"Mesenchymal tumor" or "decidual-like reaction"?

摘要: For more than 40 yr, an unusual urinary bladder lesion has been known to occur in certain strains of mice, but no consensus obtained regarding its etiology, pathogenesis, biology, or classification. The was first assumed be epithelial and non-neoplastic, then it called a smooth muscle cell tumor leiomyosarcoma because ultrastructural characteristics for cells. Later, the nonspecific term "mesenchymal tumor" introduced due histomorphologic differences from all tumors known. Recently, proposal made name "decidual-like reaction" similarity rare spontaneous decidual reaction uterus aging mice. Both lesions are characterized by spindle large pleomorphic epithelioid cells with bizarre nuclei; these mimic anaplasia malignant led pathologists assume neoplastic nature. hypothesis is supported regular presence nuclear progesterone receptors, occasional occurrence eosinophilic cytoplasmic granules, finding morphologically resembling granulated metrial gland (all also observed uterine reaction), reproducibility through long-term feeding combinations estrogens progestogens. It appears that new can explain many detailed facets lesion, exception reported characteristics. controversy versus decidual-like should resolved soon, not only as scientific issue, consequences risk assessment.