A blood sample can be utilized for cytogenetic study of a malignancy if which condition is met?

For a blood sample to be effectively used in cytogenetic studies of a malignancy, the presence of dividing leukemic cells in circulation is essential. This is because cytogenetic analysis often relies on the identification and evaluation of metaphase cells, which are best obtained from cells that are actively dividing. In cases of malignancy, specifically leukemias, the presence of these cells in the bloodstream indicates that the malignancy is active, and allows for the assessment of chromosomal abnormalities that may influence treatment and prognosis.

While factors like patient stability, sample condition, and prior diagnoses are significant in the overall management and treatment of cancer, they do not directly impact the availability of a suitable sample for cytogenetic evaluation. If leukemic cells are not dividing and available for analysis, the cytogenetic study may yield insufficient or no insights into the chromosomal abnormalities required for diagnosis or treatment planning. Thus, the presence of dividing leukemic cells is the key criterion that allows a blood sample to be utilized for cytogenetic studies in malignancy.