Fine needle aspiration cytology of solid papillary carcinoma of the breast. A report of four cases

BACKGROUND: Solid papillary carcinoma of the breast (SPCB) is a distinctive form of papillary carcinoma that tends to occur in older women and usually has a favorable prognosis. CASES: We report the cytologic and histologic findings in four cases of SPCB. All but one of the patients were elderly women (mean age, 66 years). Three patients presented with breast masses, and one patient presented with a breast mass and nipple discharge. Cytology demonstrated moderately to highly cellular smears with irregular groups of predominantly monolayered epithelium composed of small, polygonal or cuboidal cells with eosinophilic cytoplasm and rounded, eccentrically placed nuclei. Papillalike clusters with thin, fibrovascular cores were also observed. Immunocytochemical expression of synaptophysin was present in two cases. The diagnosis of SPBC was subsequently confirmed histologically and immunohistochemically. CONCLUSION: The FNA of SPCB displays some features that may be helpful in its correct identification preoperatively.