Is resection of a thymoma WHO A indicated in the absence of myasthenia gravis?

Occasionally, there is uncertainty if low grade thymomas (WHO A) without concomitant myasthenia gravis (MG) require resection, as in the following case. In a 72yo Caucasian female, with a previous history of subarachnoidal bleeding due to rupture of an intracranial right-sided carotid artery aneurysm, which required clipping, a mediastinal mass was detected upon routine pre-operative X-ray of the lung. Computed-tomography-guided biopsy revealed a thymoma WHO A. Resection of the thymoma was recommended but carried out not earlier than half a year after tumour detection, arguing that the dignity of the tumour does not require immediate surgical intervention. Arguments for immediate resection of a thymoma WHO A, however, are that needle biopsies allow assessment only of a small part of the tumor, that the dignity according to the Masaoka classification can often not be assessed by biopsy alone without complete resection of the tumor, that thymoma is occasionally associated with malignancy, that thymoma WHO A theoretically might change to more abnormal histological grades or may progress making the resection more complicated at a higher stage, and that most national and international organizations recommend resection of a thymoma, disregarding its histological dignity. In conclusion a thymoma WHO A requires complete surgical resection, irrespective if the thymoma is accompanied by MG or not.