原发性前列腺黏液腺癌3例临床病理观察

Primary mucinous adenocarcinoma of the prostate:a clinicopathologic analysis of three cases

目的探讨原发性前列腺黏液腺癌的临床病理特征、诊断与鉴别诊断。方法分析3例原发性前列腺黏液腺癌的临床表现、病理形态学特征、免疫组化及组织化学染色特点,并复习相关文献。结果 3例患者临床表现均为排尿困难或膀胱刺激症状,2例血PSA升高,1例正常。大体前列腺切面呈海绵状,2例见胶冻样结节,1例未见明确结节。镜下肿瘤组织主要由蓝染的黏液湖及少量异型上皮细胞团组成,上皮细胞巢呈筛状、腺管状或实性团状漂浮于黏液湖中;3例均合并少量经典型前列腺腺泡癌成分。免疫组化:瘤细胞PSA、CK7和CK19均弥漫强(+),CK20灶性(+),CA125、CEA和CDX-2(-)。AB/PAS染色显示黏液主要位于细胞外,极少数细胞可见细胞内黏液。术后给予化疗或放疗,随访时间分别为6、46个月及10年,未见复发及转移。结论原发性前列腺黏液腺癌是前列腺癌中少见的组织学亚型,确诊时需要与转移性黏液腺癌鉴别,免疫组化可以协助诊断。

Objective To study the clinicopathotogic features, diagnosis and differential diagnosis of primary mucinous adenocarcinoma of the prostate. Methods Three cases of primary mucinous adenocarcinoma of the prostate were investigated by clinical findings, histopathology and immunohistochemistry, and related literatures were also reviewed. Results The three cases presented with dysuria or bladder irritation. The serum prostate-specific antigen （PSA） levels were elevated in 2 cases, and normal in 1 case. Grossly, the prostate showed a spongy cut surface with gelatinous nodules in 2 cases, but without discrete nodule in 1 case. Microscopic examination revealed that the tumor was mainly composed of mucinous lakes and a few of tumor ceils. Clusters of small tubules and cords of epithelial ceils floated within the mucus, with conventional prostatic adenocarcinoma in different proportions. Immunohistochemically, the tumor cells were diffusely positive for PSA, CK7 and CK19, focally positive for CK20, but negative for CA125, CEA and CDX-2. Periodic acid Schiff （PAS） staining revealed pink colored extracellular mucus and few intracellular mucus. Treated with chemotherapy or radiotherapy, the three patients had remained free of locally recurrent or metastatic disease through 6 months, 46 months and 10 years of follow-up, respectively. Conclusions Primary mucinous adenocarcinoma of the prostate is a very rare subtype of prostate adenocarcinoma. It should be differentiated from secondary mucinous adenocarcinoma of adjacent organ. Immunohistochemical studies can confirm the diagnosis. The patients treated by radical prostatectomy and hormonal therapy may have a better prognosis.