Ductal breast carcinoma vs Lobular breast carcinoma
How to tell Ductal breast carcinoma and Lobular breast carcinoma apart when a board question makes them look alike.
Ductal is mass-forming duct disease; lobular is E-cadherin loss with single-file dyscohesive cells and multifocal subtle disease.
Side by side
Ductal carcinoma often forms a palpable mass and includes ductal carcinoma in situ with malignant cells filling ducts and possible comedo necrosis.
Lobular carcinoma often presents as subtle thickening or multifocal/bilateral disease and shows dyscohesive cells in single-file pattern due to E-cadherin loss.
Ductal carcinoma arises from ductal epithelium and tends to form cohesive masses.
Lobular carcinoma loses E-cadherin-mediated adhesion, causing discohesive infiltration through stroma.
DCIS calcifications, comedo necrosis, invasive ductal mass, and cohesive duct-forming malignant cells support ductal carcinoma.
Single-file cells, loss of E-cadherin, signet-ring-like cells, and multifocality support lobular carcinoma.
The trap
Both are invasive breast cancers, but the histology and clinical behavior differ in ways that change imaging and surgical planning. Invasive DUCTAL carcinoma (about 75 percent of invasive breast cancers) forms a discrete palpable mass with cohesive duct-forming malignant cells; mammography shows a stellate mass with microcalcifications; behaves like a typical solid tumor. Invasive LOBULAR carcinoma (about 10 to 15 percent) has LOSS OF E-CADHERIN (CDH1 mutation) so the cells cannot stay together they infiltrate as single-file lines (Indian file pattern) with bull's-eye targetoid appearance around ducts; imaging often shows subtle asymmetric thickening rather than a discrete mass, with higher rates of multifocal and bilateral disease and a higher likelihood of metastasis to peritoneum, retroperitoneum, ovaries, and GI tract.
The repair move
For breast carcinoma subtype, look for duct formation or single-file E-cadherin-loss infiltration.
Try a free question
CoreA 54-year-old woman has a screening mammogram showing pleomorphic clustered microcalcifications in the right upper outer quadrant without a discrete mass. Stereotactic core biopsy shows malignant epithelial cells filling and distending ducts with central comedo-type necrosis but no invasion through the basement membrane. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Ductal carcinoma in situ. Ductal carcinoma in situ (DCIS) shows malignant ductal cells confined by basement membrane; comedo-type necrosis and pleomorphic microcalcifications are classic imaging and histologic findings.
Why the other choices are tempting
- B. Invasive lobular carcinoma shows single-file infiltration past the basement membrane, not preserved ductal architecture with central necrosis.
- C. Lobular carcinoma in situ shows expansion of lobules by small uniform cells without ductal involvement.
- D. Atypical ductal hyperplasia has fewer atypical features and does not fill ducts with comedo necrosis.
- E. Paget disease of the nipple has malignant cells in the epidermis of the nipple, not within breast ducts.
Flashcards
Tap a card to flip it.
What histology supports lobular carcinoma?
Single-file dyscohesive cells support lobular carcinoma.
What molecule is lost in lobular carcinoma?
E-cadherin is lost in lobular carcinoma.
Quick answers
What is the fastest way to tell Ductal breast carcinoma from Lobular breast carcinoma?
Ductal is mass-forming duct disease; lobular is E-cadherin loss with single-file dyscohesive cells and multifocal subtle disease.
What is the key clue for Ductal breast carcinoma?
Ductal carcinoma often forms a palpable mass and includes ductal carcinoma in situ with malignant cells filling ducts and possible comedo necrosis.
What is the key clue for Lobular breast carcinoma?
Lobular carcinoma often presents as subtle thickening or multifocal/bilateral disease and shows dyscohesive cells in single-file pattern due to E-cadherin loss.
What is the common trap with Ductal breast carcinoma vs Lobular breast carcinoma?
Both are invasive breast cancers, but the histology and clinical behavior differ in ways that change imaging and surgical planning. Invasive DUCTAL carcinoma (about 75 percent of invasive breast cancers) forms a discrete palpable mass with cohesive duct-forming malignant cells; mammography shows a stellate mass with microcalcifications; behaves like a typical solid tumor. Invasive LOBULAR carcinoma (about 10 to 15 percent) has LOSS OF E-CADHERIN (CDH1 mutation) so the cells cannot stay together they infiltrate as single-file lines (Indian file pattern) with bull's-eye targetoid appearance around ducts; imaging often shows subtle asymmetric thickening rather than a discrete mass, with higher rates of multifocal and bilateral disease and a higher likelihood of metastasis to peritoneum, retroperitoneum, ovaries, and GI tract.