Acute onset of mediastinal cystic lymphangioma in the puerperium.

Lymphangioma is a benign congenital malformation developing from the prenatal lymphatic vessels. Lymphangiomas are typically slow-growing and asymptomatic, but can occur throughout the body; there are few documented cases of either mediastinal or rapid growing lymphangiomas. Here, we report a case of a 27-year-old female who experienced sudden-onset nocturnal dyspnea 1 month after delivery. Ultrasound and computed tomography revealed a cystic tumor (diameter, 8 cm), which posteriorly displaced the superior vena cava and trachea. Ultrasound-guided aspiration was performed and the tumor disappeared on chest X-ray, only to return on subsequent chest X-ray performed the following day. Therefore, thoracoscopic excision of the mediastinal tumor was performed, and pathological diagnosis confirmed mediastinal cystic lymphangioma. In this report, we discuss the rare nature of this case and the treatment of lymphangioma in pregnancy.