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  Anatomic Abstracts

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March 2002

A marker for renal cell carcinoma
An immunohistochemical marker for distinguishing among the different subtypes of renal cell carcinoma and separating metastatic renal cell carcinoma from its mimics would be useful in difficult cases. The authors tested the diagnostic use of the monoclonal antibody renal cell carcinoma marker (RCC Ma) against a normal proximal tubular brush border antigen. They performed immunostaining using RCC Ma and the avidin-biotin-peroxidase complex technique on archival tissues from primary and metastatic tumors of renal and nonrenal origin. RCC Ma stained 67 percent (42 of 63) of metastatic renal cell carcinomas and only two percent (two of 108) of nonrenal metastases, both of which were metastatic breast carcinomas. RCC Ma also marked 15 of 146 nonrenal primary tumors. Among the 15 positive cases were tumors from the breast, thyroid, and testis. Notable nonstaining tumors included adrenal (zero of 13), lung (zero of four), and liver (zero of 21) primaries. Among primary renal tumors, 79.7 percent (122 of 153) were positive, including clear cell (84 percent), papillary (96 percent), chromophobe (45 percent), and sarcomatoid (25 percent). Collecting duct carcinoma (zero of five) and oncocytoma (zero of 15) were negative. Interestingly, 72 percent of primary renal cell carcinomas had more than 50 percent of positive tumor cells, in contrast to only 57 percent of metastatic renal cell carcinomas. The authors stated that RCC Ma is an excellent marker for primary renal cell carcinoma. And although RCC Ma is highly specific for metastatic renal cell carcinoma, a negative result may not rule out metastatic renal cell carcinoma because of low sensitivity and a focal staining pattern in some positive cases.

McGregor DK, Khurana KK, Cao C, et al. Diagnosing primary and metastatic renal cell carcinoma: the use of the monoclonal antibody “renal cell carcinoma marker”. Am J Surg Pathol. 2001;25:1485-1492.

Reprints: Dr. Luan D. Truong, Dept. of Pathology, MS 205, Methodist Hospital, 6565 Fannin St., Houston, TX 77030; ltruong@bcm.tmc.edu

Comparison of techniques to detect cervical neoplasia
The cost-effectiveness of different methods for screening for clinically significant cervical disease varies. The authors compared several methods for cervical cancer screening in a study involving 1,997 women between the ages of 35 and 45 from rural Shanxi Province, China. Each woman underwent a self-test for intermediate/high-risk human papillomavirus, a direct test for HPV, fluorescence spectroscopy, liquid-based Pap (read manually and by computer), visual inspection diagnosis, and colposcopy with multiple cervical biopsies. The sensitivity and specificity for the detection of >CIN II were 83 percent and 86 percent, respectively, for the HPV self-test, 95 percent and 85 percent for the HPV direct test, 94 percent and 78 percent for the ThinPrep Pap (>ASCUS), 77 percent and 98 percent for the ThinPrep Pap (>HGSIL), 94 percent and nine percent for fluorescence spectroscopy, 71 percent and 74 percent for visual inspection, and 81 percent and 77 percent for colposcopy. The authors concluded that, based on these data and the existing health care infrastructure in China, further refinement of primary HPV screening using centralized labs is necessary. Self-testing may be effective in local villages if the devices and techniques employed are improved.

Belinson J, Qiao YL, Pretorius R, et al. Shanxi Province cervical cancer screening study: a cross-sectional comparative trial of multiple techniques to detect cervical neoplasia. Gynecol Oncol. 2001;83:439-444.

Reprints: Dr. J. Belinson, Cleveland Clinic Foundation, 9500 Euclid Ave., A-81, Cleveland, OH 44195; belinsj@ccf.org

Predicting behavior of gastric MALT lymphoma
The natural history of low-grade marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) of the stomach is variable. Approximately half of patients respond to antibiotic therapy for Helicobacter pylori. Among those who do not respond to antibiotics are some patients with stable disease which does not progress beyond the indolent low-grade stage. A second group, however, progresses to more aggressive large-cell lymphoma. The ability to predict which patient with persistent disease is likely to have a tumor that behaves in an aggressive fashion has obvious clinical implications. The authors employed microsatellite screening in 24 gastric MALT lymphomas. This was compared with similar analyses in cases of diffuse large B-cell lymphoma of the stomach. Of the 10 cases that showed a t(11;18) translocation, only one showed the presence of other genetic alterations, and none demonstrated transformation to large-cell lymphoma. In contrast, the t(11;18)-negative lymphomas showed numerous allelic imbalances—some of them identical with aberrations seen in high-grade diffuse large B-cell lymphoma (DLBCL)—suggesting that this group is the source of tumors eventually transforming into high-grade DLBCL. The most common of these abnormalities was amplification of 3q26.2-27, which harbors the locus of the BCL6 gene.

Starostik P, Patzner J, Greiner A, et al. Gastric marginal zone B-cell lymphomas of MALT type develop along two distinct pathogenetic pathways. Blood. 2002;99:3-9.

Reprints: Petr Starostik, Institute of Pathology, Wurzburg University, Luitpoldkrankenhaus, Josef-Strasse 2, D-97080 Wurzburg, Germany; petr.starostik@mail.uni-wuerzburg.de

Ovarian mucinous carcinoid tumors
One rarely encounters a primary ovarian mucinous (goblet cell) carcinoid tumor. The clinicopathologic features of a series of these tumors has not been previously described. In this study, the authors presented 17 examples of primary ovarian mucinous carcinoids from patients aged 14 to 74 years (tumor size, 0.8 to 30 cm), excluding cases with minor foci seen in other types of primary ovarian tumors. None of these were associated with the carcinoid syndrome. All tumors were positive, in varying proportions, for one or more neuroendocrine markers. In six cases, the tumor was located in the wall of a mature cystic teratoma. Other associated primary ovarian neoplasms were mucinous cystadenocarcinoma (three of 17), mucinous cystic borderline tumor (one of 17), borderline Brenner tumor (one of 17), and epidermoid cyst (one of 17). The authors subclassified the ovarian mucinous carcinoids into three groups based on microscopic features: well-differentiated, atypical, and carcinoma arising in mucinous carcinoid (to avoid confusion with a collision tumor, such as a mucinous cystadenocarcinoma extrinsic to the ovarian mucinous carcinoid). The only stage II and III tumors were two carcinomas arising in mucinous carcinoids, and these were found in the only patients to die from the disease. The authors also presented features that help distinguish these tumors from mucinous carcinoids metastatic to the ovary, Krukenberg tumors (which were evaluated for the expression of neuroendocrine markers in this study and were positive in seven of 10 cases), primary ovarian carcinoids, including strumal carcinoids, mucinous cystic tumors with neuroendocrine cells, and neuroendocrine carcinomas of the small or nonsmall-cell type.

Baker PM, Olivia E, Young RH, et al. Ovarian mucinous carcinoids including some with a carcinomatous component. Am J Surg Pathol. 2001;25:557-568.

Reprints: Dr. Esther Olivia, Dept. of Pathology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114