前列腺穿刺组织的电镜观察

目的 探讨前列腺癌与良性前列腺增生的超微结构差异,以及中-低分化前列腺癌中前列腺小体和储存空泡的超微结构特征、形成和分泌过程及其病理意义.方法 收集上海交通大学附属第六人民医院2006年6-12月就诊的50例临床高度疑为前列腺癌的病例,在B超引导下穿刺活检时,在最可能是癌的部位加穿一针,戊二醛固定后作超薄切片,电镜下观察.结果 50例穿刺活检中光镜下42例诊断为前列腺癌.31例电镜下见Gleason 3～5级癌细胞.癌细胞巨大的核仁,与间质直接接触,胞质内见微囊,偶见核分裂象,癌周间质中黏液性纤维增生灶形成是与良性前列腺增生主要的区别.31例电镜下见到的癌中29例(93.5%)胞质内有前列腺小体和储存空泡.与良性前列腺分泌细胞一样它们形成于高尔基体,通过顶质分泌或细胞排粒方式分泌到腺腔.结论 电镜有助于鉴别前列腺良恶性上皮细胞.鉴于前列腺小体在中-低分化前列腺癌中的高检出率,它可以成为电镜下鉴别前列腺癌细胞和正常间质细胞以及判断转移性肿瘤前列腺来源的超微结构特征之一.

Electron microscopic examination on 50 cases of prostatic needle biopsies

Objective To study the differences in ultrastructural findings between prostatic carcinoma and benign prostatic hypertrophy, and the various ultrastructural features seen in moderately to poorly differentiated prostatic carcinoma. Methods Utrasound-guided needle biopsies were carried out in 50 clinically suspicious cases of prostatic carcinoma. For each case, one additional core was sampled from the most suspicious area, fixed in glutaraldehyde and examined under electron microscopy. Results In the 50 cases of prostatic needle biopsies studied, there were a total of 42 cases with histologic findings of prostatic carcinoma. Thirty-one cases showed features corresponding to Gleason's score 3 to 5. In contrast to that seen in benign prostatic hypertrophy, the ultrastructural findings of the tumor cells commonly seen in prostatic carcinoma included the centrally located giant nucleoli, a direct contact with stroma, and formation of cytoplasmic microcyst. Occasionaly, there were mitotic figures seen, accompanying with fibromyxoid change of the peritumoural stroma. Amongst the 31 cases of Gleason's score 3 to 5 prostatic carcinoma, 29cases (93. 5%) demonstrated cytoplasmic prostasomes and storage vesicles. Similar to their counterparts in benign prostatic cells, prostasomes and storage vesicles in prostatic carcinoma cells were formed in the Golgi apparatus and released into the lumen by apocrine excretion and exocytosis. Conclusions Electron microscopy is helpful in distinguishing between benign and malignant prostatic lesions. Because of the high yield of prostasomes in moderately to poorly differentiated prostatic carcinoma, prostasomes may become a potential target for cancer immunotherapy and one of the useful diagnostic indices for delineating the prostatic origin of metastatic carcinoma.