Table 1 Univariate and multivariate analysis (OR) of some histopathological features of nodular melanoma (NM) versus superficial spreading melanomas (SSMs)

Thickness (mm)

 ≤ 1.00

9 (9.4)

72 (61.0)

1^b

1^b

 1.01–2.00

24 (25.0)

22 (18.6)

8.73 (3.54–21.52)

7.22 (2.73–19.05)

 2.01–4.00

44 (45.8)

22 (16.6)

16.00 (6.76–37.87)

7.04 (2.54–19.56)

 > 4.00

19 (19.8)

2 (1.7)

76.00 (15.14–381.51)

51.78 (5.65–474.86)

 χ² ₁ trend: p value

p < 0.0001

p < 0.0001

Ulceration

 Absent

46 (47.9)

96 (81.4)

1^b

1^b

 Present

43 (44.8)

18 (15.2)

4.98 (2.59–9.57)

1.56 (0.67–3.62)

 Unknown

7 (7.3)

4 (3.4)

 χ² ₁: p value

p < 0.0001

p = 0.3066

Regression

 Absent

65 (67.7)

67 (56.8)

1^b

1^b

 Present

24 (25.0)

46 (39.0)

0.54 (0.30–0.98)

0.55 (0.25–1.22)

 Unknown

7 (7.3)

5 (4.2)

 χ² ₁: p value

p = 0.0428

p = 0.1393

Mitoses (n/mm²)

 ≤ 2

31 (32.3)

86 (72.9)

1^b

1^b

 3–5

24 (25.0)

14 (11.9)

4.76 (2.19–10.34)

2.62 (1.01–6.83)

 > 5

35 (36.5)

11 (9.3)

8.83 (4.00–19.49)

4.87 (1.77–13.40)

 Unknown

6 (6.2)

7 (5.9)

 χ² ₁ trend: p value

p < 0.0001

p = 0.0015

TIL^d

 Absent

29 (30.2)

34 (28.8)

1^b

 Brisk

14 (14.6)

27 (22.9)

0.61 (0.27–1.37)

 Non-Brisk

46 (47.9)

48 (40.7)

1.12 (0.59–2.13)

 Unknown

7 (7.3)

9 (7.6)

 χ² ₁ trend: p value

p = 0.6174