few months. Pulse was 86/min, BP 110/70 mmHg, soft ejection systolic murmur at precordium. Systemic exam revealed no abnormality. Routine lab studies showed no significant abnormality. Chest X-ray showed cardiomegaly with mediastinal mass.

On CECT thorax, a large heterogeneously enhancing solid cystic mass, 9.6 × 15.6 × 11.0 cm, was seen in anterior mediastinum anterior to great vessels and left paracardiac region. It showed smooth margin with curvilinear fine calcification and small calcified focus within the mass. Few conglomerate prevascular and right upper paratracheal bulky lymph nodes were noted. The mass was reported as germ cell tumor and biopsy was suggested. Histopathology revealed type B3 thymoma or epithelial thymoma, or well-differentiated thymic carcinoma.

About 10-14% of all thymomas are carcinoma; the 20 years survival rate is 40%. Association with associated myasthenia gravis is seen in 46% (our patient also presented with clinical features of myasthenia gravis). Patient was advised optimization of medical treatment for myasthenia gravis before surgery by using cholinesterase inhibitors.

Final diagnosis: Thymoma with RVOT obstruction.