Diagnostic utility of immunohistochemistry in morphologically difficult prostate cancer: review of current literature
ABSTRACT Varma M & Jasani B (2005) Histopathology47, 1-16 Diagnostic utility of immunohistochemistry in morphologically difficult prostate cancer: review of current literatureImmunohistochemistry is widely used to distinguish prostate cancer from benign mimics and to establish the prostatic origin of poorly differentiated carcinoma. We critically review the recent advances in prostate cancer immunohistochemistry, including the introduction of newer basal cell markers such as p63 and the discovery of the overexpression of alpha-methylacyl coenzyme A racemase (AMACR) in prostate cancer. The description of newer urothelial markers to aid the distinction of prostate cancer from urothelial carcinoma is also presented together with refinements in the quality control of PSA and PSAP immunostaining. Although AMACR is a useful immunohistochemical marker for prostate cancer, it has significant limitations. These limitations are discussed and the need for interpreting AMACR immunoreactivity in the appropriate morphological context and in conjunction with basal call markers is emphasized. We also describe the utility of an immunohistochemical panel composed of PSA, PSAP and high molecular weight cytokeratin for distinguishing poorly differentiated prostate cancer from high-grade urothelial carcinoma. A morphological differential diagnosis based selection of immunohistochemical markers is highlighted as a novel approach in the diagnosis of prostate cancer in routine surgical pathology practice.
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ABSTRACT: Alpha-methyl CoA racemase (AMACR), a new molecular marker for prostate cancer, has been recently reported to be one of the most highly expressed genes in papillary renal cell carcinomas (RCCs). We tested the diagnostic usefulness of AMACR antibody in a series of 110 renal tumors: 53 papillary RCCs (33 type 1, 20 type 2); 25 conventional RCCs; 6 chromophobe RCCs; 9 oncocytomas; 5 mucinous tubular and spindle tumors; 2 urothelial carcinomas; 7 angiomyolipomas; and 2 Bellini carcinomas. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded tissue sections, with a primary prediluted rabbit monoclonal anti-AMACR antibody. Both type 1 and type 2 papillary RCCs exhibited cytoplasmic immunoreactivity for AMACR, with diffuse strong granular staining in 96.4% (53/55) of tumors, without correlation with type or nuclear grade. The 5 mucinous, tubular, and spindle cell carcinomas strongly expressed AMACR, and only 5 of 25 clear cell RCCs and 1 of 9 oncocytomas were focally reactive. The remaining 6 chromophobe RCCs, 5 urothelial carcinomas, and Bellini duct carcinomas showed no immunoreactivity for AMACR. Because high expression of AMACR is found in papillary RCCs (type 1 and 2) and in mucinous, tubular, and spindle cell carcinomas of the kidney, immunostaining for AMACR should be used in conjunction with other markers when histological typing of a renal tumor is difficult.Human Pathlogy 07/2006; 37(6):698-703. DOI:10.1016/j.humpath.2006.01.012 · 2.81 Impact Factor
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ABSTRACT: Prostate-specific antigen (PSA) is a 33-kDa serine protease that is secreted by prostatic epithelium and non-prostate tissues. Ectopic expression of PSA has also been reported in a variety of non-prostatic epithelial tumors. Expression of PSA and its clinical implication were examined in a total of 422 cases of primary urothelial carcinoma of the bladder. Cytoplasmic reactivity to PSA was observed in 6 cases (1.4%), with the staining being to a low degree in 3 and a high degree in the remaining 3 cases. Expression of PSA was positively related to multiplicity, large tumors (> or = 3 cm) and muscle invasion (> or = pT2) (p = 0.0008, 0.004 and 0.03, respectively). Patients with tumors of low PSA expression had a better survival than those with tumors of high PSA expression (p = 0.03). Focal expression of PSA can occasionally be detected in some large, invasive urothelial cancer cells. This phenotypic change should be considered in the differential diagnosis of poorly differentiated carcinoma of the lower urinary tract.Anticancer research 01/2008; 28(6B):4149-54. · 1.87 Impact Factor
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ABSTRACT: Prostatic adenocarcinoma and urothelial carcinoma of the urinary bladder are common cancers in men. High grade forms of these tumors may present ambiguous morphologic features that do not permit a definite diagnosis. This distinction between the two tumors has significant staging and therapeutic implications. Hence, an accurate diagnosis is essential for optimal patient care. p63 is a new marker which can be used in this context. It is expressed in most of the urothelial carcinomas and negative in majority of prostatic adenocarcinomas. To compare the expression of p63 in urothelial carcinomas and adenocarcinomas of prostate. Comparative cross--sectional study was carried out at a tertiary cancer hospital from 15 June 2006 to 15 December 2006. Immunohistochemical stain p63 was performed on 50 cases of urothelial carcinoma and 50 prostatic adenocarcinomas. Patients' name, age, histology numbers, grade of tumor, and expression of p63 were recorded. p63 expression was seen in 44 of 50 urothelial carcinomas (88%). None of the prostatic adenocarcinomas expressed p63. The ages of patients with prostatic adenocarcinoma ranged from 49 to 86 years with a median age of 71 years and 41 to 83 years for urothelial carcinomas with a median age of 60.5 years. p63 can be used as a reliable marker to distinguish prostatic adenocarcinomas from urothelial carcinomas in difficult cases in conjunction with other markers like PSA.Indian Journal of Pathology and Microbiology 01/2011; 54(1):59-62. DOI:10.4103/0377-4929.77326 · 0.64 Impact Factor