21. Cystic Hygroma
Definition
Cystic hygroma is a lymph angioma composed of multiloculated, thin-walled cysts. It is typically benign.
Incidence
A rare congenital malformation, cystic hygroma occurs in approximately 1:12,000 births. Because the malformation is congenital, about 65% of the cases are obvious at birth, whereas the remainder manifest themselves within the first 2 years of life.
Etiology
Cystic hygroma occurs as the result of a fetus’s failure during gestation to form venous drainage channels. The result is dilated and disorganized lymph channels. The largest of these lymph channels manifest as cystic hygromas. These cysts are most often found in the neck (approximately 75%) with about 20% being found in the axilla. The remaining 5% may be found virtually any place within the lymphatic system. Because of the proximity of the lymphatic system to the neurovascular bundles, these structures are often encompassed by the cystic hygroma.
Signs and Symptoms
The signs and symptoms vary, depending on the location of the lesion.
• Bluish skin discoloration over the lesion
• Cyanosis
• Soft, painless, doughy/compressible mass
• Stridor
Medical Management
The treatment of choice for cystic hygroma is surgical excision of the hygroma. This is generally undertaken as soon as possible after the diagnosis is made.
Alternatively, sclerosing agents and/or steroids may be directly injected into the cystic hygroma. Sclerosing treatment has had variable success, particularly in view of the young age of the majority of patients with cystic hygroma, possibly as the result of the greater regenerative capabilities of younger patients.
Cystic hygromas are prone to infection. Any infection should be treated with intravenous antibiotics. Any surgical interventions that are scheduled should be postponed until the infection is resolved.
Recurrence is approximately 10%, and is more likely to occur with large cysts in the neck.
Complications
• Airway obstruction
• Deformity of the surrounding bony structures or teeth (if treatment is delayed significantly)
• Hemorrhage
• Infection
Surgical Complications
• Chylothorax
• Chylous fistula
• Hemorrhage
• Neurovascular structural damage
Anesthesia Implications
Because almost all cases of cystic hygroma occur in patients younger than 2 years of age, consideration of age-appropriate measures and developmental anxieties must be addressed. The most obvious implication, particularly in the neonate, is airway obstruction. The large size of the hygroma invades the deep fascia of the neck, oral cavity, tongue, and pharynx. As a result, oral direct laryngoscopy may be difficult, at best, and intubation may prove impossible. Nasal intubation, whether blind or using the fiberoptic bronchoscope, may be the most prudent course of action. Under the best circumstances and when fully awake, the patient with cystic hygroma may have a marginally adequate airway. This airway may be completely lost with mask induction of general anesthesia; therefore, an awake intubation may be the most appropriate intervention, especially in the very youngest patients. Despite these measures, intubation may not be possible and a surgeon must be readily available—in the OR suite—to perform an awake tracheostomy. The tumor may cause tracheal deviation along with other forms of encroachment.
Also, as a result of the tumor, the patient with cystic hygroma may be both malnourished and dehydrated. Despite this, an antisialagogue may be needed to reduce the copious oral secretions. On completion of the surgery and anesthesia, extremely careful consideration must be taken before extubation. It may be prudent to leave this patient intubated because of the great amount of manipulation of the tissues surrounding the airway structures and the high potential for further, continued upper airway edema.
Cystic hygromas are highly vascular and are typically found adjacent to vascular structures. One of the potential complications of surgical excision of a cystic hygroma is hemorrhage. Therefore this surgical procedure is associated with a relatively large volume of blood loss. The anesthetist must concentrate on maintaining normal volume for this patient, particularly if the patient is very young. Because of the patient’s age and the relatively large volumes of fluid that may be administered, temperature shifts are also of great concern. Maintaining normothermia is thus an additional critical concern for the anesthetist.
