Effective Application of the Cellient™ Automated Cell Block Processor with Immunocytochemistry and Molecular Biology in Oncopathology
Albert J Suurmeijer. UMCG, Groningen, Netherlands
Background: Immunocytochemistry and molecular biologic techniques performed on cell block material provide useful additional clinical information in cytopathology and oncopathology. A major factor determining the efficacy of a cell block technique is fixation of cell material. Most often formalin is used for cell fixation and only few data are available on the use of methanol-based solutions, e.g. those routinely used with the ThinPrep technique.
Design: We tested the accuracy of immunocytochemistry (ICC) and molecular diagnostic methods (ISH and PCR), using cell blocks made with the automated Cellient processor after methanol-based (PreservCyt) fixation of body cavity fluids and FNA material, applying 29 different antibodies. The quality of DNA and RNA after methanol fixation was tested with in situ hybridization using a SYT gene break-apart assay and EBER probes, as well as PCR using primer sets resulting in products of 100, 200, 300, 400, 500, and 600 bp. Moreover, we estimated the additional oncodiagnostic value of immunocytochemistry on Cellient cell blocks in a cohort of 100 consecutive cytology cases. For each case, the following items were scored: 1. adequacy of the specimen in terms of cellularity; 2. presence of benign or malignant tumor cells; 3. possibility to make a definitive diagnosis of a major tumor type (benign tumor, carcinoma, melanoma, lymphoma, others); 4. possibility to subtype carcinoma (adenocarcinoma, squamous cell carcinoma, neuroendocrine carcinoma); 5. in case of metastatic adenocarcinoma and small cell neuroendocrine carcinoma: possibility to determine the primary tumor location (lung, breast, thyroid, prostate); 6. determination of biomarkers relevant to tumor therapy (CD117 for GIST, ER and Her2/neu for breast carcinoma).
Results: Of 29 antibodies, 23 showed consisted ICC results on at least three consecutive samples. Distinctive and strong hybridization signals were observed for SYT and EBER. PCR products of linearly ascending bp size were readily observed with gel electrophoresis.
In our cohort of 100 consecutive cytology cases, additional and relevant diagnostic information was provided by ICC in 28 cases, applying diagnostic algorithms for sensitive ICC with this cell block technique.
Conclusions: Methanol fixation with the Cellient cell block technique allows for sensitive and specific immunocytochemistry and molecular biologic analysis. The latter will become increasingly important for the determination of patient tailored treatment in selected cancer types in the near future.
Tuesday, March 20, 2012 9:00 AM
Platform Session: Section F, Tuesday Morning