Primary lung sarcoma with gastric metastasis and morphological divergence presenting as melena.

A 61-year-old man was admitted to the medical intensive care unit following a 2-week history of weakness, lightheadedness and melena resulting in an acute anaemia. Upper endoscopy revealed multiple large gastric masses without evidence of active bleeding. CT of the chest revealed a large right upper lobe mass with bony destruction of the third rib and invasion into the anterior chest wall and mediastinum, as well as a soft-tissue density in the left kidney. Biopsy and histopathological review of both pulmonary and gastric masses revealed two distinct sarcomatous malignancies that, while both from a primary lung source, differed in their morphology. Natural history and behaviour are not well understood in sarcomas due to their rarity, but abdominal metastasis is considered an uncommon event in the progression of the disease. Gastrointestinal bleeding as the presenting symptom of a primary lung sarcoma is an atypical finding with no previously reported cases.