Table 1.

Classifications of margins in soft tissue sarcomas.

Classification	MSTS [6]	AJCC [7]	UICC [9]	Tumor Clearance [2]	TMCC [10]	Margin Quality [6]
Description	Radical: all normal tissue involved anatomic compartment excised en-bloc	R0: tumor does not reach intact barrier or resection margins	R0: resection margin >1 mm	Metric distance from edge of tumor to inked surgical resection margin	Negative margins: tumor does not reach intact barrier or resection margins	Anatomic factors (the tissue composition of the margin)
-	Wide: histologically non-reactive normal tissue at margin	R1: Microscopic tumor contamination of margins or resection alongside pseudocapsule	R1: Resection margin < 1 mm	-	Unplanned positive margins	-
-	Marginal: pseudocapsule present at margin	R2: Macroscopic tumor contamination	R2: Macroscopic tumor contamination	-	Planned close but with an ultimately positive microscopic margin along a critical structure	-
-	Intralesional: Tumor present at margin	-	-	-	Positive margin after a tumor bed re-excision in patients treated initially with inadequate surgery elsewhere (“whoops procedure”)	-

AJCC: American Joint Committee on Cancer (R classification); MSTS: Muscoloskeletal Tumor Society; UICC: Union Against cancer; TMCC: Toronto Margin Context Classification.