Lymphangioleiomyomatosis (LAM) is a rare interstitial lung disease that mostly affects women, and is characterized histologically by the proliferation of atypical smooth muscle cells in the lymphatic system. Radiologically, LAM in the lung parenchyma is characterized by the presence of multiple pulmonary cysts (Fig. 1a). Abdominal findings associated with LAM are less well known, although they have been described in up to 70% of patients. The most common is renal angiomyolipoma (AML), which can appear in 20%–54% of cases. Other findings are lymphangioleiomyomas, lymphadenopathies and chylous ascites.1

Fig. 1.

Radiological findings in the case, characterized by (A) multiple pulmonary cysts, (B) a right renal mass (yellow arrow), and (C) multiple round cystic lesions in the retroperitoneum (yellow arrows) and pelvis.

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To draw attention to these abdominal findings, and to recognize their clinical importance, we present 2 cases of LAM associated with abdominal disease.

The first case is that of a 42-year-old woman who presented clinically with a pneumothorax that required a chest drain. During the same procedure, cysts were removed from the apex of the lung, with a histological diagnosis of LAM cysts. A subsequent chest computed tomography (CT) incidentally detected a right renal mass (Fig. 1b). The mass was exophytic, with homogeneous density, measuring about 4-cm, and did not contain fat. Radiologically, it corresponded to an indeterminate renal mass, but given that the patient had already been diagnosed with LAM, and that fat was not evident within the mass, it was suggested that it could be consistent with an atypical AML. A percutaneous biopsy performed to rule out any other type of renal tumor confirmed that it was indeed an AML. The patient remains asymptomatic as regards the renal mass, and is undergoing checkups.

The second case is that of a 38-year-old woman in whom suspected cancerous ovarian cysts were detected during a gynecological examination. On the abdominal CT for staging and diagnosis, multiple round cystic lesions were observed in the retroperitoneum and pelvis (Fig. 1c). Pulmonary cysts were seen in the lung bases. The patient had no respiratory symptoms. Radiologically, the retroperitoneal and pelvic cysts were consistent with lymphangioleiomyomas, and the finding of cysts in the lung parenchyma confirmed the diagnosis of LAM. In this case, the disease presentation was the abdominal findings.

AMLs are benign tumors that are characterized radiologically by the existence of fat; however, this is absent in 5% of tumors, making them more difficult to diagnose. Treatment is conservative unless complicated by bleeding, which may require surgery or embolization. It has been reported that its association with LAM is so strong that, as in this case, when a renal mass is identified in a patient with LAM, an AML should be suspected.2

Lymphangioleiomyomas are cystic dilations of the lymphatic system that are produced by proliferation of the atypical cells of the LAM. Size may vary depending on gravitational factors or diet, the patient may be asymptomatic or report non-specific abdominal discomfort, and the condition can be confused with other processes such as lymphadenopathies or neoplasia, as in the case presented. There is no effective treatment.

In conclusion, we believe that physicians should be aware of the abdominal symptoms associated with LAM, as these may help diagnose the disease and obviate the need for more aggressive tests. Knowledge of the clinical importance of these findings may also avoid unnecessary surgery. We suggest that abdominal CT scans be performed in cases of chest CT consistent with LAM.