This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
Signet-ring cells are found in which type of breast cancer NOT RELATED- GYN 
Select and explain. 
A. Papillary carcinoma, B. Tubular carcinoma, C. Invasive ductal carcinoma, D. Invasive lobular carcinoma
D: Invasive lobular carcinoma
Answer: D: Invasive lobular carcinoma 
Explanation: Invasive lobular carcinoma accounts for 10% of breast cancers. The histopathologic features of this cancer include small cells with rounded nuclei, inconspicuous nucleoli, and scant cytoplasm. Special stains may confirm the presence of intracytoplasmic mucin, which may displace the nucleus (signet-ring cell carcinoma).