Review Adult Upper-limb Forearm Cystic Lymphangioma (Cystic Hygroma): A Case Report

Background: Cystic lymphangioma that is the most common type of lymphangioma, but it rarely occurs in the forearm. It may show localized invasive behavior, but is benign. Case presentation: A 42-year-old woman was admitted to the hospital because she had discovered a right forearm mass approximately 3 years earlier.Ultrasound had shown a subcutaneous hypoechoic strip on the right forearm (nature to be determined). Magnetic resonance imaging (MRI) showed characteristics of a lymphangioma with irregular strips, and surrounding irregular small blood vessels showed hypointensity or isointensity relative to the T1-weighted imaging (WI) signals for nearby muscle and hyperintensity on T2WI.Hematoxylin–eosin (H&E) staining showed a dilated cystic space lined with flat endothelial cells, and the cyst wall was rich in mature lymphocytes, smooth muscle, and irregular fatty small cysts.Immunohistochemical (IHC) staining of monoclonal antibody D2-40–labeled cystic lymphangioma endothelial cells was performed and showed focal expression of D2-40. Conclusions: : The atypicality of clinical symptoms and imaging findings makes preoperative diagnosis difficult, so histological examination is necessary for the diagnosis of cystic lymphangioma. At present, if the disease affects the function or appearance of the body, the ideal treatment is radical resection to reduce recurrence. Incomplete resection causes relapse of the disease.