Cervical thoracic duct cyst: a conservative resolution.

A woman in her 70s presented with an enlarging, asymptomatic palpable mass in the left supraclavicular fossa. The clinical impression was of a lipoma. Imaging showed a cystic lesion with continuity of a tubular structure leading to the carotid sheath. Cytology was consistent with thoracic duct sampling. A diagnosis of the rare entity of a thoracic duct cyst with supraclavicular extension was made. This was managed conservatively via repeated aspirations which reduced the size of the mass.