[427] Touch Preparations of Core Biopsies. Impact on Target Therapy Selection Eligibility

Leung Chu Tong, Dorota Rudomina, Maria Friedlander, Oscar Lin. Memorial Sloan-Kettering Cancer Center, New York, NY

Background: Core biopsies (CB) have played an increased role in the management of different cancers and, sometimes even replaced fine needle aspiration specimens. These CB are often used to perform ancillary studies such as immunohistochemical and molecular studies. These ancillary studies are critical for selection of targeted therapy in certain organs and cancers. Although most of these studies can be performed on cytologic material, CB are often used instead due to protocol requirements. Many institutions have used touch preparations (TP) to evaluate the adequacy of CB at the time of procedure instead of the traditional frozen section. The evaluation of TP can provide rapid on site evaluation that a target lesion has been sampled, but the impact of TP on the adequacy of CB for diagnosis and ancillary studies for target therapy selection has not been addressed in a large series.
Design: CB specimens performed by interventional radiologists during a period of 6 months were included in this study. The CB were obtained from many different sites, including but not restricted to lung, kidney, lymph nodes, liver and soft tissue. A TP slide of the resulting core was prepared by the radiologist and subsequently air dried and stained with a modified Giemsa stain. The TP specimen was evaluated on site by a cytotechnologist to assess specimen adequacy. TP specimens were later evaluated by a cytopathologist, while CB were evaluated by a surgical pathologist. The diagnoses of the TPs and concurrent CB were compared to identify discrepancies.
Results: A total of 1221 CB were included in this series. A discrepancy between the CB and the TP was identified in 53 cases (4.3%) of cases. The reason for the discrepancy in 20 cases (1.6%) was the presence of neoplastic cells in the TP slides only, with no diagnostic material identified in the CB. The discrepancy in the remaining 33(2.7%) cases was due to the presence of diagnostic neoplastic cells in the CB only with the TPs containing either only benign elements or too few cells to be considered diagnostic.
Conclusions: TP represents a convenient method to assess whether a target lesion has been sampled; however, the use of TPs might lead to depletion of neoplastic cells in the CB as most neoplastic cells may be removed and retained on the TP slide. The loss of neoplastic cells in the CB has the potential to hinder the evaluation of markers used for target therapy selection. Furthermore, TPs with low cellular yield may lead to false negative results in corresponding CB.
Category: Cytopathology

Monday, March 4, 2013 1:00 PM

Poster Session II # 77, Monday Afternoon

 

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