Histopathology of lymphangioleiomyomatosis (lung)

(A) Low power view showing cystic air space (arrow) characteristic of lymphangioleiomyomatosis (LAM), which is different to the airspace dilatation typical of emphysema.

(B) High power view demonstrating abnormal smooth muscle cell (LAM cell) clusters surrounding the cysts.

(C) Hematoxylin and eosin staining of LAM lung tissue.

(D) Immunohistochemical staining with smooth muscle cell actin (SMA) demonstrating the presence of abnormal smooth muscle cells (brown stain).