The issue observed in the image is most likely caused by which of the following?

• A. Cross contamination during deparaffinization
• B. Tissue carryover in staining
• C. Incomplete dehydration
• D. Overfixation

Answer: (A)

Contamination transferring between tissue sections during processing can create artifacts that do not reflect the actual tissue. Specifically, during deparaffinization slides are exposed to solvents that remove paraffin and prepare sections for staining. If the processing setup allows residues, paraffin fragments, or even remnants from a previously run slide to stick to racks, forceps, or the bath, these materials can migrate onto the current slide. That cross‑contamination often shows up as ghost outlines, stray staining, or lines that mimic parts of another tissue, indicating the problem happened during the wax removal step rather than during staining or dehydration.

This is why the observed issue is best explained by cross contamination during deparaffinization. Poor dehydration would cause residual water issues and weak staining, overfixation would dull antigen staining, and tissue carryover in staining points to problems during the staining step itself rather than during paraffin removal, making those explanations less consistent with the artifact seen.