Successful resection of schwannoma from an intercostal nerve causing bloody pleural effusion: report of a case.

We report a case of schwannoma arising from the 9th intercostal nerve, which caused a bloodstained pleural effusion. The patient, a 37-year-old woman, presented with left-sided back pain. A chest X-ray showed left pleural effusion, which was subsequently found to be bloodstained but without malignant cells. Chest magnetic resonance imaging showed a 76-mm tumor arising from the 9th intercostal nerve. The tumor and intercostal nerve were successfully resected. Histological examination revealed that the tumor comprised spindle cells with both Antoni types A and B patterns. There were necrotic changes and cystic degeneration, but no atypical or mitotic cells. Based on these findings, benign schwannoma was diagnosed. Schwannoma is rarely accompanied by bloody pleural effusion, which we assume was caused by partial tumor rupture. Magnetic resonance imaging proved very useful in localizing and characterizing the tumor in this case.