Retroperitoneal lymphangiomyomas presenting as a pelvic mass.

Lymphangioleiomyomatosis (LAM) is a rare and devastating disease of unknown etiology that affects women almost exclusively in their reproductive years (1). It mainly involves the lungs, lymphatics, blood vessels and airways. They are usually surrounded by smooth muscle proliferation, leading to cystic lesions and frequently to lung hemosiderosis. The disease causes dyspnea, chylous pleural effusions, pneumothorax, hemoptysis and eventually respiratory failure. The reported prevalence is around one per 1.1 million in the United Kingdom (2), France (3) and the United States (4). To date, less than 100 cases have been reported in the literature (2). Smooth muscle proliferation may also involve extrapulmonary sites, particularly the lymphatic system. Extrapulmonary manifestations, including abdominal and pelvic soft tissue masses along the axial lymphatics, now termed “lymphangiomyomas,” are very few (2). We describe an unusual patient presenting with a primary huge “retroperitoneal lymphangiomyoma” without evidence of pulmonary involvement after follow-up for 11 months. A previously healthy, gravida 3, para 3, 47-year-old woman presented with menses overdue for 3 months, and progressive postprandial right lower abdominal dull pain simultaneously. She did not smoke and had received no oral contraceptives or hormone replacement therapy. Her medical history was unremarkable. After excluding pregnancy, an asymmetrical abdominal girth with a palpable soft mass was noted physically. Pelvic sonography disclosed a multilobulated cystic mass about 18 × 16 × 15 cm3 in size over the abdominopelvic region with minimal fluid accumulation in the cul-de-sac. High-resolution computed tomography (HRCT) revealed a multiple thin-walled, soft-tissue density mass extending from the right caudal pole of the kidney to the pelvic cavity, with displacement of the bowels (Fig. 1). The cysts varied in size, the largest being 7 cm in diameter. Uterine contour was normal and no adnexal mass, renal mass, parenchymal or interstitial pulmonary lesions were noted. CA-125 measured was 24 U/mL. Computed tomography revealed a 18 × 16 × 15 cm3, multicystic, thin-walled, soft-tissue density mass from the right lower pole of the kidney to the pelvic cavity, with displacement of the bowels. The cysts varied in size with the largest measuring 7 cm in diameter. An exploratory laparotomy performed the next day demonstrated somewhat atrophic adnexa and tubes but an undeformed uterus. A multicystic retroperitoneal mass, 18 × 16 × 15 cm3, was found between the mesenteries, spreading from the caudal pole of the right kidney to the pelvis. The uterus and ovaries were separate from the mass and no connection between the mass and genitourinary or gastrointestinal organs was identified. The gross mass appeared yellowish, like a multiple sac aggregation. The mesenteric vessels crossed over the mass, forming a network. On resecting them, white milky chyle leaked from the thin walls. Because of the difficult manipulation, a part of the mass (4 × 4 × 3 cm3) was removed. Histology revealed periendothelial smooth muscle proliferations in the lymphatic channels with positive desmin, factor VIII, actin (muscle-specific actin, Cat. no. Dako M635) immunostaining, all compared to extrapulmonary lymphangiomyomas without evidence of malignancy (2, 3). This tumor contains many lymph- atic channels associated with proliferative smooth muscle cells (hematoxylin–eosin; original magnification × 200). These proliferative smooth muscle cells were confirmed by strong staining for muscle-specific actin (Cat. no. Dako M635) (immunohistochemistry, original magnification × 400). Both estrogen and progesterone receptors were negative for this specimen. The postoperative course was uneventful. The patient resumed menstruation 3 weeks later and was robust after 11 months at the HRCT follow-up. The classic clinical presentation of LAM is distinctive: women of childbearing age present with spontaneous pneumothorax, chylothorax, hemoptysis and slowly progressive dyspnea. The abnormal smooth muscle is found histologically around the airways, blood vessels and lymphatic vessels, leading to an obstruction of airflow (5). There are only four case reports in the literature of patients with LAM presenting with abdominal symptoms 6-9). Two had pulmonary LAM with concomitant pelvic or abdominal lymphangiomyomas at presentation (6, 7), and one was diagnosed at her gestational age of 15 weeks with subsequent successful delivery at 39 weeks (7). The other two had abdominal symptoms at presentation, diagnosed as pulmonary LAM after 3 weeks to 1 year of an initial diagnosis of abdominal or pelvic lymphangiomyomas (8, 9). Our case is the first report of “retroperitoneal lymphangiomyomas” presenting with abdominal symptoms, missed menstrual period without pulmonary invasion. It is also the first report of these lymphangiomyomas without pulmonary invasion in our country. When a retroperitoneal multilobulated cystic mass was found along the pelvic and abdominal lymphatic tracts with no suspicious adnexal or uterine lesions, we should include the rare “lymphangiomyomas” in the differential diagnosis. It is unclear whether purely “extrapulmonary lymphangiomyomas” eventually progress to involve the lung, although early case reports suggest that they can (10). As the average delay in diagnosis of pulmonary LAM is 44 months after the onset of initial manifestation (5), patients should receive an interval HRCT scan in follow-up, as HRCT is a sensitive modality for the diagnosis of early pulmonary LAM, even when the chest X-ray is inconclusive 1-5). LAM is thought to be hormonally dependent and hormonal manipulation in the form of progesterone supplement or antiestrogen methods has been widely used to treat LAM, although the pathophysiology of the disease is still unclear. Progesterone therapy alone or in combination with tamoxifen has yielded variable results, and no definitive conclusions can be drawn from the literature at present (3). Surgical oophorectomy is used to treat LAM although it has often been combined with progesterone and/or tamoxifen (4). Chemical oophorectomy with gonadotropin-releasing hormone agonists has been used to treat LAM (4). For end-stage LAM, lung transplantation can be a valu- able therapy although disease-related complications are frequent (11). As the reported cases are less than 100 in the literature, there been no well-controlled trials to indicate the best management of LAM until now (2). Unfortunately, we did not take the hormone profile of this patient, so the missed menstrual periods initially could be a coincidence of perimenopause or anovulation because menses resumed 3 weeks after inadequate resection of the multicystic mass. It has been suggested that a high level of estrogen during pregnancy, exogenous estrogen intake, oral contraceptive use, or cases with positive estrogen receptors may exacerbate the disease (2). We therefore advised our patient against pregnancy and the use of estrogen. However, in a case report of recurrent retroperitoneal lymphangiomyomas in an 89-year-old white woman after 36 years follow-up without therapy, the authors suggest that the long survival may be related to her menopause (12). As both estrogen and progesterone receptors are negative for our “retroperitoneal lymphangiomyomas” and the patient is potentially near perimenopausal, we suggest a follow-up interval with HRCT of our patient to detect early pulmonary LAM. She is now in a disease-free status at least 11 months after the HRCT follow-up.