Background :The human epidermal growth factor receptor 2 (HER2) is amplified in 20-25% of breast cancers. HER2 overexpression or amplification is associated with a worse clinical outcome and it can predict the benefit from anthracycline and anti-HER2 therapies. The HER2 status has usually been assessed by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) in clinical samples. A new silver-enhanced in situ hybridization (SISH) technique was recently introduced. Therefore we evaluated the usefulness of SISH for detecting HER2 amplification. Methods : Tissue microarrays (TMAs) were constructed with 144 invasive breast cancer tissue samples. We performed IHC, FISH and SISH for HER2 on the tissue sections from the TMAs and we interpreted the results according to the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines. The concordant rates between the two different tests were calculated. Results : HER2 was overexpressed and amplified in 16.9%, 16.9%, and 18% of the cases by IHC, FISH and SISH, respectively. The concordant rates between IHC and FISH, IHC and SISH, and FISH and SISH were 95.1%, 95.7%, and 97.8%, respectively. Conclusions : SISH can be an alternative test for evaluating HER2 amplification because the 97.8% concordance with FISH satisfies the ASCO/ CAP requirement of > 95% concordance with an alternative validated method.

Soft tissue myoepithelioma is a rare neoplasm composed of myoepithelial cells. Here, we describe the cytologic features of soft tissue myoepithelioma arising on the right forearm in an 18-year-old man. The excised tumor (3.0×1.8×1.5 cm) was well-demarcated, yellow-gray, soft, and myxoid. The cytologic smears showed round to spindle, epithelioid, and plasmacytoid cells in the myxoid background. The nuclei were uniform, round to ovoid, with finely distributed chromatin and eosinophilic or pale cytoplasm. The tumor cells demonstrated immunoreactivity for cytokeratin (AE1/AE3), epithelial membrane antigen, S100 protein, and glial fibrillary acidic protein. Electron microscopy showed intermediate filaments, desmosomes, and basal lamina.

Hydatid cysts (echinococcosis) are caused by an infestation with larval tapeworms of the genus Echinococcus. The disease is extensively distributed worldwide, and it has been rarely reported in Korea. We describe the cytologic features of a case of hepatic hydatid cyst in a 28-year-old male. Computed tomography revealed a cystic mass in the right lobe of the liver. A right hemihepatectomy was performed. The aspirated fluid from the hepatic cystic mass was clear. The smears showed protoscolices, hooklets, and a laminated membrane.

Background : At present, adequate prognostic markers for prostate cancer progression are still lacking, in spite of intensive investigation. Accordingly, our study examined the relationship between expression of candidate biomarkers and metastasis in prostate cancer patients. Correlation of molecular markers with prostate-specific antigen (PSA) level, Gleason sum score and tumor stage were also evaluated. Methods : A total of 105 prostate tumor specimens and specimens from 19 cases of nodular hyperplasia were obtained through Yeungnam University Hospital from 2007 to 2008. Immunohistochemical analyses for p16 INK4a , phosphatase and tensin homolog (PTEN), E-cadherin, Ki-67 and Bcl-2 were performed. Results : Overexpression of Bcl-2 was significantly related to bone (p = 0.006) and nodal metastases (p = 0.017). Other biomarkers were not related to metastatic potential. There were statistically significant relationships between increased PSA level and loss of expression of PTEN (p = 0.019) and E-cadherin (p = 0.001). High Ki-67 index was significantly correlated with nodal metastasis (p = 0.029) as well as with loss of p16 INK4a expression (p = 0.002) and high Gleason score (p = 0.011). Conclusions : High Gleason score, Bcl-2 overexpression and increased Ki-67 labeling have significant predictive value in assessing the potential for prostate cancer metastasis. In addition, a high Ki-67 index is related to high Gleason score and loss of p16 INK4a expression.

Recently we experienced three cases of human epidermal growth factor receptor 2 (HER2)-amplified invasive breast carcinomas associated with co-amplification or gain of chromosome 17 centromere (CEP17) in silver-enhanced in situ hybridization (SISH) analysis. These cases revealed 2+ or 3+ staining for HER2 immunohistochemistry and > 6 HER2 copies per cell on SISH analyses. However, the calculated HER2/CEP17 ratios were low (< 2.2) and did not fit within the HER2positive category. We interpreted those cases as HER2-positive tumors based on the number of HER2 copies per cell. There is a potential for misinterpretation of SISH analysis in cases showing increased CEP17 copy number, based on the criterion used for HER2 positivity (HER2 copies > 6 per cell vs HER2/CEP17 ratio> 2.2). We recommend reporting raw SISH or fluorescence in situ hybridization data, including number of cells counted, average numbers of HER2 and CEP17 signals, and the calculated HER2/CEP17 ratio to prevent underreporting of HER2 amplification.