Cross-contamination of pathology specimens: a cautionary tale

There are many potential sources of error in clinical practice. An astute clinician must not only work hard to prevent errors but also minimize harmful sequelae that could arise from errors that do occur. A rare but real source of error is cross-contamination of pathology specimens. Such contaminants are colloquially referred to as floaters. If not recognized expediently, floaters can lead to misdiagnoses that may prompt unnecessary and inappropriate treatment. We report the case of a patient with a benign adnexal neoplasm on the face that, due to cross-contamination of pathology specimens, was initially diagnosed as an aggressive invasive melanoma that would have warranted wide local excision and sentinel lymph node biopsy.