Systemic sclerosis complicated with malignant pleural effusion with high serum CA-125 tumor marker

The malignant pleural effusion in systemic sclerosis (SSc) is an uncommon condition than its common manifestation like interstitial lung fibrosis, pulmonary hypertension, and lung malignancy. We reported here a case of malignant pleural effusion in a 40-year-old female suffering from SSc with high serum tumor marker cancer antigen-125 (CA-125). Computed tomogram guided fine needle aspiration cytology from the lung nodule revealed adenocarcinoma lung. The frequency or reasons of an elevated level of a serum or pleural fluid CA-125 in this case are unclear. Excepting ovarian and lung malignancy, increased CA-125 level in serum, and pleural fluid is also detectable in nonmalignant conditions including SSc as a part of serositis. We emphasized here the malignant potential of SSc and the need for long-term follow-up to detect underlying malignancy. High CA-125 level might be interpreted cautiously.