What should be confirmed to rule out pseudomosaicism when an abnormal cell is detected in situ?

To rule out pseudomosaicism when an abnormal cell is found in situ, it is essential to confirm the abnormality in other cells within the colony. This is because pseudomosaicism can occur when a single abnormal cell is detected among a background of normal cells due to the presence of an artifact or a technical error, rather than representing a true mosaic situation across the cell population.

By verifying the abnormality in other cells within the same culture or colony, one can establish if the abnormality is a true representation of the cellular population or if it is an isolated finding. This step is crucial for accurate interpretation of the results since true mosaicism would indicate that the abnormality exists in multiple cells, thereby providing a more valid conclusion.

If the abnormality is confirmed in other cells, it supports the diagnosis of a true mosaic condition. Otherwise, if the abnormality is only seen in one or a few cells without confirmation in additional cells from the same culture, there remains a possibility that the finding is due to pseudomosaicism, which should be clarified for precise diagnosis and subsequent clinical management.