Resection of a rapidly growing chest wall cyst: a case report

When cystic lesions are detected in the chest wall, postoperative seroma and abscesses can be considered in the differential diagnoses. Herein, we present a case of a large chest wall cyst with rapid growth 5 years after thoracic surgery.

A male patient in his 60s was admitted to our hospital complaining of a rapidly enlarging chest wall swelling. He underwent a pleural biopsy for pleural thickening and was diagnosed with pleurisy 5 years ago. Computed tomography revealed a cystic lesion with a capsule measuring 14 cm × 10 cm, and contrast-enhanced magnetic resonance imaging revealed a heterogeneous enhancement effect inside the lesion. Surgical resection was performed for definitive diagnosis and therapeutic purposes. Intraoperatively, a cystic lesion with a thick capsule located outside the thorax was seen. The lesion was resected completely with no remaining adherence to the surrounding tissues and muscles. Histopathological examination revealed that the cyst wall was a non-epithelial fibrous connective tissue with inflammatory cell infiltration, and the contents were viscous liquid and fibrin, suggestive of a chest wall cyst. The cyst wall had abundant CD34-positive vascular endothelium, suggestive of rapid enlargement due to the influx of exudate associated with angiogenesis. No recurrence was observed 1 year postoperatively.

In addition to bacteriology, pathological examination, including immunohistological examination, is useful for the differential diagnosis of chest wall cystic lesions.