Which statement correctly differentiates multifocal and multicentric breast cancer?

Which statement correctly differentiates multifocal and multicentric breast cancer?

• A. Multifocal is cancer in different quadrants; multicentric is in the same quadrant
• B. Multifocal is a single tumor with satellite lesions; multicentric is multiple tumors within same duct
• C. Multifocal is cancer in more than one site within the same quadrant or ductal system; multicentric is cancer in different quadrants at least 5 cm apart
• D. Multifocal is cancer in one breast; multicentric is cancer in both breasts

Answer: (C)

The key idea is how multiple cancer foci are distributed inside the same breast. If there are several tumor foci within the same quadrant or within the same ductal system, that’s multifocal disease. If the tumors are in different quadrants and are separated by a substantial distance (commonly defined as at least 5 cm), that’s multicentric disease. This distinction matters for planning surgery and treatment. The statement you’re choosing says multifocal disease means multiple tumors within the same quadrant or ductal system, while multicentric disease means tumors in different quadrants at least 5 cm apart. That captures the standard distinction used in practice: same-area foci versus widely separated foci in the same breast. Other options mix up the location concepts or introduce bilateral disease, which isn’t how multifocal vs multicentric are defined. For example, having tumors in different breasts would be bilateral cancer, not a differentiation of multifocal versus multicentric within one breast.

The key idea is how multiple cancer foci are distributed inside the same breast. If there are several tumor foci within the same quadrant or within the same ductal system, that’s multifocal disease. If the tumors are in different quadrants and are separated by a substantial distance (commonly defined as at least 5 cm), that’s multicentric disease. This distinction matters for planning surgery and treatment.

The statement you’re choosing says multifocal disease means multiple tumors within the same quadrant or ductal system, while multicentric disease means tumors in different quadrants at least 5 cm apart. That captures the standard distinction used in practice: same-area foci versus widely separated foci in the same breast.

Other options mix up the location concepts or introduce bilateral disease, which isn’t how multifocal vs multicentric are defined. For example, having tumors in different breasts would be bilateral cancer, not a differentiation of multifocal versus multicentric within one breast.