Malignant Breast Aspirate

Cellularity

Cells

Pleomorphism

Infiltrating Ductal Carcinoma

• Sheets or cords with abundant single tumor cells;

• Prominent atypia;

• May have marked stromal fibrosis;

• Fine to coarse calcification;

• Mucin positive, especially intracytoplasmic mucin, lipid vacuoles.

• Often multicentric and bilateral;
• Monomorphic, moderate cellularity, with small isolated cells and a few dyshesive small groups;
• Small angular cells (8-12um) with small to moderate cytoplasm and relatively defined cell borders;
• Cytoplasmic vacuoles common, intracytoplasmic lumens common;
• Small round to angular eccentric nuclei with slightly molding and irregular nuclear membrane;
• Fine to granular chromatin with minimal hyperchromasia and one or two small nucleoli;
• Sparse or absent naked bipolar nuclei.

Ductal Carcinoma In Situ

• Compared with infiltrating ductal carcinoma, DCIS has less atypical cells, less atypia, less pleomorphism, but has more cohesive, more orderly, more naked bipolar nuclei and more benign component.

Medullary Carcinoma

• Often presents as a soft, round, mobile and well-defined mass in younger patient;

• Relatively good prognosis;

• Very cellular, single cells and loose, syncitial aggregates, with no or little gland formation and no mucin;

• Tumor cells are large, highly pleomorphic. Intact cells have a delicate cytoplasm with indistinct cell borders;

•  Many naked often distorted tumor cells;

• Large pleomorphic nuclei with irregular membranes, highly clumped chromatin and prominent nucleoli;

• May show marked mitoses and necrosis;

• Prominent lymphocyte and plasma cell infiltration.

Colloid Carcinoma

• Large, well-defined tumor with a soft, jelly-like consistency. Very good prognosis;

• Islands of tumor cells floating in a mucin pool;

• Tumor cells often in relatively cohesive sheets, balls or acini;

• Relatively monotonous and may show deceptively bland;

• Relatively uniform nuclei in size and shape with fine chromatin and inconspicuous nucleoli;

• No or rare signet-ring cells;

• Differential diagnosis: fibroadenoma with mucoid degeneration, benign papilloma, benign mucocele-like lesions and cystic hypersecretory duct carcinomas.

Tubular Carcinoma

• Small tumor, often multicentric and bilateral, good prognosis;

• Cellular, predominant cohesive clusters with sparse single cells

• Rigid, angular or twisted tubules with a central core of lumen, and glands with pointed, arrowed outlines;

• Well-differentiated tumor cells with cytological bland; focal atypia often present;

• Minimal nuclear enlargement and pleomorphism; often irregular nuclear membrane;

• Fine chromatin with small nucleoli;

• Intracytoplasmic lumens present;

• Sparse or absent naked bipolar nuclei;

• Differential diagnosis: fibroadenoma, papilloma, fibrocystic changes with hyperplasia, adenosis with radical scar.

Apocrine Carcinoma

• Abundant large malignant apocrine cells; many naked tumor cells;

• Abundant finely granular cytoplasm;

• Round to irregular eccentric nuclei with marked atypia;

• Irregular thick nuclear membrane with coarse irregular chromatin and prominent nucleoli;

• Large intracytoplasmic hyaline globules;

• May show prominent necrosis.

Reference

• The art and science of cytopathology. Richard M Demay, MD. 1996