Immunohistochemical analysis of gel-transferred cells in cytologic preparations following smear division

Transferred-tissue Microarray for Fluorescence In Situ Hybridization Test for Human Epidermal Growth Factor Receptor 2 in Breast Cancer

CONTEXT

Human epidermal growth factor receptor 2 (HER2) status of breast carcinomas is usually determined by immunohistochemical (IHC) staining and, if the IHC results are equivocal, in situ hybridization (ISH). Multiple ISH tests are sometimes required for multiple primary or metastatic tumors. A method for multiplex ISH test on tissues from multiple blocks is helpful in these situations.

OBJECT

To evaluate the clinical application of transferred-tissue microarray (TTM) followed by a dual-probe HER2 fluorescence in situ hybridization (FISH).

DESIGN

A 3×3 TTM technique was successfully established using 152 invasive mammary carcinoma tissue fragments. To evaluate detection of HER2 positive tumors, this cohort was enriched with tumors with IHC scores of 2 and 3.

RESULTS

The HER2 FISH analyses revealed that all transferred-tissue fragments were adequate for determining HER2 amplification. Tissue loss was minimal and had no major adverse effects on interpretation of the test results. Of the 81 tumors with IHC scores of 3, 72 (88.8%) were positive for HER2 FISH. The remaining tumors were negative for HER2 FISH in both TTM and reflex whole tissue section. Finally, FISH results for tumors with IHC scores of 2 were compared between TTM and whole tissue section. Concordance was high in overall positivity/negativity (100%), HER2 copy number (97.5%), and HER2/CEP17 ratio (100%).

CONCLUSIONS

This novel technique is a reliable option for performing multiple HER2 FISH tests simultaneously in clinical and research-oriented settings with less tissue damage compared with conventional tissue microarray techniques.

Characterizing specimen quality of cell block samples in an era of personalized diagnostics: analysis of 221 lymph node fine-needle aspirations

INTRODUCTION

Cell block (CB) preparations of fine-needle aspirates (FNAs) are utilized for patient management, which requires retention of representative material on slides. Personalized medicine demands quality CB specimens. There is no standard protocol for CB preparation, often resulting in suboptimal slides. The utility of using two CB slides in lymph node (LN) FNA cases was investigated.

MATERIALS AND METHODS

We cut 10 serial sections from each CB, slides 1 and 5 are stained and considered the first and second cuts, respectively; the remaining slides are reserved for ancillary studies. Hematoxylin and eosin-stained CBs of 221 consecutive LN FNA cases were reviewed; qualitative and quantitative assessment of diagnostic value was made on sections 1 and 5.

RESULTS

Of the 221 cases, 46.1% (102) had comparable diagnostic cellularity (equally representative) on both slides, whereas 26.7% (59) and 27.1% (60) had more representative material on the first and second cuts, respectively (P = 0.52). Differences between the representativeness of first and second CB cuts of intrathoracic lymph nodes were minor (n = 192, P = 0.065). Differences between the first and the second slide representativeness of superficial (n = 22, P = 0.98) and intra-abdominal lymph nodes (n = 7, P = 0.38) are limited because of small sample sizes.

CONCLUSION

One CB cut can be suboptimal for diagnosis. In our study, inclusion of a second slide increases equal representativeness from 46.1% to 73.2%. These limited observations recognize the need for additional investigations regarding the collection and preparation of CBs.

Construction of tissue microarrays using pre-existing slides as source of tissue when paraffin blocks are unavailable

Aim

To develop and validate a technique for construction of intermediate density tissue microarray (TMA) slides based on the transfer of tissue from pre-existing routine slides provided for pathology diagnosis with validation to show preservation of morphology and antigenicity of the transferred tissue.

Methods

Prostate cancer patch TMAs were constructed using 20 cores acquired from radical prostatectomy histology slides. The preservation of morphology and antigenicity of these patch TMAs were tested with immunohistochemistry (IHC) in comparison to a traditional TMA.

Results

After IHC staining, 35 of 39 cores (89.7%) on the patch TMA were intact compared with 39 of 40 cores (97.5%) on the traditional TMA. Expression patterns and density of the antigens (34BE12, p63 and AMACR) on the patch TMA were almost identical to the traditional TMA.

Conclusions

Patch TMA represents a viable alternative for tissue-based IHC studies when paraffin blocks are unavailable. This may be a valuable tool for allowing use of archival slide material for IHC and enable a standardized TMA platform to be used when the slides sent for review from other institutions are the only source of tissue available.

Duodenal carcinoid tumor: report of a case diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy with immunocytochemical correlation

Fine-needle aspiration biopsy is a reliable and accurate method for the endoscopic diagnosis of gastrointestinal malignancies and it is particularly well suited for evaluation of submucosal lesions. We report the cytopathologic findings of a case of malignant carcinoid tumor of a 44-year-old male who presented with melena and a nonhealing duodenal ulcer. Endoscopic ultrasound examination revealed a submucosal lesion in the pyloric region. Fine-needle aspiration revealed abundant cellularity with tumor cells arranged in sheets and loose groups and dispersed single cells in a clean background. Papillary fragments, capillaries cuffed by tumor cells, and rosette formation were also noted. The cells were moderate in size, round to oval, with a small subpopulation of spindle-shaped cells. The nuclei were uniform, round to oval, with smooth nuclear borders. The chromatin pattern was finely granular with a salt-and-pepper appearance. The cytoplasm of the cells was small to moderate in amount, pale, and showed fine granularity. The differential diagnosis included a neuroendocrine neoplasm vs. an epithelioid gastrointestinal stromal tumor. The tumor cells were focally positive for chromogranin and negative for CD34, supporting the diagnosis of a neuroendocrine neoplasm. The differential diagnosis of primary gastrointestinal carcinoid tumors from gastrointestinal stromal tumors can be very difficult in cytologic material. In cases when diagnostic material is scant, or only present on one smear, the use of smear division and cell transfer in order to perform immunocytochemical stains may be of considerable value to confirm the neuroendocrine nature of the neoplasms.