This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
Paget's disease of the nipple is 
Select and explain. 
A. Superficial manifestation of underlying breast Ca, B. Galactocele, C. Eczema, D. All of the above
A: Superficial manifestation of underlying breast Ca
Answer: A: Superficial manifestation of underlying breast Ca 
Explanation: Paget's disease of the nipple is superficial manifestation of an intraductal breast carcinoma. The malignancy spreads within the duct up to the skin of the nipple and down into the substance of the breast. It mimics eczema of nipple and areola. In Paget's disease, there is a hard nodule just underneath the areola, which later ulcerates and causes destruction of nipple. Histologically, it contains large, ovoid, clear Paget's cells with malignant features. Paget's hyperchromatic cells are located in rete pegs of epidermis containing intracellular mucopolysaccharides as clear halo in cytosol. Reference : page 533 SRB's manual of surgery 5th edition