Medullary breast carcinoma: a case report with cytological features and histological confirmation

Medullary breast carcinoma in an 18-year-old female: report on one case diagnosed on fine-needle cytology sample

Medullary breast carcinoma (MBC) is a rare epithelial malignancy of the breast accounting for about 1-7% of all breast carcinomas. It is characterized by well-defined borders, a syncytial/solid pattern of growth of high grade atypical cells showing no glandular differentiation and a massive diffuse lympho-plasmacytic peritumoral infiltrate. Despite the high-grade atypias characterizing this neoplasm, MBC has been reported to have a better prognosis when compared with the common infiltrating duct carcinoma. MBCs typically lack estrogen and progesterone receptor (ER and PgR) expression and have a low incidence of ERBB2 overexpression. Genetically, they are often associated with BRCA-1 oncogene mutations and TP53 alterations. While MBC generally occurs in middle-aged women, ranging from 45 to 52 years of age, we report the case of a 18-year-old female patient which was diagnosed by means of fine-needle cytology sample.

Fine-needle aspiration cytology of medullary breast carcinoma: report of two cases and review of the literature with emphasis on differential diagnosis

Medullary carcinoma is a rare variant of breast carcinoma with a relatively good clinical prognosis as strictly defined. Characteristic features on fine-needle aspiration cytology (FNAC) allow medullary carcinoma to be considered in the cytologic differential diagnosis. We present two FNAC cases with such features, including high cellularity with clusters and single intact malignant cells, bizarre stripped nuclei with prominent nucleoli in a lymphoplasmacytic background, and illustrate one case in liquid-based preparation. Surgical excision revealed that one patient had medullary carcinoma, while the second patient had high-grade infiltrating ductal carcinoma. Breast FNAC samples with syncytial fragments, bizarre nuclei with prominent nucleoli, and a chronic inflammatory infiltrate should raise the possibility of medullary carcinoma. However, the differential diagnosis also includes high-grade ductal carcinoma, lymphoma, or metastasis to breast or intramammary lymph nodes; thus, histopathologic analysis is required for definitive diagnosis.