Herawi Mehsati, Epstein Jonathan I
Department of Pathology, The Johns Hopkins Medical Institutions, Baltimore, MD 21231, USA.
Am J Surg Pathol. 2007 Jun;31(6):889-94. doi: 10.1097/01.pas.0000213447.16526.7f.
Overexpression of alpha-methylacyl coenzyme A racemase (AMACR) in combination with absence of basal cell markers [ie, p63 and high molecular weight cytokeratin (HMWCK)] is typical of classic acinar prostatic adenocarcinoma. We studied the expression and diagnostic utility of p63/HMWCK/AMACR immunohistochemical cocktail staining in ductal adenocarcinoma and cribriform Gleason pattern 4 acinar prostate cancer and compared it to noncribriform Gleason pattern 4 acinar prostate cancer. One to 4 representative formalin-fixed paraffin-embedded archival tissue blocks from 62 radical prostatectomy specimens harboring prostate cancer of ductal (n=51), cribriform Gleason pattern 4 acinar (n=27), and noncribriform Gleason pattern 4 acinar adenocarcinoma (n=48) were included in this study. Immunohistochemistry was performed using a triple stain of AMACR, p63, and HMWCK. Only staining that was moderate or strong was considered positive. The percentage of staining intensity and the presence of occasional basal cells positive with p63/HMWCK were recorded in each histologic type of prostatic adenocarcinoma. Seventy-seven percent of ductal prostatic adenocarcinoma, 67% of cribriform acinar prostatic carcinoma, and 81% of noncribriform acinar prostatic carcinoma showed positive staining for AMACR. There was no statistically significant difference between AMACR staining among the 3 histologic types, although there was a trend for noncribriform acinar prostatic carcinoma to have greater expression of AMACR than cribriform acinar prostatic carcinoma (P=0.07). Staining was often heterogeneous, varying in staining intensities within the same histologic type of carcinoma. Basal cells were detectable by p63 and HMWCK in a patchy fashion in 31.4% (16/51) of ductal and 29.6% (8/27) of cribriform acinar carcinomas compared with 2.1% (1/48) of noncribriform acinar carcinomas. In summary: (1) the majority of prostatic ductal and cribriform acinar carcinomas strongly expressed AMACR, however, subpopulations of these prostatic carcinoma were either completely negative or only weakly positive; (2) AMACR staining was often heterogeneous in intensity in the same histologic type of tumor, even within the same case; (3) patchy basal cell staining in noncribriform acinar prostatic carcinoma is rare. In contrast, remnants of basal cells identified by p63/HMWCK were seen in a patchy fashion in a significant minority of both ductal and cribriform acinar prostatic adenocarcinoma, which most likely represents intraductal spread of tumor.
α-甲基酰基辅酶A消旋酶（AMACR）过表达且缺乏基底细胞标志物[即p63和高分子量细胞角蛋白（HMWCK）]是经典腺泡状前列腺癌的典型特征。我们研究了p63/HMWCK/AMACR免疫组化鸡尾酒染色在导管腺癌和筛状Gleason 4级腺泡状前列腺癌中的表达及诊断效用，并将其与非筛状Gleason 4级腺泡状前列腺癌进行比较。本研究纳入了62例前列腺癌根治术标本中具有代表性的1至4个福尔马林固定石蜡包埋存档组织块，这些标本包括导管癌（n = 51）、筛状Gleason 4级腺泡癌（n = 27）和非筛状Gleason 4级腺泡腺癌（n = 48）。采用AMACR、p63和HMWCK三联染色进行免疫组化。仅将中度或强染色视为阳性。记录每种组织学类型的前列腺腺癌中染色强度百分比以及偶尔出现的p63/HMWCK阳性基底细胞情况。77%的导管前列腺癌、67%的筛状腺泡前列腺癌和81%的非筛状腺泡前列腺癌AMACR染色呈阳性。这三种组织学类型之间的AMACR染色无统计学显著差异，尽管非筛状腺泡前列腺癌有比筛状腺泡前列腺癌AMACR表达更高的趋势（P = 0.07）。染色通常不均匀，在同一组织学类型的癌内染色强度有所不同。在31.4%（16/51）的导管癌和29.6%（8/27）的筛状腺泡癌中可呈斑片状检测到p63和HMWCK阳性的基底细胞，相比之下，非筛状腺泡癌中仅2.1%（1/48）有这种情况。总之：（1）大多数前列腺导管癌和筛状腺泡癌强烈表达AMACR，然而，这些前列腺癌的亚群要么完全阴性，要么仅弱阳性；（2）AMACR染色在同一组织学类型的肿瘤内强度通常不均匀，即使在同一病例中也是如此；（3）非筛状腺泡前列腺癌中斑片状基底细胞染色罕见。相比之下，在少数导管和筛状腺泡前列腺腺癌中可呈斑片状见到p63/HMWCK识别的基底细胞残余，这很可能代表肿瘤的导管内播散。
