Intrathymic epidermoid cyst – a case report of a rare entity

Abstract

Intrathymic epidermoid cysts are a rare finding, with few reported cases in the literature. The aetiology of these cysts is unknown, though they have been thought to arise from the migration of epidermal tissue to the anterior mediastinum.1 The clinical presentation and imaging findings are non-specific, with diagnosis relying on surgical resection.1 To the best of our knowledge, there have been four other cases of intrathymic epidermoid cysts reported in the literature, including one which developed post blunt trauma to the chest.2 We report a case of a 57-year-old male, who had a longstanding history of chest discomfort. Investigations included a CT scan which revealed a well-circumscribed 52×38×72 mm anterior mediastinal cystic mass. It was removed via a VATS procedure, with histology consistent with a thymic epidermoid cyst. This benign finding should be considered as a rare, but possible, differential for a cystic mass in the anterior mediastinum.