Cellular Schwannoma Arising After the Resection of an Anterior Mediastinal Leiomyosarcoma.

Cellular schwannoma is a schwannoma subtype with histopathologic features resembling those of malignant tumors. We report a case of a cellular schwannoma arising at the resection margin of an anterior mediastinal leiomyosarcoma. An 88-year-old woman who had undergone resection of an anterior mediastinal leiomyosarcoma 2 years previously developed a mediastinal tumor at the resection margin, raising suspicion of leiomyosarcoma recurrence. Pathologic analysis after thoracoscopic resection confirmed a cellular schwannoma. This is an extremely rare cellular schwannoma arising in the anterior mediastinum, suggesting that nerve injury from previous surgery may have contributed to its development.