Case report: Spontaneous regression of a supraclavicular thoracic duct cyst: case report with a follow-up of 25 years.

This article is a follow-up of a previously reported case of a thoracic duct cyst. In 1982, a left supraclavicular swelling appeared spontaneously in a 55-year-old man. The mass was located near the lower part of the sternocleidomastoid muscle. Fine-needle puncture yielded chylous fluid. Radiography of the thoracic duct following direct puncture and injection of contrast medium revealed cystic dilatation of the upper part in close proximity to the jugular and subclavicular veins, with widening of the adjacent intrathoracic duct. Surgery was considered but was not performed as the patient had no symptoms. Radiological re-examination in 1991 showed progression in the size of the cystic expansion but, as the patient was still without complaints, no treatment was given. In 1995 (after 13 years), the patient noted that the cyst had diminished spontaneously. Follow-up MR and clinical examination in 2007, 25 years after the first appearance, showed complete regression of both the cervical cystic dilatation and the widened intrathoracic duct. Thus, spontaneous regression of a cystic dilatation of the thoracic duct can occur.