Comparison of methods for checking surgical margins. Surgical margins of a cutaneous neoplasm can be evaluated by various combinations of three major types of sections: vertical (perpendicular), horizontal (parallel), and oblique (Mohs method). Vertical sections may run transversely through tumor (breadloaf method), longitudinally through tumor (breadloaf-cross method), or peripheral to the tumor. The peripheral (perimeter) sectioning methods are the only methods that can evaluate almost 100% of the margin, but they have the disadvantage of not showing the relationship of the tumor to its margin, which can be seen clearly with the vertical transverse sections. Seven methods of checking surgical margins are compared and contrasted. None of these is judged to be perfect or best. 