Cystic lymphangioma is a benign and usually slow-growing tumor of the lymphatic system that is mainly diagnosed in the first few years of life. The head and neck area are the principal locations, but they may develop in virtually any part of the body. Symptoms depend on the site, but a slowly enlarging mass is frequently encountered. The diagnosis rests on imaging studies such as computed tomography (CT) and magnetic resonance imaging (MRI), whereas a biopsy may be necessary for confirmation.
Described as rare tumors of the lymphatic system, lymphangiomas were initially divided into three main groups based on the size of lymphatic spaces and vessels - capillary (comprised of thin and small lymphatic vessels), cavernous (dilated channels) and cystic, which contains numerous lymphatic spaces with connective tissue and smooth muscles, but without connection to the proximal lymphatics     . The vast majority of lymphangiomas are diagnosed by the age of 2 (presumably due to pathological events during embryogenesis), whereas rare adult cases are mainly related to trauma or infections   . The most common locations are the head and neck area (particularly the posterior triangle), as well as the axilla, constituting 75% and 20% of patients, respectively   . However, virtually any site in the body can be a location of cystic lymphangiomas, including the abdomen (the retroperitoneum and the mesentery of the small bowel are the two main sites, but the pancreas, the spleen, the colon, the liver, and other organs have been described to be involved by lymphangiomas) and the mediastinum     Even though the clinical course is often asymptomatic, a progressively enlarging slow-growing mass is the main sign of cystic lymphangiomas, particularly developing in the cervical region, but many symptoms have been reported depending on the location  . Abdominal cystic lymphangiomas, comprising a small percentage of cases, can present with abdominal pain, nausea, vomiting, and loss of appetite   . Furthermore, descriptions of ascites, bleeding, or rupture of lymphangiomas in the retroperitoneum has been documented, mainly in association with tumor enlargement and subsequent compression of adjacent tissues  .
The diagnosis of cystic lymphangiomas is made through a comprehensive clinical approach and implementation of appropriate imaging studies. With a properly performed physical examination, the physician can identify the key features of a cystic lymphangioma - a fluctuant, soft, and fixated mass that is non-tender on palpation . To confirm the disease, however, imaging studies need to be employed. Ultrasonography may be used as a first-line method, revealing sharply delineated cystic septations  , whereas plain radiography of the chest shows a well-defined homogeneous mass . More advanced imaging studies, CT and MRI, are able to clearly show the cystic lymphangioma and its defining characteristics (water-density appearing septate cysts, either unilocular or multilocular)   . Lymphangiography was mentioned as a useful tool as well for some types of lymphangiomas . Some authors have addressed the beneficiary role of a preoperative biopsy and subsequent microscopic examination, but because of the risk for dissemination of the tumor content, this procedure is often avoided  . Still, a fine-needle aspiration cytology (FNAC) might be used .