Abstract
Background : A solid papillary carcinoma (SPC) is a papillary carcinoma characterized by a delicate fibrous vascular core. The tumor cells consist of mildly atypical, acidophilic, ovoid- and spindle-shaped cells. SPCs frequently exhibit mucus retention and neuroendocrine differentiation. Fine-needle aspiration cytology (FNAC) has revealed cell clusters with loose cellular adhesiveness in large quantities. Tumor cells consist of small ovoid-shaped cells, which show nuclear laterality, and spindle-shaped cells. These nuclear atypia are mild.
Case : A 70-year-old woman was noted to have an abnormal shadow on mammography. She underwent FNAC of the tumor in the EC area of the right breast. We observed cell clusters consisting of spindle-shaped cells with mild atypia. Based on a needle biopsy of the tumor, a malignancy was suspected, thus a partial resection of the right breast and a sentinel lymph node biopsy were performed. Histologically, the tumor was a solid mass consisting of spindle-shaped cells. The neuroendocrine differentiation was confirmed by immunohistochemistry. She was diagnosed as having an SPC with invasion.
Conclusion : Based on FNAC, an SPC may consist only of mildly atypical, spindle-shaped cells in clusters or in isolation.
