Topic review lymphangio-hemangioma Intern 黃維立 2006/03/28

lymphangioma RARE congenital malformation of the lymphatic system Incidence : 5.6% of all benign lesions of infancy + childhood

Male-female ratio: equal Age: Most, about 50%, at birth 80 - 90% by the end of 2nd year

Pathogenesis Failure of drainage from primordial lymph sacs into veins Sequestration of lymphatic tissue with failure to joint central lymphatic channels Abnormal budding of lymph vessels with loss of connection with lymphatic primordia Sequestration隔離

Histology findings These lesions are composed of dilated lymphatic channels with one or two endothelial layers ± an adventitial layer. These dilated lymphatics can vary in size depending on the location and surrounding tissues. ~bases for their classifications.

Four categories

location

Posterior triangle of neck (most common) bordered by the posterior border of the SCM, trapezius, and clavicle Posterior triangle of neck (most common)

Etiolgy Congenital lymphatic malformation! Acquired cause? Traumatic: facial trauma Infectious: Iatrogenic: mediastinoscopy Neoplastic:lymphoma

Clinical manifestation

Clinical manifestation The presence of a mass Small or unnoticed ---- large with mass effect Airway obstruction: dyspnea Problems with feeding: dysphagia Complications: Infection or inflammation of cystic neck structures Spontaneous or traumatic hemorrhage into the cystic structure

How to diagnose? Characteristic appearance Image studies Soft, doughy mass Image studies Ultrasonography CT MRI  more important! 麵團似的 和相鄰structure間的關係，牽涉到之後surgery的考量

Different diagnosis ~ neck mass in infants and children ~ Soft Lipoma Hemangioma Lymphangioma Firm Cyst: thyroglossal, branchial cleft, lingual , thymic Abscess Hematoma Inflammatory lymphadenopathy Neoplastic lymphadenopathy Neoplasia, eg. Fibroma, neuroblastoma Thyroid

MRI findings ~ lymphangioma ~ Low signal intensity on T1WI High signal intensity on T2WI

Management Surgery as the primary management option for all lymphangiomas ~the site of lesion: suprahyoid region ↑recurrence rate, morbidity and complication rate

Management Surgery Aspiration Injection of sclerosing agents Picibanil (OK-432) Diathermy(透熱療法:短波、微波、超音波 ) Radiation

Management Surgery Aspiration Injection of sclerosing agents Diathermy Radiation Observation?!

Observation Spontaneous regression or resolution (10-15%) Selected cases: asympatomatic except for the presence of a mass