Magnetic resonance imaging findings of carcinoma arising from anal fistula: A retrospective study in a single institution

Table 3 Summary of magnetic resonance imaging findings in carcinoma arising from anal fistula

Pathology	Location	Shape	Maximum diameter of lesion (cm)	Margin and capsule	Signal characteristics			Fistula between mass and anus	Enhancement of tumor	Enhancement and signal on FS-T2WI of peritumoral areas	Regional lymph nodes
					FS-T2WI	DWI	ADC				Short axis enlargement	Morphology	Signal intensity(FS-T2WI/DWI)	Enhancement
M	Left	Multilocular, cauliflower-like	3.6	Unclear; Yes	Markedly hyperintense	Slightly hyperintense	Hyperintense	Yes	Progressive mesh-like enhancement	No	Yes	Change	Heterogeneous; hyperintense	Yes
M	Right	Multilocular, cauliflower-like	4.7	Clear; Yes	Markedly hyperintense	Hyperintense	Local hypointense	Yes	__	__	Yes	Normal	Heterogeneous; normal	-
M	Left	Round	4.1	Unclear; No	Slightly hyperintense	__	__	Yes	__	__	Yes	Change	Heterogeneous; -	-
M	Across the midline	Multilocular, cauliflower-like	10.6	Unclear; Yes	Markedly hyperintense	__	__	Yes	__	__	Yes	Change	Heterogeneous; -	-
M	Left	Multilocular, cauliflower-like	12.4	Unclear; Yes	Markedly hyperintense	__	__	Yes	__	__	No	Change	Heterogeneous-us; -	-
M	Left	Band-like	3.4	Unclear; No	Hyperintense	__	__	Yes	__	__	No	Change	Heterogeneous-us; -	-
M	Left	Multilocular, cauliflower-like	4.3	Unclear; Yes	Markedly hyperintense	Hyperintense	Local hypointense	Yes	Progressive mesh-like enhancement	Yes	No	Normal	Normal; normal	No
M	Across the midline	Multilocular, cauliflower-like	6.0	Unclear; Yes	Markedly hyperintense	Hyperintense	Local hypointense	Yes	Progressive mesh-like enhancement	Yes	No	Normal	Heterogeneous-us; normal	No
A	Left	Oval	3.7	Unclear; No	Slightly hyperintense	Hyperintense	Hypointense	No	Persistent heterogeneous enhancement	Yes	Yes	Change	Heterogeneous-us; hyperintense	Yes
A	Right	Oval	4.0	Unclear; Yes	Hyperintense	__	__	Yes	Persistent heterogeneous enhancement	Yes	Yes	Change	Heterogeneous-us; -	Yes

FS-T2WI: Fat-suppressed T2-weighted magnetic resonance imaging; DWI: Diffusion-weighted imaging; ADC: Apparent diffusion coefficient; M: Mucinous adenocarcinoma; A: Adenocarcinoma.