Cavernous lymphangioma of the vulva

Abstract

Cavernous lymphangioma also known as cystic lymphangioma, cystic hygroma, or lymphangioma cavernosum is a benign tumor characterized by large dilated lymphatic channels with an attenuated endothelial lining which could be in some case surrounded by an irregular discontinuous smooth muscle layer 1. This benign tumor, in the majority of cases described, is either congenital or present in early infancy but is very rare in adulthood 1. Its sites of predilection are the neck and upper trunk 1. In the vulva, to the best of our knowledge, only three cases have been described before 2-4. We report here two additional cases occurring, respectively, in two young white women who presented a history of a gradually expanding vulvar masses. The two patients, respectively, 28-year-old (patient 1) and 19-year-old (patient 2) presented a close clinical consisting on a 1-year (patient 1) and 9 months (patient 2) gradually expanding and painless tumors of the vulva. Physical examination revealed soft and spongy tumors, fluctuant at palpation, each located on the left labium majus and measuring 10 cm for patient 1 and 3 cm for patient 2. Ultrasonography confirmed the cystic nature of the lesions. The routine laboratory investigations and the rest of gynecological and general examinations were normal. Therefore, the lesions were removed operatively with no evidence of recurrence after 9 months (patient 1) and 6 months (patient 2) of follow-up, respectively. Macroscopically, the tumors were similar and multicystic, lobulated, spongy, and relatively well demarcated measuring 13×5×2 cm (patient 1) and 3×2×1 cm (patient 2)(Figure 1a). At the section, the cysts contained a watery fluid. Microscopically, the tumor consisted of dilated lymphatic vessels, often cystic and ectatic, lined by a flattened endothelial lining and containing lymph and/or lymphocytes. The walls of some of the dilated lymphatic spaces contain either a discontinuous smooth muscle layer or a fibrotic interstium with stromal aggregates of lymphocytes and mast cells (Figure 1b). By immunohistochemistry, the endothelium was found to be positive for both FVIII, CD31, and CD34 antibodies and smooth muscle for actin and H-caldesmon. Cytokeratins were negative. (a) Macroscopic aspect of cavernous lymphangioma. Relatively well demarcated, lobulated, cystic tumor. (b) Microscopically, the tumor consists of multiple cystic thin-walled lymphatic spaces irregularly surrounded by a smooth muscle layer. Cavernous lymphangioma is a benign lymphatic proliferation characterized by large and ectatic lymphatic channels. This tumor is encountered in pediatric pathology, particularly in patients with Turner's syndrome or other malformative disease, but it is uncommon in adult and is located in various anatomical sites 1. In the genital tract at the exception of ovaries, cavernous lymphangioma are exceptional and have been described only in uterine corpus (two cases) and in vulva (three cases), where they are located exclusively in labium majus and in young patients less than 30 years of age, without history of radiation therapy or other pathologies 2-5. The symptomatology consists, as in the present case, of gradually expanding painless mass with a size varying from 4 to 13 cm. The main differential diagnosis of this tumor are firstly cavernous hemangioma, but the latter lacks interstitial lymphoid aggregates and smooth muscle layer, secondly lymphangioma circumscriptum which are characterized by subepidermal dilated lymphatic spaces and a clinically vesicular appearance, and lastly multicystic mesothelioma, but the mesothelial lining cells are naturally strongly positive for keratin 1. The etiology of cavernous lymphangioma is regarded as a developmental malformation in which obstruction or agenesis of lymphatic tissue results in lymphangiectasia, secondary to lack of normal communication of the lymphatic system, which are particularly frequent in Turner's and other malformative syndromes 1. Our two patients, as well as all the other previously described patients with vulvar cavernous lymphangiomas, have a normal karyotype, and their general examinations were unremarkable 2-4. The most important complications of cavernous lymphangioma are firstly surinfection and secondly local recurrences due to incomplete surgery. Therefore, in the vulva as in other organs, a complete surgical excision is required but is not always easy, because these tumors are not encapsulated; hence, determining the correct anatomical plane may be difficult.