Role of fine-needle aspirate immunophenotyping by flow cytometry in rapid diagnosis of lymphoproliferative disorders

Extranodal Lymphoproliferative Processes and Flow Cytometry

OBJECTIVE

Fine-needle aspiration (FNA) cytology is a safe and cost-effective technique for the diagnosis of lymphoproliferative processes, especially when correlated with clinical and imaging studies. However, cytology alone may be unable to detect a lymphoid neoplastic process, as architectural features are less obvious than in histologic preparations and, in certain cases, reactive processes may mimic lymphoma. Flow cytometry (FC) has been recognized as an important ancillary technique in the diagnosis of lymphoid neoplasms and it can be used in conjunction with FNA in the evaluation of lymphoproliferative processes.

STUDY DESIGN

We performed a review of the published literature concerning FC applied to the detection of salivary glands and thyroid lymphoproliferative processes, which are frequently related to autoimmune diseases and difficult to diagnose by cytomorphology alone.

RESULTS

FC is able to detect and subtype non-Hodgkin lymphomas and may contribute to the exclusion of a neoplastic process in cytologically unclear cases.

CONCLUSIONS

FC can be successfully applied in the differential diagnosis of lymphoproliferative processes in the head and neck region. The FNA-FC combined approach can reduce time to therapy and may prevent unnecessary surgical biopsies.

Fine needle aspirate flow cytometric phenotyping characterizes immunosuppressive nature of the mesothelioma microenvironment

With the emergence of checkpoint blockade and other immunotherapeutic drugs, and the growing adoption of smaller, more flexible adaptive clinical trial designs, there is an unmet need to develop diagnostics that can rapidly immunophenotype patient tumors. The ability to longitudinally profile the tumor immune infiltrate in response to immunotherapy also presents a window of opportunity to illuminate mechanisms of resistance. We have developed a fine needle aspirate biopsy (FNA) platform to perform immune profiling on thoracic malignancies. Matching peripheral blood, bulk resected tumor, and FNA were analyzed from 13 mesothelioma patients. FNA samples yielded greater numbers of viable cells when compared to core needle biopsies. Cell numbers were adequate to perform flow cytometric analyses on T cell lineage, T cell activation and inhibitory receptor expression, and myeloid immunosuppressive checkpoint markers. FNA samples were representative of the tumor as a whole as assessed by head-to-head comparison to single cell suspensions of dissociated whole tumor. Parallel analysis of matched patient blood enabled us to establish quality assurance criteria to determine the accuracy of FNA procedures to sample tumor tissue. FNA biopsies provide a diagnostic to rapidly phenotype the tumor immune microenvironment that may be of great relevance to clinical trials.

Correlation between flow cytometry and histologic findings: ten year experience in the investigation of lymphoproliferative diseases

Objective: To demonstrate the advantages of correlating flow cytometry immunophenotyping with the pathology/ immunohistochemistry of lymph nodes or nodules in the diagnosis of lymphoproliferative diseases. Methods: A retrospective study was carried out of 157 biopsy or fine-needle aspiration lymph nodes/ nodule specimens taken from 142 patients, from 1999 and 2009. The specimens were simultaneously studied with fow cytometry and pathology at Hospital Israelita Albert Einstein. The specimens were prepared in hematoxylin/eosin, Giemsa, or monoclonal antibody stained slides for detecting specific antibodies for the purposes of pathology/immunohistochemical analysis. The samples were hemolyzed and marked with different monoclonal antibody panels for different antigens in fow cytometry immunophenotyping. Results: The diagnostic results of pathology/immunohistochemical studies and flow cytometry immunophenotyping agreed in 115 patients (81%), corresponding to 127 specimens, as follows according to the pathologic diagnosis: 63 patients with non-Hodgkin's B-cell lymphoma; 26 patients with reactive lymphoid hyperplasia; 5 patients with non-Hodgkin's T-cell lymphoma; 4 patients with atypical lymphoid proliferation; 5 patients with a chronic granulomatous inflammatory process; 5 patients with a non-hematologic diagnosis; 2 patients with granulocytic sarcoma; 2 patients with thymoma; 1 patient with byphenotypic leukemia; 1 patient with kappa plasmocytoma; 1 patient with Hodgkin's lymphoma. Subtypes of lymphomas could be classified by associating the two techniques: 19 patients with follicular lymphoma; 15 patients with diffuse large B-cell lymphoma; 7 patients with small lymphocytic B-cell lymphoma/chronic lymphocytic leukemia; 3 patients with mantle cell lymphoma; 1 patient with Burkitt's lymphoma; 1 patient with MALT type lymphoma; 1 patient with post-transplant lymphoproliferative disease; 2 patients with high grade non-Hodgkin's B-cell lymphoma; 1 patient with low grade non-Hodgkin's B-cell lymphoma not otherwise specified; 1 patient with Hodgkin's lymphoma; and 12 patients with B-cell non-Hodgkin's lymphoma not otherwise specified. Conclusion: Flow cytometry adds to the results of morphologic and immunohistochemical studies, facilitating a rapid and accurate diagnosis of lymphoproliferative diseases.