A case report of micropapillary variant of pure mucinous carcinoma

Abstract

Background : A subtype of pure mucinous carcinoma reported by Ng shows a micropapillary pattern and lymphtrophic proliferation. This subtype may show high lymphometastasis similar to invasive micropapillary carcinoma of the breast.
Case : A 1.35×1.1×0.7 cm hypoechoic lesion was found in the C area of the left breast of a 37-year-old woman in the US in an annual health checkup. Fine-needle aspiration biopsy showed many micropapillary clusters against a mucinous background. Cells in individual clusters showed nuculear atypia and occasional mitotic figures. Histology showed mucinous carcioma with micropapillary proliferation and multiple lymphatic permeation.
Conculusion : Care is required in the cytological diagnosis of mucinous carcinoma to differentiate its micropapillary variant from pure mucinous carcinoma.