoma is a rare lung tumor and accounts for less than 0.3% of primary lung malignancies. Since the first description by Kika in 1908, only 36 cases with this kind of tumor have been appeared in the Japanese literatures by 1993. This report presents our surgical experiences of two cases with carcinosarcoma of the lung confirmed by pathological examination. Case 1: 64-year-old male underwent left lower lobectomy with lymph node resection. The patient has been well 27 months after the operation without tumor recurrence. Case 2: was a 75-year-old male, who underwent left upper lobectomy, partial resection of left lower lobe (S6) with lymph node resection. This patient died of aspiration pneumonia 90 days after successful resection of the tumor. In both patients, resected lung tumors were diagnosed to be true carcinosarcoma by histopathological examinations. True carcinosarcoma is defined to contain both cancelous and sarcomatous elements. Sarcomatous elements may differentiate into rhabdomyosarcoma, osteosarcoma and so on, or they may have non-epithelial elements demonstrated by electron microscopy or immunohistochemical studies. We reviewed the 36 cases with carcinosarcoma of the lung reported in Japanese literatures with special consideration of their histopathological findings. The prognosis of the patients with this rare tumor is also discussed according to the TMN stages.