Patients with SDHB-related PHEO or PGL did not differ in the time to the development of metastasis (P = 0.54), and the probability of a 5-year metastasis-free interval among those without synchronous metastasis was similar (48.2% for PGL and 55.0% for PHEO).As described in Material and Methods, we used an ROC curve to establish an optimal cut-off size of the primary tumor in regards to the development of any metastases; the primary tumor size of 4.5 cm was the size that maximized the sum of the sensitivity and specificity to develop metastatic disease. Here, SDHB is linked to metastatic neoplasm.