2. CYSTIC HYGROMA
-Definition
Cystic hygromas are multiloculated cystic structures that
are benign in nature.
-They form as the result of budding lymphatics and, thus,
may occur anywhere in the body, although they are most
frequently encountered in the neck (75%) and axilla
(20%).
-Cystic hygromas frequently abut and/or encompass
neurovascular structures.
-Surgical excision remains the therapy of choice and
usually is performed shortly after diagnosis.
Pathophysiology:
Lymphatic channels are formed from a series of clefts
that develop in the mesenchyme around the sixth week of
gestation.
-From these channels, sacs are formed that establish
drainage with the venous system.
-Failure to establish venous drainage results in dilated
disorganized lymph channels, which, in the largest form,
present as cystic hygromas.
Mortality/Morbidity:
Airway obstruction
-Is the most critical complication of cystic hygroma
occurring in the neck.
-To assess risk of airway obstruction, carefully evaluate
children with cystic hygromas of the head and neck for
any signs of tracheal deviation and for involvement of the
oropharynx, airway, and pharynx, such as the
hypopharynx and hypolarynx.
- Often the tongue, base of tongue, and supraglottic
larynx are involved when the airway is involved, not just
mediastinal or neck fullness causing tracheal deviation.
Secure the airways in patients with high risk of
obstruction.
Risk of infection
-In a cystic hygroma is approximately 16%. Infection
may result in additional swelling, pain, fever, and
localized erythema.
Risk of hemorrhage
Is approximately 13%. Consider this complication in an
enlarging painful cystic hygroma in a patient with
evidence of acute blood loss.
Age:
Most cystic hygromas are evident at birth (65%), with the
remainder evident by the time the individual is aged 2
years.
Etiology
-Fetal cystic hygromas have almost a 50% association
with chromosomal disorders such as aneuploidy
-Cystic hygroma is strongly associated with Turner
syndrome (predominantly a 45 XO karyotype), trisomy
21 (Down syndrome), trisomy 18 (Edwards syndrome),
and Noonan syndrome.
-Some cystic hygromas can occur in otherwise healthy
fetuses and babies.
Physical:
-The masses are usually large soft structures without
clear margins.
-Physical examination may reveal extension into adjacent
structures (eg, oral cavity).
-Examine neck for tracheal deviation or other evidence of
impending airway obstruction.
-Closely inspect the tongue, oral cavity, hypopharynx,
and larynx because any involvement may lead to airway
obstruction
-At the time of presentation, include physical
examination and chest radiograph with evaluation.
-Chest radiography and/or computed tomography are
necessary to determine whether the mediastinum is
involved
-Ultrasonograpy and Magnetic resonance imaging (MRI)
often is required preoperatively to determine extent of
invasion into adjacent structures and tumor involvement
with neurovascular structures.
DDX
-Hemangiomas
-Lymphangiomas
-Neck tumors
-Anterior cystic hygroma
-Laryngocele
-Posterior encephalocele
-Cervical meningocele or meningomyelocele
-Transient cervical cyst
-Branchial Cleft Cysts
-Encephalocele
-Dermoid cyst
-Sebaceous cyst.
3. Management
Medical Care:
The medical treatment of cystic hygroma includes
injection of sclerosing agents and/or steroids.
-Treat an infection with intravenous antibiotics and
perform definitive surgery once the infection has
resolved.
-However, some infected cystic hygromas may improve
with use of a sclerosing agent, such as OK-432, which
contains penicillin and streptococci.
-Medical therapy with sclerosing agents is an alternative
and should be discussed with the patient.
-Absolute alcohol as a sclerosing agent has been used
with some success in some patients; alcohol works well
in vascular malformations.
-If unresectable lesions are small cysts, they may not
respond to sclerosis.
-Recurrent disease may respond poorly to sclerosis. .
-Medical therapies also are being studied for in utero
application.
-This approach is appealing because it avoids the
difficulties of delivery of a child with a large cystic
hygroma. .
Surgical Care:
-The mainstay of therapy is surgical excision.
-The goal of performing surgical therapy is to remove the
lymphangioma completely or to remove as much
lymphangioma as possible, sparing all vital
neurovascular structures.
-The exceptions include premature infants of small size
and those with involvement of crucial neurovascular
structures that are small and difficult to identify (eg,
facial nerve).
-In such infants, delay surgery until the child is aged 2
years to allow growth of the child to a size that facilitates
surgical excision without increased morbidity
-Many newborns who have cervical hygromas with stable
airways and food ways can be observed, especially
individuals with parotid hygromas.
-Do not attempt drainage of the cyst because it increases
the risk of infection through possible contamination and
causes increased difficulty during resection because the
thin walls of the cyst are not located easily when not fluid
filled.
-Tracheotomy may be necessary to secure the airway
when obstruction is observed.
Complications resulting from excision of a cystic
hygroma include
▪ damage to a neurovascular structure
▪ chylous fistula
▪ chylothorax
▪ hemorrhage.
