Persistent type 2 respiratory failure on background of advanced thymoma with lung metastases.

We report a patient in her 60s with history of end-stage thymoma with bilateral lung metastases on palliative chemotherapy presented to the hospital with sudden shortness of breath initially treated for probable pulmonary embolism (PE) pending CT of the pulmonary arteries which was subsequently negative for PE. During this admission, she developed transient right-sided facial droop and slurred speech which resolved spontaneously; however, the patient became unresponsive and desaturated with severe decompensated type 2 respiratory failure. Patient was supported with non-invasive ventilation (biphasic positive airway pressure) for few days. Myasthenia gravis was suspected due to clinical features and confirmed by the high titre of acetylcholine receptor antibody titre.