Table 2.

Morphological and adverse histological features of malignant carotid body tumors.

Patient	Tumor size (cm)	Nodular lesion	Incomplete capsule	Nuclear atypia	Necrosis	Venous invasion	Nerve invasion	Tumor thrombus
Case 1	4 × 4 × 3.5	+	+	+	+	+	−	−
Case 2	3.7 × 3.6 × 4.2	+	+	−	+	+	+	−
Case 3	2.5 × 2.5 × 2	−	−	+	−	+	−	−
Case 4	11 × 9 × 5	+	+	+	+	+	+	+
Case 5	4.5 × 4 × 4	+	+	−	+	+	+	+
Case 6	5 × 3.5 × 3	+	+	+	+	+	+	+
Case 7	3 × 2.5 × 2.5	+	−	+	−	+	−	+
Case 8	5 × 5 × 3	+	+	−	−	+	−	−
Case 9	2.5 × 2.5 × 2	−	+	+	−	+	−	−
Case 10	13 × 10 × 9	+	+	+	+	+	+	+

+: present; −: absent.