Suppose that a stool specimen was received in the laboratory for an O & P examination. The clinical laboratory scientist on duty performed direct wet preparations and found suspicious forms. An ethyl acetate concentration procedure was done, the top layer was examined, and no suspicious forms were seen. A slide of the sample was stained with Trichrome and again suspicious forms were noted. Which of the following is the most likely explanation for these discrepant results?

Please select the single best answer