Infiltrating Lobular Carcinoma of the Breast
Definition
- Infiltrating carcinoma typically composed of uniform cells often arranged in a linear infiltrative pattern
Diagnostic Criteria
- Classic type
- Uniform cells with grade I cytologic features
- Signet ring differentiation may be prominent
- Nuclear molding is often prominent
- Linear infiltrative pattern
- Rows of cells no more than one or two cells wide
- Frequent target-like concentric pattern around ducts
- Poorly cohesive cells
- E-cadherin negative
- Uniform cells with grade I cytologic features
- Pleomorphic variant
- Larger pleomorphic cells with grade III nuclei
- Irregular nuclearl membranes, prominent nucleoli
- Frequently with abundant eosinophilic cytoplasm
- Larger pleomorphic cells with grade III nuclei
- Tubulolobular carcinoma is considered by some to be a variant of lobular carcinoma
- Alveolar variant
- Classic grade I cytologic features
- Rounded groups of cells
- Solid variant
- Classic grade I cytologic features
- Groups or trabeculae >2 cells thick infiltrate between collagen bundles
- Signet ring variant
- Architectural and cytologic features of lobular carcinoma
- >20% signet ring differentiation
- Mucin positive vacuoles
Richard L Kempson MD
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting, last update:: 5/1/06, 12/13/14