title: Fine needle aspiration cytology of ductal breast carcinoma with neuroendocrine differentiation. Review of eight cases with histologic correlation.
abstract: OBJECTIVE
  To describe the fine needle aspiration cytology findings of ductal breast carcinoma with neuroendocrine differentiation and correlate them with the histologic appearance.
  
  
  METHODS
  We reviewed the cytologic features of eight cases of ductal carcinoma with neuroendocrine differentiation in the files of Pamela Youde Nethersole Eastern Hospital during the three-year period 1998-2000. Immunohistochemical study for neuroendocrine markers was performed, with ultrastructural correlation.
  
  
  RESULTS
  All cases showed similar cytologic features. The smears were of moderate to high cellularity with predominantly dispersed or loosely cohesive tumor cells. The carcinoma cells were mostly of low cytologic grade. They possessed round and relatively uniform, eccentric nuclei; finely stippled chromatin; sometimes small, distinct nucleoli; and discrete cell borders. Abundant eosinophilic and focally granular cytoplasm was a common finding. In some of the cases there was accentuation of staining in the paranuclear region; it correlated with aggregates of dense core neurosecretory granules seen ultrastructurally. Mucoid substance was seen in the background in some of the aspirates. Histologic examination of the tumors showed invasive ductal carcinoma with an organoid growth pattern and sometimes mucinous component. The neuroendocrine differentiation was confirmed immunohistochemically.
  
  
  CONCLUSIONS
  Although this subtype of ductal carcinoma probably carries no significant prognostic value per se, it has distinct cytologic features, rendering preoperative diagnosis possible. Recognition of this entity is important in order to avoid the misdiagnosis of neuroendocrine tumor metastatic to the breast.
authors.affiliation: Departments of Pathology and Surgery, Pamela Youde Nethersole Eastern Hospital, 3 Lok Man Road, Chai Wan, Hong Kong. ngwk@yahoo.com
authors.forename: Wai-Kuen
authors.initials: WK
authors.lastname: Ng
authors.forename: Cycles S P
authors.initials: CS
authors.lastname: Poon
authors.forename: James H B
authors.initials: JH
authors.lastname: Kong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000473:pathology*; D018278:Carcinoma, Neuroendocrine / Q000473:pathology; D002454:Cell Differentiation; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008875:Middle Aged