Imprint cytology of vacuum-assisted breast biopsy specimens: a rapid diagnostic tool in non-palpable solid lesions

Objective:  Imprint cytology provides a rapid preliminary diagnosis shortly after the completion of breast biopsy. This study aims to assess the validity of imprint cytology for the pre-operative diagnosis of non-palpable mammographic solid lesions excised by vacuum-assisted breast biopsy (VABB).
Methods:  Seventy-two women with non-palpable Breast Imaging Reporting and Data System 3 and 4 mammographic solid lesions without microcalcifications underwent VABB on the stereotactic Fischer's table with 11-G Mammotome vacuum probes. Imprint samples were examined (Diff-Quick stain, modified Papanicolaou stain and May-Grünwald–Giemsa). The cores were dipped into a CytoRich Red Collection fluid for a few seconds in order to obtain samples with the use of the specimen wash. After the completion of cytological procedures, the core was prepared for routine pathological study. The pathologist was blind to the preliminary cytological results. The cytological and pathological diagnoses were comparatively evaluated.
Results:  The sensitivity of the cytological imprints for cancer was 90%. The specificity of the method for cancer diagnosis was 100%. Two precursor lesions were present in the material: one case of atypical ductal hyperplasia, which was successfully detected, and one case of lobular neoplasia, which escaped detection. The cytological imprints were inadequate in four out of 72 cases (5.6%), but none of them were included within the malignant subgroup.
Conclusions:  Imprint cytology seems to be an important adjunctive tool in the management of patients with non-palpable mammographic solid lesions. Its very satisfactory sensitivity and optimal specificity could establish its use in general clinical practice.