Fine needle aspiration cytology of fibroadenoma with multinucleated stromal giant cells. A review of cases in a six-year period.
OBJECTIVE
To describe the fine needle aspiration cytology findings of fibroadenoma with multinucleated stromal giant cells, with histologic correlation.


METHODS
The author reviewed the cytologic findings of two cases of fibroadenoma with multinucleated stromal giant cells from the file of Pamela Youde Nethersole Eastern Hospital in a six-year period from 1995 to the end of 2000. The diagnosis was confirmed by histologic examination of the lumpectomy specimens.


RESULTS
The two cases had similar cytologic findings. The direct smears contained cohesive clusters of bland-looking ductal cells arranged in a "staghorn" pattern. Numerous naked nuclei were also seen in the background. Also, there were occasional multinucleated giant cells in isolation. These giant cells contained 5-10 randomly arranged, round to oval nuclei, fine chromatin and sometimes distinct nucleoli. The cytoplasm was abundant and pale staining, and the cell border was ill defined. Associated epithelioid histiocytes and foamy macrophages were not seen. Histologic examination of the lumpectomy specimens showed architectural features of fibroadenoma with pericanalicular and intracanalicular patterns. In addition, scattered multinucleated giant cells with focal degenerative change were noted in the tumor stroma. Their stromal nature was confirmed by immunohistochemical study.


CONCLUSIONS
Multinucleated stromal giant cells are rarely identified in fine needle aspiration biopsies of fibroadenoma. Recognition of this peculiar finding may help to avoid misdiagnosis of other, more sinister conditions, such as phyllodes tumor and metaplastic carcinoma.
Ng
Wai-Kuen
WK
Department of Pathology, Pamela Youde Nethersole Eastern Hospital, 3 Lok Man Road, Chai Wan, Hong Kong, S.A.R., China. ngwk@yahoo.com
D000328:Adult; D014408:Biomarkers, Tumor / Q000378:metabolism; D001707:Biopsy, Needle; D001943:Breast Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D002277:Carcinoma / Q000473:pathology; D003937:Diagnosis, Differential; D005260:Female; D018226:Fibroadenoma / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D015726:Giant Cells / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000276:immunology / Q000378:metabolism; D015412:Mastectomy, Segmental; D008679:Metaplasia; D003557:Phyllodes Tumor / Q000473:pathology; D012189:Retrospective Studies; D017154:Stromal Cells / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000276:immunology / Q000378:metabolism
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53