It inhibits activation of T cells and B cells by reducing their sensitivity to interleukin-2 (IL-2) through mTOR inhibition. Prognosis
The prognosis for lymphangioma circumscriptum and cavernous lymphangioma is generally excellent. This condition is associated with minor bleeding, recurrent cellulitis, and lymph fluid leakage. Two cases of lymphangiosarcoma arising from lymphangioma circumscriptum have been reported; however, in both of the patients, the preexisting lesion was exposed to extensive radiation therapy.In cystic hygroma, large cysts can cause dysphagia, respiratory problems, and serious infection if they involve the neck. Patients with cystic hygroma should receive cytogenetic analysis to determine if they have chromosomal abnormalities, and parents should receive genetic counseling because this condition can recur in subsequent pregnancies.Complications after surgical removal of cystic hygroma include damage to the structures in the neck, infection, and return of the cystic hygroma. Epidemiology
Lymphangiomas are rare, accounting for 4% of all vascular tumors in children. Although lymphangioma can become  evident at any age, 50% are seen at birth, and 90% of lymphangiomas are  evident by 2 years of age. History
In 1828, Redenbacher first described a lymphangioma lesion. In 1843, Wernher gave the first case report of a cystic hygroma, from the Greek "hygro-" meaning fluid and "oma" meaning tumor. In 1965, Bill and Summer proposed that Cystic hygromas and lymphangiomas are variations of a single entity and that its location determines its classification. References
External links

Cystic hygroma at eMedicine
A hairball is a small collection of hair or fur formed in the stomach of animals, and uncommonly in humans, that is occasionally vomited up when it becomes too big. Hairballs are primarily a tight elongated cylinder of packed fur, but may include bits of other elements such as swallowed food. Animals with hairballs are sometimes mistaken as having other conditions of the stomach such as lymphosarcoma, tuberculosis, and tumor of the spleen. Cats are especially prone to hairball formation since they groom themselves by licking their fur, and thereby ingest it. Rabbits are also prone to hairballs because they groom themselves in the same fashion as cats, but hairballs are especially dangerous for rabbits because they cannot regurgitate them. Due to the fragility of their digestive systems, hairballs in rabbits must be treated immediately or they may cause the animal to stop feeding and ultimately die due to dehydration. Cattle are also known to accumulate hairballs but, as they do not vomit, these are found usually after death and can be quite large. Clinical significance
A trichobezoar is a bezoar (a mass found trapped in the gastrointestinal system) formed from the ingestion of hair. Trichobezoars are often associated with trichotillomania (compulsive hair pulling). Trichobezoars are rare, but can be fatal if undetected. Surgical intervention is often required. Society and culture
Although uncommon in humans, some hairballs have been reported.