Immunophenotyping of cytologic specimens by flow cytometry

Area of Science:

• Hematology
• Cytopathology
• Immunology

Background:

• Immunophenotyping by flow cytometry is crucial for diagnosing hematopoietic neoplasms.
• Cytologic specimens are often overlooked for flow cytometry due to perceived low cellularity, despite being ideal cell suspensions.

Purpose of the Study:

• To evaluate the utility of immunophenotyping cytologic specimens using flow cytometry.
• To assess diagnostic yield across different specimen types: cerebrospinal fluid, body cavity fluids, and fine needle aspirates.

Main Methods:

• Retrospective review of cytologic specimens analyzed by flow cytometry between 1988 and 1991.
• Analysis included cerebrospinal fluid (31 cases), body cavity fluids (32 cases), and fine needle aspirates (118 cases).
• Number of cell surface markers used ranged from 1 to 22 depending on the specimen type.

Main Results:

• Cerebrospinal fluid analysis had inadequate cells in 15/31 cases, with only 5 showing monoclonal proliferation.
• Body cavity fluids (peritoneal, pleural, pericardial, bronchoalveolar lavage) were analyzable in all cases, but only 7/32 showed monoclonal proliferation.
• Fine needle aspirates (FNA) yielded adequate cells in 116/118 cases, with 61 demonstrating monoclonal proliferation.

Conclusions:

• Flow cytometry immunophenotyping is of limited value for cerebrospinal fluid analysis, requiring prior study knowledge.
• Analysis of body cavity fluids is technically feasible but less frequently diagnostic for monoclonal proliferation.
• Flow cytometry immunophenotyping is a valuable adjunctive technique for fine needle aspirates, providing adequate cellular material for analysis.