Sclerosing thymoma: a case report and literature review

Sclerosing thymoma is an exceedingly rare form of thymoma. Since its first documentation in 1994, we have retrieved only 16 records from PUBMED. All these tumors exhibited a noninvasive growth pattern. A 53-year-old man, presenting only with mild dyspnea, was referred to our hospital owing to a soft tissue mass, measuring 4.3×2.5 cm. Microscopic examination led to a final diagnosis of sclerosing thymoma, unexpectedly invading the left brachiocephalic vein. Adjuvantly, the tumor bed received a radiation dose of 95% PTV 50 Gy with conventional fractionation. No sign of local recurrence appeared on a 2-year follow-up computed tomography (CT) scan. Sclerosing thymoma is a rare type of thymoma, and the pathological manifestations are prominent hyalinization and sclerosis, which make the neoplastic areas not obvious, making the diagnosis of the disease difficult. Previously, the disease was considered non-invasive, which may need to be changed.