Evaluation of inadequate, indeterminate, false-negative and false-positive cases in cytological examination for breast cancer according to histological type.

BACKGROUND: We previously investigated the current status of breast cytology cancer screening at seven institutes in our area of southern Fukuoka Prefecture, and found some differences in diagnostic accuracy among the institutions. In the present study, we evaluated the cases involved and noted possible reasons for their original cytological classification as inadequate, indeterminate, false-negative and false-positive according to histological type. METHODS: We evaluated the histological findings in 5693 individuals who underwent cytological examination for breast cancer (including inadequate, indeterminate, false-negative and false-positive cases), to determine the most common histological types and/or features in these settings and the usefulness/limitations of cytological examination for the diagnosis of breast cancer. RESULTS: Among 1152 cytologically inadequate cases, histology revealed that 75/173 (43.6%) cases were benign, including mastopathy (fibrocystic disease) in 38.6%, fibroadenoma in 24.0% and papilloma in 5.3%. Ninety-five of 173 (54.9%) cases were histologically malignant, with scirrhous growing type, invasive ductal carcinoma (SIDC) being significantly more frequent (49.5%) than papillotubular growing type (Papi-tub) (P < 0.0001), solid-tubular growing type (P = 0.0001) and ductal carcinoma in situ (DCIS) (P = 0.0001). Among 458 indeterminate cases, 54/139 (38.8%) were histologically benign (mastopathy, 30.0%; fibroadenoma, 27.8%; papilloma, 26.0%) and 73/139 (52.5%) were malignant, with SIDC being the most frequent malignant tumor (37.0%). Among 52 false-negative cases, SIDC was significantly more frequent (42.3%) than DCIS (P = 0.0049) and Papi-tub (P = 0.001). There were three false-positive cases, with one each of fibroadenoma, epidermal cyst and papilloma. CONCLUSIONS: The inadequate, indeterminate, false-negative and false-positive cases showed similar histological types, notably SIDC for malignant tumors, and mastopathy, fibroadenoma and papilloma for benign cases. We need to pay particular attention to the collection and assessment of aspirates for these histological types of breast disease. In particular, several inadequate, indeterminate and false-negative cases with samples collected by aspiration were diagnosed as SIDC. These findings should encourage the use of needle biopsy rather than aspiration when this histological type is identified on imaging. Namely, good communication between clinicians and pathological staff, and triple assessment (i.e., clinical, pathological and radiological assessment), are important for accurate diagnosis of aspiration samples. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7349809170055423.

Comparison of the accuracy of breast cytological diagnosis at seven institutions in southern Fukuoka Prefecture, Japan.

OBJECTIVE: Cytological examination is inexpensive and relatively simple to carry out and deserves utilization in breast cancer screening. We investigated the status of cytological diagnosis at seven facilities in southern Fukuoka Prefecture, Japan. METHODS: We collected data on the criteria for cytological judgments and status of breast cytological diagnosis at seven different facilities in this region. RESULTS: Among 5693 individuals who underwent breast cytological examination, analyses were conducted on 1250 individuals (22.0%) in whom cytological diagnoses were confirmed by histological diagnoses. Among these patients, cytological diagnosis had an absolute sensitivity of 71.9%, a specificity of 76.0%, a false-negative value of 6.7% and a false-positive value of 0.08%. At three facilities with relatively large numbers of cases (>300), excluding a facility for specialized breast disease, similar trends of high complete sensitivity (94.3, 95.6 and 97.1%, respectively) and low absolute sensitivity (60.4, 74.8 and 57.2%, respectively) were found. No false-negative or false-positive cases were seen in individual facilities with relatively low numbers of cases (<150). CONCLUSIONS: The accuracy of cytological diagnosis at the facilities we surveyed was relatively high compared with the goals of assessment of diagnostic accuracy. However, the performance was dependent on the facility type, i.e. number of cases, staff involved and whether it was specialized or not, making the diagnosis specific for this region. We recommend that management of the accuracy of cytological diagnosis be undertaken jointly by multiple facilities to establish systems in Japan that lead to more useful diagnostic tools.