[Mesenteric cysts].

INTRODUCTION: Mesenteric cysts and cystic mesenteric tumors are very rare abdominal growths. They may be localized all over the mesentery, from duodenum to rectum, however, they are mostly found in the ileum and right colon mesentery. There are several classifications of these formations, among which the one based on histopathologic features including 6 groups has been most commonly used: 1) cysts of lymphatic origin--lymphatic (hilar cysts) and lymphangiomas; 2) cysts of mesothelial origin--benign or malignant mesothelial cysts; 3) enteric cysts; 4) cysts of urogenital origin; 5) dermoid cysts; and 6) pseudocysts--infectious or traumatic etiology. PATIENTS AND METHODS: Two adult female patients treated at the Department of Surgery, Zabok General Hospital, are presented. The diagnosis of mesenteric cyst was based on explorative laparotomy indicated for a cystic abdominal growth and characteristic palpatory finding, US and CT findings. In both patients, the cysts were successfully treated by total cystectomy. Pathohistologic findings pointed to lymphatic cysts. Control US finding at 3 months postoperatively was normal in both patients. DISCUSSION: Cystic lymphangioma mostly occurs in the first decade of life, with a female predominance. It is usually accompanied by acute abdominal symptomatology. Lymphatic cysts occur later in life (1:100,000 in adults and 1:20,000 in children), also show female predominance, and as a rule are asymptomatic. A mesenteric cyst, especially lymphatic, should be suspected in the presence of painless abdominal tumor, with occasionally painful abdominal pressure, normal laboratory findings, and good general condition in a female patient. In symptomatic cases, acute or chronic abdominal pain is the most common feature, whereas other symptomatology depends on the localization, size and consequential abdominal organ compression (intestinal obstruction, hydronephrosis, lower extremity lymphedema). The term of cystic mesenteric tumor is mostly used to refer to cystic lymphangiomas and lymphatic cysts. In the former, smooth muscle tissue is found, with endothelial lining towards the cavity. The wall of hilar mesenteric cysts does not contain smooth muscle tissue, however, they also show endothelial lining towards the cavity. Exact differentiation between these two entities is necessary for the disease prognosis. Lymphangiomas are prone to recurrence and infiltrating growth. The diagnosis should be made by use of all standard methods of abdominal tumor diagnosis, with ultrasonography (US) and computed tomography (CT), and especially nuclear magnetic resonance providing most information of the growth size and localization. Total cystectomy is the therapeutic method of choice. Open method has been preferred, although reports on successful cystectomy by the laparoscopic method have already appeared in the literature.
CONCLUSION: Intraoperative differentiation between lymphatic cyst and lymphangioma is of utmost importance, and can only be achieved by pathohistologic examination of the cyst wall. If intraoperative biopsy cannot be performed or the finding is uncertain, each cyst should be extirpated in toto due to the above mentioned risk associated with cystic lymphangioma.