Lymphangioleiomyomatosis is a rare disease with proliferation of smooth muscle cells within the lymphatics, mediastinal and retroperitoneal lymph nodes and in the lungs. The clinical symptoms are increasing dyspnea, chylous effusion, intestinal obstruction and thoracic or abdominal pain. The authors report the case of a 42-year-old woman who primarily suffered from thoracic pain, dyspnea and chylous effusion. In further examinations we discovered a leftsided retroperitoneal tumor and a tumor in the mesentery. The diagnostic difficulties experienced are described and the necessity of explorative laparotomy for definite diagnosis is demonstrated. Furthermore, the article provides a review of the latest developments in pathology, diagnostics and therapy.