Table 4. Distribution of lymphatic levels affected in patients with known regional metastases.

Category a		Ipsilateral				Contralateral
		I–IV	V	RP	PAR	Any
Histologic type
Low risk		100.0	0.0	0.0	0.0	0.0 b
Moderate risk		78.6	17.9	14.3	14.3	17.9 b
High risk		89.7	13.8	10.3	13.8	55.2 b
Location of primary
Midline		94.7	10.5	10.5 b	10.5	47.4
Ethmoid complex		81.8	0.0	18.2 b	27.3	27.3
Maxillary complex		80.0	15.0	0.0 b	10.0	20.0
Frontal/sphenoid		66.7	33.3	0.0 b	0.0	66.7
Other nasal cavity		83.3	50.0	50.0 b	16.7	50.0
Invasion c
Skull base	Yes	90.0	16.7	20.0	13.3	53.3 b
	No	79.3	13.8	3.4	13.8	17.2 b
Dura	Yes	90.9	13.6	18.2	13.6	54.5 b
	No	81.1	16.2	8.1	13.5	24.3 b
Pterygoid space	Yes	100.0	42.9	42.9 b	14.3	42.9
	No	82.7	11.5	7.7 b	13.5	34.6
Facial soft tissue	Yes	33.3 b	16.7	0.0	50.0 b	16.7
	No	90.6 b	15.1	13.2	9.4 b	37.7

Abbreviations: I–IV, levels I to IV of the lateral neck; V, level V of the lateral neck; Any, any contralateral nodes; PAR, parotid; RP, retropharynx.

Note : Within a certain category, the values in this table represent how often (%) a regional basin was affected in patients who had known regional metastases. Rows do not sum to 100% due to patients having metastases in multiple lymphatic basins.

^aCategories also included in statistical analysis but not reported in this table due to nonsignificant findings: histologic grade of tumor and T-stage.

^b p  < 0.05 by Fisher's exact test.

^cStatistical testing for the invasion category is a comparison between those with and without invasion into the applicable structure. Testing was also completed for invasion of the orbit, brain, infratemporal fossa, pterygopalatine fossa, nasopharynx, and palate, and no significant differences were identified.