Lymphangioma overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Haytham Allaham, M.D. [2]
Overview
Lymphangioma arises from lymph vessels, which are normally involved in the re-circulation of excess body fluid back into the blood stream. The exact pathogenesis of lymphangioma is not fully understood. It is thought that lymphangioma is caused by either sequestration of lymph tissue, abnormal budding of lymph vessels, lack of fusion with the venous system, or obstruction of lymph vessels. Lymphangiomas most commonly develop at the head and neck regions. Lymphangioma is associated with a number of conditions that include Turner syndrome and Down syndrome. On gross pathology, characteristic findings of lymphangioma include a grey-white, well circumscribed, edematous mass with a variable size and consistency. On microscopic histopathological analysis, characteristic findings of lymphangioma include thin walled endothelial lining, intraluminal accumulation of eosinophilic deposits, and clusters of intraluminal lymphocytes. There are no known direct causes for lymphangioma. Lymphangioma must be differentiated from arteriovenous malformation, branchial cleft cyst, and dermoid cyst. Lymphangiomas are rare, accounting for 4% of all vascular tumors among children. The incidence of lymphangioma is estimated to be less than 2 cases per 100,000 individuals in the United States. Lymphangioma commonly affects individuals younger than 5 years of age. Lymphangioma affects men and women equally. There is no racial predilection to the lymphangioma. CT scan may be diagnostic of lymphangioma. Findings on CT scan suggestive of lymphangioma include a homogeneous, cystic, mass that may demonstrate intrinsic septations and compression of adjacent organs. The mainstay of therapy for lymphangioma is surgery. Treatment for lymphangioma involves the removal of the abnormal tissue; however complete removal may be impossible without removing other normal areas. Most patients need at least two procedures done for the removal process to be achieved.[1][2][3][4]
Pathophysiology
Lymphangioma arises from lymph vessels, which are normally involved in the re-circulation of excess body fluid back into the blood stream. The exact pathogenesis of lymphangioma is not fully understood. It is thought that lymphangioma is caused by either sequestration of lymph tissue, abnormal budding of lymph vessels, lack of fusion with the venous system, or obstruction of lymph vessels. Lymphangiomas most commonly develop at the head and neck regions. Lymphangioma is associated with a number of conditions that include Turner syndrome and Down syndrome. On gross pathology, characteristic findings of lymphangioma include a grey-white, well circumscribed, edematous mass with a variable size and consistency. On microscopic histopathological analysis, characteristic findings of lymphangioma include thin walled endothelial lining, intraluminal accumulation of eosinophilic deposits, and clusters of intraluminal lymphocytes.
According to Whimster, the basic pathologic process is the collection of lymphatic cisterns in the deep subcutaneous plane. These cisterns are separated from the normal network of lymph vessels, but they communicate with the superficial lymph vesicles through vertical, dilated lymph channels.
Whimster postulated that these cisterns might arise from a primitive lymph sac that fails to connect with the rest of the lymphatic system during its embryonic development. A thick coat of muscle fibers that cause rhythmic contractions line these sequestered primitive sacs. Rhythmic contractions increase the intramural pressure, causing dilated channels to protrude from the walls of the cisterns toward the skin. He suggested that the vesicles seen in lymphangioma circumscriptum are outpouchings of these dilated projecting vessels.
Whimster's observations are supported by those of lymphangiographic and radiographic studies. These studies revealed that large multilobulated cisterns extend deep in the dermis and laterally beyond the obvious clinical lesions. These deep lymphangiomas show no evidence of communication with the adjacent normal lymphatics. The cause for the failure of these primitive lymph sacs to connect to the rest of the lymphatic system is not known.
Some lymphangiomas may represent vascular malformations during embryonic development rather than as true neoplasms. [5] Vascular endothelial growth factor (VEGF)–C and VEGF receptor-3 are active in the formation of lymphangiomas. Based upon their expression, superficial lymphangiomas more likely result from peripheral lymphatic dilatation than from a growth factor.
Causes
There are no known direct causes for lymphangioma.
Differentiating Lymphangioma from other Diseases
Lymphangioma must be differentiated from arteriovenous malformation, branchial cleft cyst, and dermoid cyst.
Epidemiology and Demographics
Lymphangiomas are rare, accounting for 4% of all vascular tumors among children. The incidence of lymphangioma is estimated to be less than 2 cases per 100,000 individuals in the United States. Lymphangioma commonly affects individuals younger than 5 years of age. Lymphangioma affects men and women equally. There is no racial predilection to the lymphangioma.
Risk Factors
The most potent risk factor in the development of lymphangioma is the presence of genetic disorders such as Turner syndrome, Down syndrome, and Noonan syndrome.
Natural History, Complications and Prognosis
Most of the patients with lymphangioma will develop a cervico-facial mass that often grows in proportion to the patient’s body growth rate. The mass usually recurs after surgical interventions. Common complications of lymphangioma include esophageal obstruction, upper respiratory tract obstruction, infections, and compression of adjacent tissues such as nerves and blood vessels. Prognosis of lymphangioma is generally excellent.
Diagnosis
History and Symptoms
The majority of patients with lymphangioma are asymptomatic.
Physical Exam
Lymphangioma patients often appear healthy. On physical exam a painless , compressible, soft neck mass that often transilluminates is a diagnostic finding on physical exam.
Laboratory Findings
There are no diagnostic lab findings associated with lymphangioma.
CT Scan
CT scan may be diagnostic of lymphangioma. Findings on CT scan suggestive of lymphangioma include a homogeneous, cystic, mass that may demonstrate intrinsic septations and compression of adjacent organs.
MRI
MRI may be diagnostic of lymphangioma. Findings on MRI suggestive of lymphangioma include hyperintense signal enhancement due to cyst formation.
Other Diagnostic Studies
The definitive diagnosis of lymphangioma is confirmed by a biopsy. Characteristic findings for lymphangioma on microscopic histopathological analysis can be found here.
Treatment
Medical Therapy
There is no medical treatment for lymphangioma; the mainstay of therapy is surgery.
Surgery
The mainstay of therapy for lymphangioma is surgery. Treatment for lymphangioma involves the removal of the abnormal tissue; however complete removal may be impossible without removing other normal areas. Most patients need at least two procedures done for the removal process to be achieved.
References
- ↑ Lymphangioma. Wikipedia (2016) https://en.wikipedia.org/wiki/Lymphangioma Accessed on March 3, 2015
- ↑ Lymphangioma. PathologyOutlines (2016) http://www.pathologyoutlines.com/topic/softtissuelymphangiomacystic.html Accessed on March 5, 2016
- ↑ Lymphangioma. Libre Pathology (2016) http://librepathology.org/wiki/Vascular_tumours#Lymphangioma Accessed on March 5, 2016
- ↑ Lymphangioma. Radiopeadia (2016) http://radiopaedia.org/articles/lymphangioma Accessed on March 5, 2016