Abstract. Lymphangioleiomyomatosis (LAM) is a progressive disorder of unknown etiology that predominantly affects the lungs, and the resulting respiratory failure can be fatal. Extrapulmonary LAM is a rare disease that often occurs concurrently with pulmonary LAM. Usually, extrapulmonary LAM presents as a localized, well-circumscribed mass. Due to the rare occurrence of extrapulmonary LAM and its atypical location, extrapulmonary LAM is often difficult to diagnose prior to surgery. The present study describes the clinicopathological features of primary liver LAM in a 26-year-old woman. To the best of our knowledge, the present study presents the first case of a primary solitary extrapulmonary form of LAM in the liver.
IntroductionLymphangioleiomyomatosis (LAM) is a progressive disorder that predominantly affects the lungs, and the resulting respiratory failure can be fatal (1). The typical histology of LAM shows a proliferation of smooth muscle arranged in fascicular, trabecular, and papillary patterns associated with slit-like vascular channels (2). Pulmonary LAM can occur sporadically or in association with the inherited hamartoma syndrome tuberous sclerosis (TSC) (3,4).Extrapulmonary LAM is a rare disease that is usually presented as a localized, well-circumscribed mass (5). The primary sites for LAM include the pancreas, retroperitoneum, pelvis, mediastinum, kidney hilus, uterus and mesentery (6). The clinical features of extrapulmonary lymphangioleiomyomatosis are a palpable abdominal mass, abdominal pain, and chylous ascites (7). Differential diagnoses should include lymphoma, schwannoma, paraganglioma at the para-aortic area, and metastatic tumors in the lymph nodes (2). Due to the rare occurrence of extrapulmonary LAM and its atypical location, extrapulmonary LAM is often difficult to diagnose, especially prior to surgery. To the best of our knowledge, the present study reports the first case of primary LAM presenting as a liver mass.
Case reportCase summary. The present study was approved by the Ethics Committee of the Qingdao University Medical College (Qingdao, China). Written informed consent was obtained from the patient's family. In 2009, a 26-year-old woman presented a liver lesion of ~6 cm diameter during a routine examination at Jiaozhou People's Hospital of Qingdao (Qingdao, China). The liver lesion was diagnosed as a liver cyst following a computed tomography (CT) scan of the abdomen. The patient exhibited no clinical symptoms until April 2012. Enhanced abdominal CT scans showed that the mass was located in the left lateral hepatic lobe with 5.7x7 cm enhancement and uneven density (Fig. 1). The radiological differential diagnosis included left lateral hepatic adenoma or focal nodular hyperplasia. Subsequently, a hepatic lobectomy was performed in May, and the patient was discharged after one week.Pathologic findings. Gross examination demonstrated that the liver resection specimen measured 15x10x4 cm. After the specimen was cut longitudinally into 1-cm lobe sections, the liver lobe section exh...