Table 2.

Comparison of Clinical and Morphologic Findings in ROS1 and non-ROS1 fusion Spitz neoplasms

	All (n = 116)	Non-ROS1 vs ROS1
		Non-ROS1 (n = 99)	ROS1 (n = 17)	P
Clinical
Age, years				0.75
Mean	20.5	20.7	19.5
Range	1–65	1–65	3–58
Gender				0.80
Female	64	54	10
Male	52	45	7
Location				0.68
Head/Neck	23	19	4
Upper Extremity	33	30	3
Trunk	15	12	3
Lower Extremity	45	38	7
Histologic
Tumor Subtype				0.003
SN	29	20	9
AST	61	53	8
SM	26	26	0
Tumor depth, mm				0.32
Mean	2.04	1.88	2.93
Range	0.25–17.0	0.25–12.2	0.40–17.0
Tumor Diameter, mm				0.71
Mean	4.78	4.74	5.02
Range	0.69–16.5	0.69–16.50	2.90–14.0
Silhouette				0.16
Plaque	49	42	7
Wedge	31	29	2
Nodular	34	27	7
Polypoid	2	1	1
Cytology				0.17
Epithelioid	25	24	1
Spindled	30	26	4
Both	61	49	12
Nuclear Atypia				0.006
Mild	11	10	1
Moderate	74	58	16
Severe	31	31	0
Kamino body				0.025
Absent	89	80	9
Present	27	19	8
Pigmentation				0.10
Absent	66	52	14
Focal	29	27	2
Extensive	21	20	1
Maturation				0.044
Absent	18	18	0
Partial	26	19	7
Present	72	62	10
Ulceration				0.62
Absent	107	92	15
Present	9	7	2
Inflammatory Reaction				0.04
Absent	7	4	3
Non-Brisk	68	57	11
Brisk	41	38	3
Epidermal Hyperplasia				0.49
Absent	20	16	4
Present	96	83	13
Plexiform				0.42
Absent	73	64	9
Present	43	35	8
Epithelioid Sheet				0.04
Absent	94	77	17
Present	22	22	0
Pagetosis				0.32
Absent	93	81	12
Present	23	18	5
Cell Size				0.001
Small	21	20	1
Intermediate	65	49	16
Large	30	30	0
Nesting Adnexa				0.15
Absent	97	85	12
Present	19	14	5
Lobulated Nests				0.73
Absent	95	80	15
Present	21	19	2
Mitotic index (per mm2)				0.001
Mean	2.2	2.34	1.30
Range	0–20	0–20	0–4