Association of lymphangioleiomyomatosis (LAM) with endosalpingiosis in theretroperitoneal lymph nodes: Report of two cases

We report 2 patients in whom pulmonary lymphangioleiomyomatosis (LAM) affec ted the retroperitoneal lymph nodes and was associated with endosalpingiosi s. These lesions were large, encapsulated masses with multiple cysts contai ning chylous fluid. Both were characterized by proliferating LAM cells that formed fascicles separated by slit-like channels. Some cysts were lined by ciliated epithelium resembling that of Fallopian tubes. Other cysts were l ined either by flattened endothelial cells or by a mixture of these cells a nd epithelial cells. Many LAM cells gave a positive reaction with HMB-45 an tibody. Most LAM cells in fascicles were reactive for a-smooth muscle actin and desmin. In 1 patient, many of the epithelial cells and some of the sub jacent LAM cells were positive for estrogen and progesterone receptors. In conclusion, immunostaining with HMB-45 antibody and markers for smooth musc le cells can be helpful in the evaluation of problems in the differential d iagnosis of lesions of extrapulmonary LAM, particularly those involving the genital system.