This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
E-cadherin mutation is seen in metastasis of which type of breast carcinoma 
Select and explain. 
A. Infiltrative ductal Ca, B. Lobular Ca, C. Metaplastic Ca, D. Medullary Ca
B: Lobular Ca
Answer: B: Lobular Ca 
Explanation: Answer- B. Lobular CaMutation in gene encoding for E-cadherin (CDH-I) is associated with gastric carcinoma and lobular breast carcinoma.Detachment of tumor cells is thefrst step tn metastasis. Normally cells are glued to each other by adhesion moleculesE-cadherin. Normal function of E-cadherin is dependent on catenins that helps in linkage of cytoskeleton to E-cadherin.Down regulation of expression of either E cadherins or catenins results looseining of cells that helps ln metastasis.