Abstract
Background : Solid neuroendocrine carcinoma, a rare neuroendocrine tumor, arises primarily in the breast. We report a case of solid mammary neuroendocrine carcinoma and its cytological and immunocytochemical features.
Case : A 67-year-old woman having a tumor detected in the right breast (CD area) by ultrasound sonography was diagnosed histologically and immunohistochemically from needle biopsy tumor tissue as having solid neuroendocrine carcinoma. Electron microscopy showed neuroendocrine granules in tumor cell cytoplasm. Aspiration biopsy cytology showed numerous tumor cells and characteristic plasma cell-like features with slightly atypical small round eccentric nuclei. Most tumor cells obtained by cell transfer were strongly positive for chromogranin A, synaptophysin, CD56, and neuron-specific enolase, confirming neuroendocrine differentiation.
Conclusion : Immunocytochemical studies using cell transfer for tumor cells were very useful in definitively cytologically diagnosing this solid neuroendocrine carcinoma case.
