SESSION TITLE: Cancer Global Case Reports
SESSION TYPE: Global Case Report
PRESENTED ON: Tuesday, October 28, 2014 at 01:30 PM - 02:30 PM
INTRODUCTION: Fibrosing mediastinitis ( FM ) is a very rare disorder characterised by proliferation of dense fibrous tissue within mediastinum, commonly due to Histoplasmosis in the US. It could also be idiopathic and commonly related to other inflammatory lesions such as retroperitoneal fibrosis. We here report a case of idiopathic FM and retroperitoneal fibrosis proven by biopsy and the patient subsequently was diagnosed adenocarcinoma of lung.
CASE PRESENTATION: A 52-year-old Chinese lady of unremarkable past health presented with cough and chest discomfort. She lived in Hong Kong with no history of residence abroad. Physical examination was unremarkable. CT thorax showed apart from small bilateral pleural effusions, soft tissue encasing esophagus and thoracic aorta extending down to the upper abdominal aorta below the diaphragm.There was no endobronchial or parenchymal lesions seen. Immume markers, tumour markers and Histoplasma antibody were negative. Video-assisted thoracoscopic examination was done and it showed presence of pleural adhesions and thick fibrotic tissue over the posterior mediastinum and peri-aortic areas. Histology of the pleura and soft tissue biopsy revealed fibrocollagenous tissues with no suspicous cells highlighted on immunochemical studies for epithelial and pulmonary markers. There was no evidence for IgG4-associated sclerosing disease either. The histology was compatible with the clinical and radiological diagnosis of FM. She was started on steroid therapy with initial improvement. Because of steroid side effects, azathioprine was added while steroid dosage tailed down. Worsening in condition was noted after about 6 months of treatment. Despite escalating steroid dosage and addition of tamoxifen and colchicine, serial CT scans showed progressive worsening with increase in tissue masses at the mediastinum more marked on the left side encasing pulmonary artery and vein, and subsequent development of pericardial effusion. Clinically, patient complained of progressive breathlessness and chest tightness. With progressive deterioration in condition, she was treated with a course of pulse steroid. At about the same time, a bronchoscopy was done. To one's surprise, it showed infiltrated mucosa at left subcarinal region and biopsy revealed poorly differentiated adenocarcinoma. She was given chemotherapy but response was poor. She finally succumbed about 15 months after initial disease presentation.
DISCUSSION: This was a rare case of FM and retroperitonael fibrosis proven by surgical biopsy of the mediastinal soft tissue. Bronchoscopy was not performed at the initial assessment as all the lesions were mediastinal and pleural in location with no suggestion of endobronchial or parenchymal lesions on initial and subsequent CT scans. However, it was in the later part of the clinical course that adenocarcinoma was diagnosed on bronchoscopy and biopsy. In the medical literature, there were reports of FM mimicking lung cancer but not the reverse, except one reported case of mediastinal recurrence of breast cancer thought to be FM until biopsy revealing the diagnosis. It is extremely unusual for lung cancer to present with FM-like soft tissue masses that encase the aorta and esophagus and extending down to abdomen, and yet the primary remains obscured. And the initial VATS examination and biopsy showed no abnormal cells but fibrosis. We suspect that early endobronchial lung cancer was present when the patient presented with FM and retroperitoneal fibrosis, which actually responded partially to the treatment given. However, with the immunosuppression, the growth of the lung cancer might be uninhibited leading to a rapid disease progression, which was clinically and radiographically hard to be distinguished from disease progression of FM.
CONCLUSIONS: This was the first case of concomitant lung cancer and fibrosing mediastinitis ever reported in medical literature. Giving the very rare occurence of mediastinal and retroperitonal fibrosis, one should be on the alert for any concomitant or associated conditions including neoplasm when evaluating patients presenting with this condition and during its treatment course.
Reference #1: Davis AM, et al.Mediastinal fibrosis. Semin Respir Infect. 2001;16:119-30
Reference #2: Sánchez LN, et al. Mediastinal fibrosis and superior vena cava syndrome. Arch Bronconeumol. 2013; 49:340-2.
Reference #3: Ishibashi H, et al. Mediastinal recurrence of breast cancer suspecting mediastinal fibrosis.Kyobu Geka. 2006; 59:1095-8
DISCLOSURE: The following authors have nothing to disclose: Chi Fong Wong, See Wan Yan
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