Immunophenotyping of cytologic specimens by flow cytometry

Abstract

Immunophenotyping by flow cytometry is well established as an ancillary technique in the diagnosis of hematopoietic neoplasms. However, flow cytometry is rarely performed on cytologic specimens because most cytologist are more comfortable with direct microscopy and believe that there is inadequate cellularity for analysis. Paradoxically, cytologic material is usually cell suspensions making it ideal for flow cytometry. In order to evaluate the usefulness of immunophenotyping cytologic specimens by flow cytometry, we retrospectively reviewed all cytologic specimens submitted to our flow cytometry unit from 1988 to 1991. Thirty-one cerebrospinal fluid specimens were analyzed. There were inadequate cells for analysis in 15 cases. Five showed a monoclonal proliferation; 11 were nondiagnostic. A range (r) of one to six cell surface markers were performed. Thirty-two body cavity fluids were analyzed: 7 peritoneal, 19 pleural, 2 pericardial, and 4 bronchoalveolar lavage. There were cells to analyze in all cases. Seven had a monoclonal proliferation; 25 were nondiagnostic (r = 4-21 markers performed). One hundred eighteen fine needle aspirates (FNA) were reviewed; 58 FNA were radiologically guided, 60 were superficial lesions. There were inadequate cells for analysis in two cases. Sixty-one demonstrated a monoclonal proliferation; 55 were nondiagnostic (r = 1-22 markers performed). We conclude that immunophenotyping by flow cytometry is of limited value for cerebrospinal fluid analysis and that knowledge of previous immunophenotyping studies is essential for correct analysis; analysis of body cavity fluids is easily performed but less often demonstrates a monoclonal proliferation. Immunophenotyping by flow cytometry is a valuable adjunctive technique for FNA and yields adequate cells for analysis.

Pathology of Liver Metastases

“…The accuracy of subclassifying lymphomas using cytomorphological and flow cytometric immunophenotyping has been demonstrated. [35][36][37] Sarcomas Sarcomas are usually characterized by a spindle cell appearance. Gastrointestinal stromal tumors and leiomyosarcomas are the most frequent sarcomas to metastasize to the liver.…”

Diagnostic principles in pleural disease

“…These include: flow cytometry with deoxyribonucleic acid (DNA) analysis [26][27][28] or immunocytometry [29]; electron microscopic examination [30,31]; and immunohistochemical studies [32][33][34]. The theory behind DNA analysis is that malignant cells will have abnormal numbers of chromosomes and, therefore, an abnormal amount of DNA.…”

“…However, studies have shown that DNA analysis via flow cytometry is less sensitive than cytology [26,27], and also has more false positives than cytology [28]. Flow cytometry using immunocytometry can identify the cell lineage (T-or B-cells) and the clonality of a population of lymphocytes [29]. Therefore, this is a useful test when pleural lymphoma is suspected.…”

Enhanced Detection of Malignant Lymphoma in Cerebrospinal Fluid by Multiparameter Flow Cytometry

“…7 The potential advantages of flow cytometry include the rapidity of analysis compared with immunohistochemistry, the ability to enrich for possible malignant cells via gating techniques in samples with mixed cell populations, and the simultaneous evaluation of multiple surface markers on each cell. In the past, limited sample volume, low cell counts, and the presence of cellular debris or reactive lymphocyte populations could lower the sensitivity of flow cytometry in recovering clonal lymphocyte populations.…”