Tubulolobular Carcinoma of the Breast

Differential Diagnosis

Tubular Carcinoma	Tubulolobular Carcinoma
90% pure tubular pattern	Mixed tubular and lobular patterns
Stellate infiltrating architecture	Linear infiltrative pattern, frequently concentric

Both are typically E-cadherin positive

Tubulolobular Carcinoma	Infiltrating Lobular Carcinoma
Contains a tubular component	Uniform single file pattern
E-cadherin positive	E-cadherin negative

Some consider tubulolobular carcinoma to be a variant of lobular carcinoma

Breast vs. other origin in carcinoma of unknown primary