Role of Tetrasomy for the Diagnosis of Urothelial Carcinoma Using UroVysion Fluorescent In Situ Hybridization.

CONTEXT: -UroVysion fluorescent in situ hybridization (FISH) is routinely used to detect urothelial carcinoma (UC). A positive threshold is defined as chromosome polysomy in 4 or more cells, which also includes tetrasomy, a natural product of cell division. OBJECTIVES: -To evaluate tetrasomy for UC detection and explore the relation to the surgical diagnosis or patient history. DESIGN: -The FISH was performed on 1532 urine samples from patients with cytology results and 4 or more years of follow-up. We created separate polysomy and tetrasomy categories and constructed receiver operating curves to determine appropriate thresholds using biopsy (n = 194) as the gold standard. Standard FISH and a novel assay integrating cytomorphology and FISH (Target-FISH) were compared. Matching tissue biopsies of urine samples with 10 or more tetrasomy cells were analyzed. RESULTS: -No significant threshold was found for tetrasomy cells. Exclusion of tetrasomy from the polysomy category changed the threshold from 8.5 to 4.5 cells, increased specificity (59.2% to 78.9%), but reduced sensitivity (78.9% to 65.9%). In Target-FISH, the same approach yielded a specificity of 93.7% and sensitivity of 65.2%. Similarly, specificity improved significantly for low- and high-grade UC, but sensitivity decreased for low-grade UC. No evidence of UC was observed in 95% (52 of 55) of the patients referred for screening who had 10 or more tetrasomy cells by FISH. Matching biopsies for urines containing 10 or more tetrasomy cells showed few or no tetrasomy cells. CONCLUSIONS: -Tetrasomy is a nonspecific finding frequently encountered in urine FISH and should be excluded from the polysomy classification. Target-FISH is an optimal approach, offering the ability to detect rare tetrasomy tumors.

MYC Analysis by Fluorescent In Situ Hybridization and Immunohistochemistry in Primary Adrenal Angiosarcoma (PAA): a Series of Four Cases.

Primary adrenal angiosarcomas (PAA) are rare with 36 cases reported in the English literature. MYC protein expression and gene amplification have been detected in secondary angiosarcoma (AS), and a subset of primary AS. The aim of this study was to report the clinicopathologic features of PAA and examine these tumors for MYC amplification and protein expression in a small series of four cases (resection, n = 4). Three had available material for ancillary studies and were investigated for MYC gene abnormalities and protein expression using fluorescent in situ hybridization (FISH) and immunohistochemistry (IHC), respectively. Tumors occurred in three females and one male with a mean age of 69 (53-75) years. The sizes ranged from 8.5 to 15 (mean 11.5) cm and were epithelioid in morphology. All tumors had prominent necrosis, and the mitotic count ranged from 4 to 41/10 high-power fields (HPFs) (mean 20/10 HPFs, ×400). Immunohistochemically, the tumor cells were positive for CD31 in 4/4 cases, CD34 in 1/4 cases, and cytokeratin in 4/4 cases. The mean follow-up period was 10.8 (3-19) months, of which three patients died of disease with distant metastases, and one patient was alive with disease. MYC nuclear staining was identified in the three cases tested. Two cases showed polysomy of chromosome 8 without MYC amplification or rearrangement. Two MYC-positive cases by IHC demonstrated copy number gain in chromosome 8, and one MYC-positive case was not associated with a chromosome 8/MYC gene abnormality. In the context of new targeted therapies, MYC positivity in PAA may be clinically valuable in treating patients with these aggressive neoplasms.