Which diagnostic test reveals tartrate-resistant acid phosphatase positive cells?

The diagnostic test that reveals tartrate-resistant acid phosphatase (TRAP) positive cells is flow cytometry. TRAP positive cells are typically associated with certain types of hematologic disorders, notably hairy cell leukemia. This condition is characterized by the presence of abnormal B lymphocytes that exhibit distinctive morphology and specific surface markers.

Flow cytometry is a powerful technique that allows for the analysis of individual cells in a mixed population, making it instrumental in identifying specific cell types based on their surface antigens. In the case of hairy cell leukemia, flow cytometry can identify the increased population of mature B cells that test positive for TRAP, thus confirming the diagnosis.

While a bone marrow biopsy can provide critical information regarding the cellular composition and pathology of the marrow, it may not specifically highlight TRAP positivity on its own without additional staining methods that could be employed. A blood smear primarily evaluates the cells circulating in the blood but lacks the specificity and sensitivity required to identify TRAP positive cells. A CT scan, on the other hand, is utilized for imaging to detect lymphadenopathy or splenomegaly but does not provide any information regarding the cellular characteristics necessary for identifying TRAP positive cells.