Detection of residual tumor cells in bladder biopsy specimens: pitfalls in the interpretation of cytokeratin stains.
ABSTRACT Some patients who have had prior bladder biopsies or transurethral resections undergo a repeat resection within several months for various reasons. The detection of a few residual tumor cells in bladder specimens with prior biopsy site changes can be challenging based on histology alone. Immunohistochemistry for cytokeratins may be used as an adjunct in this situation. We have noted several cases in which keratin stains were performed and positive cells were noted, raising the issue as to whether the cytokeratin positive cells were residual tumor cells or stromal cells. Immunohistochemistry for a panel of antibodies [AE1/AE3, CAM 5.2, high molecular weight cytokeratin, smooth muscle actin (SMA), desmin, and anaplastic lymphoma kinase (ALK)] was performed on 29 cases of bladder biopsies with prior biopsy site changes. Of 29 patients, 25 had a prior history of bladder tumor: 17 had invasive high-grade urothelial carcinoma (T1, 5 cases; T2, 11 cases; T3,1 case); 7 had noninvasive high-grade papillary urothelial carcinoma; 1 had noninvasive low-grade papillary urothelial carcinoma). One of the patients with noninvasive high-grade papillary urothelial carcinoma and one of the patents with invasive high-grade urothelial carcinoma had associated carcinoma in-situ. Four patients had prior benign bladder diagnoses: cystitis cystica et glandularis; polypoid cystitis; follicular cystitis; and neurogenic bladder with benign prostate hyperplasia. Of the 29 cases, 6 (21%) had cells with staining for at least 2 of the cytokeratin markers. Cytokeratin (CK) AE1/ AE3 was positive for cells in 8/29 cases (28%). In 6 of these cases, cells displayed a spindle cell and 2 cases a more epithelioid morphology. CAM 5.2 was positive in cells in 5/29 cases (17%); 3 of the cases had spindle cell and 2 cases epithelioid morphology. High molecular weight cytokeratin was expressed in cells in 2/29 cases (7%) with 1 case having spindle cell and 1 epithelioid morphology. SMA was positive in cells with a spindle cell morphology and negative in the more epitheloid cytokeratin positive cells. Desmin was positive in 3/6 keratin positive spindle cells and negative in keratin positive epithelioid cells. ALK was negative in all the cases. Three cases with spindle cell morphology and positivity for at least 1 of the keratins and SMA stains were interpreted as aberrant keratin expression in myofibroblastic cells based on the staining and the morphology of the spindle cells. Another 3 cases with concurrent staining for at least 1 of the keratins, SMA and desmin were consistent with smooth muscle cells on the basis of their cellular morphology. Another 2 cases had cells, which expressed at least 2 CK markers but did not express SMA, desmin, or ALK and a more epithelioid morphology. These cells were interpreted as residual tumors cells. When interpreting CK stains for the detection of residual tumor cells, one should pay attention to the nature of the cells and not assume all CK staining cells are residual tumor cells.
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ABSTRACT: Metastases are sometimes the first revelation of urologic cancers. The role of the pathologist in case metastatic disease of unknown origin is to affirm the malignant character of the lesion; provide histological information for possible origins; and to give histological therapeutic arguments. In most of the cases the histological analysis based on cellular morphology is sufficient to suspect a particular origin. In case of poor differentiated carcinoma in addition to the histological analysis, the immunohistochemical study allows the detection of various specific antigens. In this review we approach the various morphological criteria and the interest of the various antibodies to confirm the urologic origin of a metastasis.Progrès en Urologie 11/2008; 18. DOI:10.1016/S1166-7087(08)74541-X · 0.77 Impact Factor
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ABSTRACT: The bladder working group of the 2013 International Society of Urologic Pathology (ISUP) Conference on Best Practices Recommendation in the Application of Immunohistochemistry (IHC) in Urologic Pathology discussed 5 settings in which IHC is commonly used in clinical practice. With regard to markers for urothelial differentiation, the committee found that there is no ideal marker or established panel to confirm urothelial differentiation. On the basis of the differential diagnostic consideration, positivity for GATA3, CK20, p63, and either high-molecular weight cytokeratin (HMWCK) or cytokeratin (CK)5/6 is of value in proving urothelial differentiation in the appropriate morphologic and clinical context. With regard to the role of IHC in the distinction of reactive atypia from urothelial carcinoma in situ, the committee recommended that morphology remains the gold standard in this differential diagnosis and that, at best, the IHC panel of CK20/p53/CD44(s) has potential utility but is variably used and has limitations. The immunostaining pattern must be interpreted with strict morphologic correlation, because overreliance on IHC may be misleading, particularly in the posttreatment setting. IHC has no role in the distinction of dysplasia versus carcinoma in situ and in the grading of papillary urothelial carcinoma. IHC may have a limited but distinct role in staging of bladder cancer. In a subset of cases, depending on the clinical and histologic context, broad-spectrum cytokeratins (to identify early or obscured invasion) and desmin (distinction of muscle from desmoplasia and to highlight muscle contours for subclassification) may be helpful. Limited experience and conflicting data preclude smoothelin or vimentin to be recommended routinely for subclassifying muscle type at this time. In the workup of a spindled cell proliferation of the bladder and in limited specimens, we recommend an immunohistochemical panel of 6 markers including ALK1, SMA, desmin, cytokeratin (AE1/AE3), and p63 with either of HMWCK or CK5/6. Currently, there are no prognostic immunohistochemical or molecular studies that are recommended to be routinely performed on biopsy or resection specimens.American Journal of Surgical Pathology 08/2014; 38(8):e20-e34. DOI:10.1097/PAS.0000000000000240 · 4.59 Impact Factor
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ABSTRACT: CONTEXT: Pathology standards for the diagnosis of bladder cancer (BCa) have recently evolved to better reflect patient diagnosis and clinical outcomes. OBJECTIVE: To update pathology reporting standards for BCa. EVIDENCE ACQUISITION: We searched the international medical literature and reviewed all articles that addressed BCa gross dissection, pathologic diagnosis, staging, and reporting as of June 6, 2012. We also reviewed the proceedings from the recent Second International Consultation on Bladder Cancer (Vienna, Austria). The literature selected for review focuses on evidence-based studies that address histopathologic factors in BCa, with emphasis placed on factors that influence patient diagnosis and clinical outcomes. EVIDENCE SYNTHESIS: We separated data into three main components for analysis based on the type of specimen obtained: (1) transurethral resection specimens, with an emphasis on pathologic staging, variants of urothelial carcinoma, angiolymphatic invasion, and relevant ancillary techniques such as immunohistochemistry in assessing these features; (2) cystectomy specimens, with an emphasis on pT0 disease, prostatic involvement by urothelial carcinoma and lymph node dissection and analysis; and (3) cytology correlates, with recommendations for the use of cytology paired with tissue-based sampling. Areas of controversy are described and recommendations based on existing guidelines are provided. The value of a multidisciplinary team is highlighted. CONCLUSIONS: Ongoing international collaborations amongst pathologists have led to emerging standards in the reporting and microscopic diagnosis of BCa specimens. Although some areas remain controversial, we present the most up-to-date data and guidelines relevant to neoplastic pathology of the urinary bladder.European Urology 10/2012; 63(2). DOI:10.1016/j.eururo.2012.10.008 · 12.48 Impact Factor