The problem shown in the image is most likely due to which factor?

• A. Embedding
• B. Improper embedding
• C. Forceps metastasis
• D. Better cleaning of forceps between specimens

Answer: (C)

Cross-contamination from instrument carryover is the key idea. When forceps or other tools touch more than one tissue block without proper cleaning, tissue from a previous case can be transferred to the next specimen. That transferred tissue then appears on slides from a different patient and can mimic metastatic disease or other pathology, which is exactly what the image would show as an artifact. This phenomenon is known as forceps metastasis and is preventable by using clean, dedicated instruments for each case (or thoroughly cleaning between specimens) and by strict handling protocols.

Embedding or improper embedding would create artifacts related to one specimen’s processing, not tissue from a separate case. And improving cleaning between specimens would prevent forceps metastasis, not cause it.