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: Surgery
True about Sentinel Lymph node biospy ? 
Select and explain. 
A. Special OT is requried, B. Blue dyes injected, C. Contraindicated if axillary LN is involved, D. All
B: Blue dyes injected
Answer: B: Blue dyes injected 
Explanation: Ans. is 'b' i.e. Blue dyes injected No special OT is required, SLN biopsy is usually done intraoperatively by using isosulphan blue dye (lymphazurin) or radioactive colloid. Accuracy in detection of SLN is best when both the methods are combined. When radioactive colloid is used, the SLN is detected by a gamma-camera. The blue dye colours the afferent lymphatics and the SLN, hence aids in the identification SLN Biopsy (for breast ca) is contraindicated in : palpable lymphadenopathy prior axillary surgery, chemotherapy or radiation therapy multifocal breast cancers