BENIGN

  – Consistent with fibroadenoma (see comment)

COMMENT: The ThinPrep slide and aspirate smears are moderately cellular, showing branching clusters of ductal cells, as well as a rare fragment of metachromatic stroma and a background of stripped nuclei. These features are most consistent with a fibroadenoma. Clinical and radiologic correlation is suggested.

 

  – Fibroadipose tissue (see comment)

COMMENT: The ThinPrep slide is hypocellular showing fragments of mature adipose tissue with no epithelial cells identified. While these findings provide no support for malignancy, clinical and radiologic correlation is recommended to ensure that the specimen is representative of the targeted lesion.

 

  – Fat necrosis (see comment)

COMMENT: The aspirate smears show foamy macrophages, multinucleated giant cells, and blood admixed with a dirty background. No atypical or malignant cells are seen. These findings are consistent with fat necrosis. Clinical and radiologic correlation is suggested.

 

  – Fibrocystic change (see comment)

COMMENT: The ThinPrep slide shows clusters of cytologically bland duct epithelium associated with myoepithelial cells and apocrine metaplastic cells. The background contains foamy macrophages and scattered fragments of fibrofatty stroma. These features are consistent with fibrocystic change. Clinical and radiologic correlation is suggested.

 

  – Paucicellular cyst fluid (see comment)

DIAGNOSTIC COMMENTS: The ThinPrep slide shows numerous histiocytes and a background of proteinaceous fluid. There is no evidence of epithelial malignancy. Clinical and radiologic correlation is suggested.

 

  – Gynecomastia (see comment)

DIAGNOSTIC COMMENTS: The aspirate smears are moderately cellular and show numerous sheets of cohesive, moderately crowded ductal cells with intercalated myoepithelial cells, as well as stromal and fatty fragments. The nuclei are bland with minimal enlargement and smooth nuclear contours. Naked bipolar nuclei are present in the background. There is no evidence of epithelial malignancy. These features are most consistent with gynecomastia. Clinical and radiologic correlation is recommended.

 

ATYPICAL

  – Atypical (see comment)

COMMENT: The ThinPrep slide and aspirate smears are moderately cellular and show sheets and clusters of ductal cells in a background of foamy histiocytes. The ductal cells exhibit mild nuclear enlargement with focal nuclear membrane irregularities and a paucity of myoepithelial cells. Overall, the features are atypical and may represent a benign hyperplastic process, but the possibility of a well-differentiated carcinoma cannot be completely excluded. Clinical and radiologic correlation is suggested, as well as consideration for tissue biopsy for definitive diagnosis.

 

  – Papillary lesion (see comment)

COMMENT: The aspirate smears are moderately cellular and contain clusters of cells, as well as many single cells, with a columnar appearance. Proteinaceous material and scattered histiocytes are noted in the background. These features are consistent with a papillary lesion. Since a distinction cannot be made between benign and malignant papillary neoplasm based on cytologic features, excision of the lesion is suggested for further histologic evaluation.

 

MALIGNANT

  – Adenocarcinoma (see comment)

COMMENT: The aspirate smears are abundantly cellular and show groups of malignant epithelial cells with increased nuclear to cytoplasmic ratios, marked nuclear pleomorphism, prominent nucleoli, and irregular nuclear borders. There is a paucity of myoepithelial cells and single intact cells are identified. In addition, the background is notable for necrosis. These findings are diagnostic of adenocarcinoma.

 

Last updated: September 2, 2019