[449] Success of EUS-FNAB and Flow Cytometry in the Diagnosis of Deep-Seated Lymphoproliferative Processes

AL Nunez, DN Jhala. University of Alambama at Birmingham, Birmingham, AL

Background: Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) has allowed the sampling of deep tissues, including deep-seated lymph nodes. EUS-FNAB alone is an effective tool in the diagnosis of metastatic epithelial neoplasms in deep-seated lymph nodes. However, the literature regarding the use of EUS-FNAB in the lymphoproliferative process and the yield of flow cytometry specimens via EUS-FNAB is sparse. The aim of this study is to explore the utility of EUS-FNAB in the diagnosis of both deep-seated lymphoma and reactive conditions with an emphasis on the number of passes required to obtain adequate cellularity for flow cytometry confirmation of the diagnosis.
Design: A retrospective search was conducted at our tertiary care center on all EUS-FNAB specimens obtained from January 2006-June 2009. Out of 2140 specimens identified, 706 were aspirates from deep-seated lymph nodes. Ninety-one lymph node aspirates submitted for flow cytometry were reviewed, yielding diagnoses of lymphoma, benign lymph node, reactive lymph node, or metastatic lesion to a lymph node. Flow cytometry data, including the number of passes and of viable cells, were also evaluated.
Results: After two to three passes, the total yield of viable cells per case diagnosed by flow cytometry ranged from 4.0 x 10-3 million to 1.33 x 101 million (mean 3.14 million). Nine of the cases submitted for flow cytometry yielded a quantity of cells insufficient for diagnosis, including three reactive lymph nodes, one metastatic lesion to a lymph node and five benign lymph nodes. Thirty-one specimens from 29 patients (18 males and 11 females aged 39 to 86 years) yielded the diagnosis of lymphoma. There was only one case in which flow cytometry did not confirm malignancy. The diagnosis of lymphoma was supported by surgical biopsy or excision in ten of the cases and by immunohistochemical staining in eight cases. Flow cytometry combined with EUS-FNAB and/or surgical follow up supported the diagnosis of lymphoma in all 31 specimens. In the non-lymphoma cases, 18 specimens showed a reactive process, 8 showed a metastatic lesion, and 34 showed a benign process.
Conclusions: Combined use of EUS-FNAB and flow cytometry can be a powerful tool for the diagnosis of a deep-seated lymphoproliferative process. At least 2 to 3 passes are required for flow cytometry specimens to obtain good viability. Molecular studies on EUS-FNAB specimens will aid in the diagnosis and detection of minimal residual disease.
Category: Cytopathology

Wednesday, March 24, 2010 1:00 PM

Poster Session VI # 65, Wednesday Afternoon

 

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