Critical values in cytology

The concept of critical values (CVs) is well established in clinical pathology, and has only recently been suggested in surgical pathology. To evaluate CVs in cytology, we reviewed 2,000 cytology reports at two large academic medical centers. Cases considered CV included unexpected malignancy, disagreement between immediate interpretation and final diagnosis in fine-needle aspirations (FNAs), and evidence of microorganisms in non-gynecology (non-GYN) and FNA specimens. We identified 52 CV cases (2.6%), including 0.25% (1/400) GYN, 1.88% (15/800) non-GYN, and 4.5% (36/800) FNA. Most of these (42 cases) were unexpected malignancies. Documentation of physician notification was present in 30 out of 52 cases. We also did a survey with 22 cytopathologists and 13 clinicians at large academic medical centers. The participants were asked to rate 18 different possible CVs from 1 to 3 as follows: (1) no phone call necessary, (2) phone call within 24 hr, (3) phone call as soon as possible (ASAP). Participants could also list additional diagnoses they believed constituted a CV. Most respondents agreed on the need for a phone call ASAP in many situations, and important additional CV cases were suggested. We suggest that a consensus conference of leaders in anatomic pathology and clinicians might prove useful to propose guidelines for CVs in cytology.