A case of a transient phrenic nerve paralysis after resection of a giant lymphangioma evaluated by dynamic digital radiography.

Background: Lymphangioma is a relatively rare benign congenital malformation composed of dilated cystic lymphatic vessels; however, its occurrence in adults and manifestation as mediastinal lymphangioma are even rarer. In general, the incidence of mediastinal lymphangiomas has been reported to range from 0.01 to 4.5% of all mediastinal tumors. Mediastinal lymphangiomas tend to increase in size and can sometimes stretch the phrenic nerve that are present in the mediastinum, resulting in phrenic nerve palsy. Dynamic digital radiography (DDR) allows for quantitative evaluation over time and has recently been utilized in actual clinical practice. The distance between the apex of the lung and diaphragm can be measured, and the movement of the left and right lungs and diaphragm can be evaluated separately. In this report, we describe a case in which DDR demonstrated the improvement of phrenic nerve palsy.
Case Presentation: A 32-year-old woman with no medical history and no smoking history reported dyspnea on exertion, and abnormalities were noted on chest X-ray. Close examinations revealed thymic, pericardial, bronchogenic, and teratoid cysts, and since they appeared to be growing in size, the patient was referred for surgery. Because the giant cyst prevented visualization of the thoracic cavity, puncture was performed for aspiration. The stretched phrenic nerve was identified in the giant cyst wall and was dissected to avoid damaging it. The cyst wall was detachable and excised without obvious mediastinal invasion. The patient had a good postoperative course and was discharged on postoperative day 5. Dynamic digital radiography on postoperative days 3 and 17 showed movement of the left diaphragm, with improvement over time.
Conclusions: Mediastinal lymphangiomas tend to grow in size and can sometimes stretch the phrenic nerves that are present in the mediastinum, resulting in phrenic nerve palsy. Dynamic digital radiography (DDR) is a modality that can also be evaluated quantitatively and over time and can comprehensively determine improvement in transverse paralysis.
(© 2023. The Author(s).)