title: Loss of cell cohesion in breast cytology as a characteristic of neuroendocrine carcinoma.
abstract: OBJECTIVE
  To characterize a specific group of breast cancers displaying a scattered single cell pattern in cytology and correlate it with histologic and immunohistochemical findings.
  
  
  METHODS
  Of 135 consecutive malignant breast cytologic specimens, 12 cases were selected for their scattered single cell pattern on aspiration cytology. Immunohistochemical staining for neuroendocrine markers and prognostic parameters was performed on paraffin sections of corresponding primary breast carcinomas.
  
  
  RESULTS
  In the smears of the 12 cases, highly cellular neoplastic cells with a single cell pattern were observed predominantly. The tumor cells had relatively wide, granular cytoplasm and a low to moderate nuclear/cytoplasmic ratio. Histologically, they were arranged mainly in relatively large, solid nests and occasionally contained a tubular pattern with small amounts of stromal tissue. Five of the 12 cases demonstrated neuroendocrine differentiation with a positive immunoreaction for chromogranin A and synaptophysin. Except for the small mean size of the tumors (P < .01), no significant differences were identified among the prognostic parameters, including a nodal status, estrogen receptor status, growth fraction by Ki-67 or immunoreactivity for c-erbB-2, as compared with the other 123 cases.
  
  
  CONCLUSIONS
  Loss of cell cohesion in breast cytology is a good morphologic marker for identifying neuroendocrine breast carcinoma.
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000276:immunology; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000648:ultrastructure; D015820:Cadherins / Q000032:analysis / Q000276:immunology; D018270:Carcinoma, Ductal, Breast / Q000473:pathology; D018275:Carcinoma, Lobular / Q000473:pathology; D018278:Carcinoma, Neuroendocrine / Q000175:diagnosis / Q000473:pathology* / Q000648:ultrastructure; D002466:Cell Nucleolus / Q000648:ultrastructure; D002467:Cell Nucleus / Q000648:ultrastructure; D002843:Chromatin / Q000648:ultrastructure; D053379:Chromogranin A; D002864:Chromogranins / Q000032:analysis / Q000276:immunology; D003581:Cytodiagnosis; D003593:Cytoplasm / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008198:Lymph Nodes / Q000473:pathology; D008875:Middle Aged; D016708:Synaptophysin / Q000032:analysis / Q000276:immunology
chemical_list: D014408:Biomarkers, Tumor; D015820:Cadherins; D002843:Chromatin; D053379:Chromogranin A; D002864:Chromogranins; D016708:Synaptophysin