An Extemly Rare Case of Left Atrium and Right Pulmonary Vein Leiomyosarcoma.

We report a case of a 43-year-old female, presented with complaints of breathlessness for 1 month and had three episodes of syncopal attacks in the past two months. On clinical evaluation, bilateral pedal oedema was noticed. Echo cardiogram revealed large left atrial blood clot measuring 5.7x4.3x4.3 cm. Ultrasound whole abdomen was normal. We received an excised mass with right pulmonary vein end arterectomy speciemen. Histopathology of the mass revealed characteristic features of leiomyosarcoma with grade III, according to FNCCS grading system. The tumour was consistent with substantial amount of poorly differentiated fasicles of pleomorphic spindle cells and brisk atypical mitosis, with marked necrosis. Immunohistochemistry revealed the tumour cells in strong diffuse cytoplasmic positive for smooth muscle actin and Ki-67 showed 15-20% of tumour cells postivity. The prognosis depends on the individual tumour origin for individual site, size of tumour and depth of tumour than histological features. Pulmonary venous leiomyosarcomas were assumed to be misinterpretation of left atrial leiomyosarcomas with growth of the tumour into pulmonary vein lumen. We report this case in view of its extreme rarity.