Young women of childbearing age,
more common in white female.
Occurs in women with tuberous
sclerosis, but most LAM patients do not have TS.
Renal angiomyolipomas occur in ~60%
of LAM cases.
Radiographic: reticular pattern 80%
of cases, pneumothorax 30-40%, unilateral or bilateral effusion
10-20%. Later hyperinflation. HRCT, numerous thin-walled cysts,
0.2-2.0 cm in diameter, diffusely throughout the lungs.
Gross: diffuse, bilateral cystic
changes throughout. Lungs are enlarged. Most cysts 0.5-2.0 cm,
some may be up to 10 cm.
Micro: cystic changes and LAM cell
infiltration. LAM cells are typically in small clusters or nests
at the edge of the cysts an along pulmonary lymphatics. In
advanced cases, LAM cells can become so prominent that it is
difficult to identify the normal lung architecture. LAM cells
infiltrate the vascular walls and distal airways, leading to
vascular destruction and microscopic foci of hemosiderosis.
Typical LAM cells are round, oval or spindle-shaped. They grow
in a haphazard arrangement. They have a moderate amount of
eosinophilic cytoplasm. Nuclei have fine chromatin or vesicular
IPX: SMA+, desmin+, vimentin+,
Hyperplasia of interstitial
smooth muscle in honeycomb fibrosis
Lymphangiomatosis: infants or
young children of both genders, proliferation of
endothelial-lined spaces along lymphatic routes.
Lymphagioma: extremely rare,
solid coin lesion.
Prognosis: 8-10 years of median