We aimed to test this hypothesis in thymectomy patients with and without myasthenia gravis (MG).

The thymus is necessary to maintain immune competence and overall health, recently it was shown that thymic removal could potentially disrupt these functions.

This retrospective study analyzed clinical, laboratory, and radiological data from January 1, 2010, to November 30, 2023. Patients were grouped into MG thymectomy, non-MG thymectomy, and thoracoscopic surgery without thymectomy.

We identified a total of 178 patients (n=41 MG, n=65 non-MG, n=72 no thymectomy). MG-thymectomy group median age was 45.6 (range: 22-79 years) versus 59.8 years (range: 19-85) in the no-MG group; p<0.001. The median follow-up time was 5.5 and 3.9 years (range:1-10 years; P=0.13) respectively. Thymic mass was detected with chest CT in 56% (23/41) of the MG cohort and in all the non-MG cohort. Thymic pathology in MG group showed normal/fat atrophic thymus in 37.7% (13/41), hyperplasia in 26.8% (11/41), thymic cyst 2.4% (1/41), invasive thymoma 4.9% (2/41), or malignant 34.2% (14/41).  Thymic pathology in non-MG group reports showed hyperplasia, fat or normal thymus in 16.9% (11/65) malignant thymoma in 52.3% (34/65) and 7.7% (5/65) with malignant thymic carcinoma or squamous carcinoma 1.5% (1/65). Death occurred in 13.8% (9/65) of the non-MG group (median death age = 71.7 years) and no deaths in the MG group (P<0.001). Autoimmune diseases prevalence was similar between groups (0/41 in non-MG, 3/65 in MG; P=0.16). Surgery-associated complications showed no significant difference between the two treatment groups over a period of 3 years

Thymic removal correlated with higher mortality in non-MG patients, but not in patients with MG who show a lower incidence of all-cause mortality. The data supports the hypothesis that thymectomy in MG patients improved outcome and extends previous studies in non-MG cohort showing thymectomy increase mortality.