Chapter 96

intrapericardial GCT and cardiac GCT. Intrapericardial GCT
occurs most commonly in infants who are less than 12 months old
and present with findings of cardiac tamponade and congestive
heart failure; as most are benign, they are treated with primary
resection. They can have a very complicated intraoperative course
because they often compress the adjacent atria and ascending aorta.
Cardiac GCTs, which are malignant in 25% of the cases, present
with congestive heart failure and/or arrhythmias (as intraventricular
block) and are most commonly located in the right side
of the heart. They are associated with congenital heart disease
(atrial and ventricular septal defects). Although primary surgical
resection is indicated to avert complete cardiac outflow
obstruction, there are times when the GCT is unresectable, making
cardiac transplantation an option. 24
CHAPTER 96 ■ Thoracic Surgery: Surgical Considerations 1645
Lymphangioma
Although these lesions are also referred to as cystic hygromas, the
more current term is lymphangioma. They have an incidence of
1 in 12,000 births and approximately 50 to 65% of them are present
at birth; the vast majority becomes clinically evident before 2 years
of life. 25 They develop as a result of the failure of primitive
lymphatic buds to form communications with adjacent developing
veins; these buds dilate into lymphatic cysts which subsequently
become lymphangiomas. Anatomically, they are most commonly
found in the neck (75%) and less commonly in the mediastinum
(