Case Report
Informed written consent was taken from the patient for the publication. A 53-year old female patient presented to us with a provisional diagnosis of hiatus hernia, which was detected incidentally on a CECT chest and whole abdomen while she was being evaluated for fibroid uterus. Outside, CECT chest and abdomen was reported as hiatus hernia with herniation of omental fat through widened hiatus with heterogeneous lobulated lesion within herniated omental fat; in addition there was significant left pleural effusion with passive atelectasis of the left lung. Patient was asymptomatic from hiatus hernia per se. As the diagnosis was in question, we re-evaluated the CT images with in-house radiologist. On re-evaluation, it appeared to be a large well-defined posterior mediastinal mass approximately 8x8 cm in dimension in left hemithorax in left paraspinal region, abutting on the descending thoracic aorta (DTA) with preserved fat planes (?liposarcoma) (Figure 1A, 1B). The mass showed intense enhancement on contrast imaging (Figure 1C). CT- guided biopsy of the mass was reported on histopathology as possibly inflammatory myofibroblastic tumour. No malignant cells were detected on diagnostic pleural aspiration.
After evaluating resectability of the mass, patient was taken up for excision via left posterolateral thoracotomy. Intra-operatively, a large lobulated mass, approximately 10x10x8 cm in dimension, firm in consistency occupying the paraspinal aspect of left hemithorax was detected. It was adherent to DTA with feeder vessels arising from DTA. The mass was densely adherent to the parieties and to left hemidiaphragm. On intraoperative assessment, it appeared to be a malignant tumour. The mass was gently dissected free from DTA after ligating feeder vessels, necessitating application of partial cross clamp for short duration to control bleeders from DTA. Mass was mobilised from left hemidiaphragm and parieties by combination of blunt and sharp dissection. Approximately 700 ml of straw coloured pleural fluid was aspirated. Left lung was completely normal and away from the mass.
Postoperative period was uneventful and patient was discharged in stable condition on 5th post operative day (POD). The cut section of the operative specimen showed well-defined tumour surrounded by fatty tissue on other end (Figure 2). On HPE of the excised mass, it showed characteristic onion-skin pattern of lymphoid follicles (concentric layer of lymphocytes surrounding an atrophic germinal centre) and was diagnosed as CD, hyaline vascular variant (Figure 3A, 3B).