Morphological analogies of fetal prostate stroma and stromal nodules in BPH

A "reawakening" of ontogenetic processes in the development of BPH is still in debate. Therefore, morphological analogies of fetal prostate stroma and nodular stromal proliferates in BPH were investigated.

Fetal prostates (n = 30; weeks 12-40 of gestation) and stromal nodules of benign prostatic hyperplasia (n = 375 from autopsies, n = 100 from biopsies) were investigated by histo- and immunohistochemistry with special regard to cytoskeletal (alpha-actin, desmin, myosin, and vimentin), neuronal (S-100 protein), neuroendocrine (neuron-specific enolase), leukocytic (CD3, CD20, and CD68) and vascular (CD34, BMA-120, and factor VIII) antigens.

The developing fetal prostate stroma consists of immature mesenchymal cells up to week 17 of gestation, followed by fibroblastic and fibromuscular stromal cells up to week 25 of gestation and predominantly smooth-muscular cells until the end of gestation. Stromal nodules occur as immature mesenchymal, fibroblastic, fibromuscular, and smooth-muscular, suggestive of a maturational process. The fetal prostate stroma and the stromal nodules present, with an increasing degree of maturation, a similar vascular pattern and a similar occurrence of CD3 (T-lymphocytes), CD20 (B-lymphocytes), CD68 (macrophages), S-100, and neuron-specific enolase-positive cells.

The data suggest that ontogenetic processes are recapitulated in the development of stromal nodules in benign prostatic hyperplasia, supporting the idea of a "re-awakening" of fetal processes in BPH.