假增生型前列腺癌的病理学特征

目的探讨假增生型前列腺癌（PHPA）的临床病理特征及其发生率和生物学行为。方法复查上海交通大学附属第六人民医院2005年1月1日-2006年12月31日860例直肠B超引导下前列腺穿刺活检和46例前列腺癌根治手术切片,对疑有PHPA组织作34βE12（或CK5／6）、p63和AMACR单项免疫组织化学标记（EnVision法）和34βE12／p63／AMACR鸡尾酒抗体双重免疫组织化学标记,将在1个组织块中PHPA占该组织块中癌总量的面积百分比〉60％的病例归入本组,并作病理学分析。结果PHPA在穿刺活检和前列腺癌根治标本中的发生率分别为7．0％和15．2％。66．7％的PHPA与普通型前列腺癌直接移行,76．7％在其他组织块中有普通型癌。PHPA占穿刺活检中癌总量的比例为5％～100％,占根治标本中癌总量的比例为1％～30％。PHPA以大中腺泡增生为主,癌细胞分化较好,排列有极性,腔内常有残存淀粉样小体,低倍镜下类似良性前列腺增生。但腺泡排列紧密,腔内有嗜酸性结晶体和颗粒状无定形物质,核增大,有大核仁,免疫标记AMACR阳性,基底细胞标记阴性,在20项提示恶性的形态学指标中10项出现几率966．7％。PHPA虽然分化较好,但66．7％的PHPA有间质浸润,6．7％有神经浸润,3．3％有腺外浸润,3．3％发生骨转移,肿瘤分布部位周围带多于移行带。结论PHPA的实际发生率不低,绝大多数与普通型癌并存,由于形态学类似良性,肿瘤细胞量又不占多数,因此在诊断中容易被忽视,PHPA高分化前列腺癌不同,应属于Gleason3级的中分化腺癌。

Pathologic characteristics of pseudohyperplastic prostatic adenocarcinoma

OBJECTIVE: To study the clinicopathologic features of 30 cases of pseudohyperplastic prostatic adenocarcinoma (PHPA). METHODS: Eight hundred and sixty cases of ultrasound-guided prostatic needle biopsy and 46 cases of radical prostatectomy specimens collected during the period from January 1, 2005 to December 31, 2006 were retrieved from the archival files. The incidence, morphology, pathologic differential diagnosis, tumor volume, preferred location and Gleason's score were studied. The tissue sections suspicious for PHPA were immunohistochemically stained with high-molecular weight cytokeratin (34betaE12) or CK5/6, p63, AMACR, and cocktail antibody of 34betaE12/p63/AMACR. Cases with PHPA component more than 60% in at least one single slide were selected and pathologically analyzed. RESULTS: PHPA was present in 7% of needle biopsy and 15.2% of prostatectomy specimens. Histologically, 66.7% of PHPA demonstrated direct transition with conventional acinar adenocarcinoma; and 76.7% of cases had coexisting conventional acinar adenocarcinoma in the remaining tissue blocks. The tumor volume accounted for 5% to 100% of total carcinoma among core needle biopsy and 1% to 30% of total carcinoma among radical prostatectomy. PHPA resembled benign prostate glands, in which the hyperplastic malignant acini were predominantly of medium to large size. The neoplastic cells were well-differentiated, with basally located nuclei and luminal corpora amylacea. However, amongst the 20 pathologic indices of prostatic malignancy studied, occurrence of 10 or more indices exceeded 66.7%. Although PHPA looked benign morphologically, 66.7% cases had stromal invasion, 6.7% had perineural invasion and 3.3% had bone metastasis. The tumor was primarily located in the peripheral zone. CONCLUSIONS: PHPA is not a rare phenomenon in prostatic adenocarcinoma. Majority of cases have concurrent conventional acinar adenocarcinoma. It is different from well-differentiated (with Gleason's score 1 or 2) adenocarcinoma with a relatively indolent clinical course. In contrast, PHPA corresponds to moderately differentiated adenocarcinoma with Gleason's score of 3.