A 40-year-old female presented to the OPD with cough, mild chest pain and mild hoarseness of voice. Some respiratory pathology was suspected. Chest x -ray MRI chest was also done. Which of the following RNS findings should be suspected in the above patient: -

This is a case of thymoma. Chest x-ray shows soft tissue density projecting to the left of the mediastinum. The distal pa of the arch and proximal descending aoa can be seen as separate suggesting it is located anterior to these structures. MRI confirms the presence of an anterior mediastinal mass without convincing macroscopic invasion. Thymomas are frequently associated with the neuromuscular disorder myasthenia gravis. Thymoma is found in 20% of patients with myasthenia gravis. Image A shows normal response. Image B shows decremental response - seen in myasthenia gravis patients. Image C shows incremental response - seen lambe Eaton syndrome patients.