Evaluation of nipple discharge cytology and diagnostic value of red blood cells in cases with negative cytology: a cytohistologic correlation.

OBJECTIVE: To evaluate the sensitivity and specificity of nipple discharge cytology and to determine the diagnostic value of the presence of red blood cells (RBCs) in cases with negative cytology. STUDY DESIGN: Samples were received either as air-dried or alcohol-fixed slides. All cytology cases were reported by cytopathologists in the Hammersmith Pathology Department. RESULTS: We identified 98 consecutive female patients with nipple discharge cytology in the Hammersmith and Charing Cross hospitals during the period of May 2007 to May 2009. The cytodiagnoses were as follows: 86 cases had negative cytology, 9 cases were C3 (atypia but likely benign), and 3 cases were suspicious for or consistent with malignancy. Thirty of these cases had subsequent biopsy and showed: 9 benign cases, 3 cases with atypical papilloma and 3 cases with a malignant diagnosis (in situ and/or invasive ductal carcinoma). All suspicious and malignant cases with available macroscopic description (whether positive or negative on nipple discharge cytology) were blood stained and on microscopy contained RBCs. CONCLUSION: Nipple discharge cytology is a useful method in the diagnosis of malignant and suspicious cases. Further evaluation is needed to assess the value of the presence of RBCs in cases with negative cytology and its correlation with a subsequent diagnosis of malignancy.