Fig. 1Cytologic features of mucinous cystadenocarcinoma. (A) A few scattered, variably sized, irregular clusters of columnar cells with pleomorphism and anisocytosis in a greenish blue mucinous background and necrotic debris. (B) The cells contain abundant mucin vacuoles in cytoplasm that attenuate and displace their nuclei. The nuclear membrane is irregular and sharply angulated and the nuclei reveal a coarse chromatin pattern with prominent nucleoli.
Fig. 2Histologic features of mucinous cystadenocarcinoma. (A) The tumor shows an abundant mucin pool in stroma with floating cell clusters. (B) The ductal carcinoma in situ is found in the form of small cysts, adjacent to the invasive carcinoma. The cysts are lined by a single layer of tall columnar mucinous cells with focal areas of micropapillary and small tufted structures, resembling those of the uterine endocervix. (C) The invasive cells are pleomorphic and contained mucin vacuoles in cytoplasm displacing atypical nuclei to the periphery. (D) Both the intracytoplasmic and extracytoplasmic mucin are stained by alcian blue.
Fig. 3Immunohistochemical staining of mucinous cystadenocarcinoma. The tumor cells are positive for cytekeratin 7 (A) and negative for cytokeratin 20 (B). The hormone receptors, estrogen receptor and progesterone receptor, are negative and the c-erbB2 is 2-positive (C). The tumor cells are positive for mucin (MUC) 1 (D) along the cytoplasmic membrane and negative for MUC2 (E). Mucin of the intracytoplasm and stroma reveal positivity for MUC5 (F).
Table 1Clinical feature of mucinous cystadenocarcinoma in the breast
Table 2Immunohistochemical feature of mucinous cystadenocarcinoma in the breast
Table 3Comparison of mucin-producing tumors in the breast