1. Artefact (imposter mucin)

Pitfall to the misdiagnosis of mucin on peritoneal fluid cytology

An increasing number of different peritoneal fluid collection devices are now documented to contribute to mucin-like material on the cytology smears. Suction canister liner bags from Receptal (Amsino International, USA), Lifehealthcare Serres and Vacsax have been documented as culprits so far. White flakes from the lining of the bags contribute to the artefact, which stains purple on Papanicolaou stain, with sharp to soft fibrillary edges and multiple central laminations. In contrast, true mucin is pale blue to orange on Papanicolaou stain with hazy ill-defined edges without laminations. This exogenous artefact is a close mimic to extracellular mucin in peritoneal fluid, and the awareness of this artefact is important to avoid misinterpretation.

References

Vazquez, M., & Newman, M. (2019). Imposter mucin: awareness of an important cytology artefact. Pathology, 51(4), 448–449. https://doi.org/10.1016/j.pathol.2018.12.422

van der Griend, R., Lamb, D., Challis, D., Chinnock, M., & Blomfield, P. (2011). A mucinous mimic: identification of a distracting artefact. Cytopathology : official journal of the British Society for Clinical Cytology, 22(2), 133–134. https://doi.org/10.1111/j.1365-2303.2010.00809.x

Quinn, G., Hales, S., Hamid, B., & Meara, N. (2015). Comparison of mucoid-mimic artefact with true mucin in peritoneal cytology samples. Cytopathology : official journal of the British Society for Clinical Cytology, 26(3), 194–196. https://doi.org/10.1111/cyt.12212