A case of spindle cell sarcoma of the lung presenting as a pneumothorax

Abstract

The patient was a 59-year-old male who had no significant medical history. He developed breathing difficulties and was diagnosed as having a spontaneous pneumothorax based on X-ray findings. The chest CT revealed bullae in the apex and S⁶ region of the left lung, and an adjacent small nodule, 8 mm in diameter. A chest tube was placed, and he was discharged. However, the pneumothorax recurred the next month Surgery was done to remove the tumor and bullae. It was found that air was leaking from the bulla in the apex.
On histology, the tumor had a herring bone pattern, mitosis was abundant, and the MIB-1 index was high ; a spindle cell sarcoma was suspected. Further examinations revealed that no other organ was the site of the primary lesion. Based on the immunohistochemistry results, pulmonary blastoma and synovial sarcoma were considered in the differential diagnosis. The fused gene characteristic of synovial sarcoma was not detected. Thus, a definite diagnosis could not be made. During 3 years and 9 months of follow-up, no sarcoma lesions have been identified ; the patient remains recurrence free.