Lymphangioma overview

# 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.

# Historical Perspective
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.

# Classification
Lymphangioma may be classified according to  into 3 subtypes, Microcystic type also known as lymphangioma circumscriptum, macrocystic type, also known as cystic hygroma and mixed type. The classification is based on histologic formation.

# 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, intraluminalaccumulation of eosinophilic deposits, and clusters of intraluminal lymphocytes.

# Causes
There are no known direct causes for lymphangioma. Cystic hygroma usually presents in syndromes such as Turner syndrome and Down syndrome. Therefore it is thought that the lymphatic malformations can arise from gene mutations, occuring as missing or deleted part of chromosomes. Acquired lymphangioma circumscriptum occur as a sequele of chronic lymphatic obstruction such as after surgery, infections or radiotherapy.

# 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 patients 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.