POMC and thymoma: These results indicate that POMC was significantly associated with a more advanced MGFA stage (OR = 2.43, 95% CI: 1.43–4.14, P = 0.001), POA (OR = 2.18, 95% CI: 1.30–3.66, P = 0.003), preoperative myasthenic crisis (OR = 1.93, 95% CI: 1.05–3.53, P = 0.033), high daily dose (<180 mg) of PYR (OR = 6.05, 95% CI: 3.52–10.41, P < 0.001), thymoma (OR = 2.10, 95% CI: 1.23–3.59, P = 0.007), an ectopic thymus (OR = 1.78, 95% CI: 1.06–3.01, P = 0.03), and postoperative pneumonia (OR = 4.68, 95% CI 2.50–8.76, P < 0.001).