Treatment
In asymptomatic patients without functional impairment or significant
cosmetic concerns, careful observation is warranted. If treatment is
indicated, options include surgery, sclerotherapy, or medical treatment
with sirolimus; either alone or in combination. Surgical treatment for
LM is most successful in patients with localized malformations that do
not invade important adjacent structures (37), but debulking procedures
for large, complex malformations may be indicated. Surgery could be
offered to the patient above, but sclerotherapy is the most reasonable
approach given high success rates with treatment of macrocytic lesions.
Sclerotherapy is the first line treatment for macrocystic or mixed
micro/macrocystic lesions (64), but is less efficacious for microcystic
LMs (65). In microcystic lesions medical therapy with sirolimus has been
shown to be beneficial in softening the lesions and also decreasing the
size in general, leading to an improved quality of life (66).
Unless symptomatic, sclerotherapy is often not performed until the
patient is at least 6 months of age. Given the location and symptomatic
nature of the patient above, sclerotherapy would be the preferred
treatment course for this patient. For treatment of LMs, a needle is
inserted into the cystic space, lymphatic fluid is drained, and
sclerosing agent is injected. Large cysts may require multiple
injections over 24 to 48 hours, so a pigtail catheter is inserted to
facilitate repeated injections (37,64). Similar to VMs, success of
sclerotherapy is dependent on the sclerosing agent used, dwell time, and
type of LM. Higher rates of cure are seen in macrocystic LMs, as the
entire endothelium can be treated. Doxycycline has the highest success
rates for LM, with a meta-analysis of treated head and neck LM
demonstrating an 80% efficacy rate (34). For lesions in the head and
neck area, which involve the airway, orbit or are close to nerves,
bleomycin, which causes minimal swelling, is the agent of choice (65).
Dose dependent pulmonary toxicity is a potential complication of
bleomycin therapy. Bleomycin doses in sclerotherapy are typically much
smaller than the cumulative dose of 400 mg or greater that is associated
with toxicity (68). Macrocystic LMs respond well to treatment with
OK-432, but microcystic or mixed lesions have a less favorable response
(37). LMs can re-expand over time and require repeated procedures.