Iczkowski K A, Shanks J H, Bostwick D G
Department of Pathology, Mayo Clinic, Rochester, Minnesota, USA.
Histopathology. 1998 Apr;32(4):322-7. doi: 10.1046/j.1365-2559.1998.00398.x.
Small cell carcinoma of the urinary bladder has a more aggressive biological potential than urothelial carcinoma, but its morphology may overlap with poorly differentiated urothelial carcinoma. The CD44 family of glycoproteins mediates cell-cell and cell-matrix adhesion. Aberrant regulation of expression of CD44, and particularly its v6 variant exon, has been correlated with aggressive or metastatic phenotype of some cancers. We measured the degree of protein expression of CD44v6 in small cell and urothelial bladder carcinoma.
Immunohistochemical staining was performed with monoclonal antibodies against CD44v6. Immunoreactivity was absent in 25 of 27 cases of small cell carcinoma, with two showing only weak staining of fewer than 10% of cells. In contrast, all 12 cases of moderately or poorly differentiated urothelial carcinoma displayed moderately intense reactivity in 50% to 100% of cells.
CD44v6 immunostaining discriminates cases of poorly differentiated urothelial carcinoma from small cell carcinoma. It also highlights the presence of mixed small cell urothelial differentiation when present.
膀胱小细胞癌比尿路上皮癌具有更强的生物学侵袭性，但其形态可能与低分化尿路上皮癌重叠。CD44糖蛋白家族介导细胞间和细胞与基质的黏附。CD44表达的异常调控，尤其是其v6可变外显子，与某些癌症的侵袭性或转移表型相关。我们检测了膀胱小细胞癌和尿路上皮癌中CD44v6蛋白的表达程度。
用抗CD44v6单克隆抗体进行免疫组化染色。27例小细胞癌中有25例无免疫反应性，2例仅有不到10%的细胞呈弱阳性染色。相比之下，12例中分化或低分化尿路上皮癌病例中，50%至100%的细胞呈中度强免疫反应性。
CD44v6免疫染色可区分低分化尿路上皮癌和小细胞癌病例。它还能突出存在混合性小细胞尿路上皮分化的情况。
