Increased hyaluronan and CD44 expressions in intravenous leiomyomatosis.

BACKGROUND

To determine the influence of hyaluronan and its receptor CD44 in the angiogenesis and invasiveness of intravenous leiomyomatosis (IVL).

METHODS

Paraffin-embedded sections from four IVL cases and 10 uterine leiomyoma cases were immunohistochemically stained for CD34, CD44, basic fibroblast growth factor (bFGF), vascular endothelial growth factor, and platelet-derived growth factor and assayed for microvessel densities. Hyaluronan was immunostained by biotinylated hyaluronan-binding peptide and the results were clinically correlated.

RESULTS

CD34 labeling showed significantly increased microvessel counts in IVL (156.6+/-3.7), when compared to uterine leiomyomas (61.3+/-27.3; P<0.001). Hyaluronan and its receptor CD44 were prominently expressed in IVL when compared to leiomyomas and associated with an elevation in bFGF expression.

CONCLUSIONS

IVL is a highly vascular neoplasm with elevated microvessel counts. The increase of hyaluronan and CD44 expression in IVL suggests that it is highly angiogenic and has an invasive potential. Elevation of hyaluronan may play a possible role in the pathogenesis of IVL.