Massive upper gastrointestinal bleeding is a life-threatening emergency. Hematological malignancies are very rare causes of this type of bleeding. In this case, we present a gastric diffuse large B-cell lymphoma (DLBCL) with a massive upper gastrointestinal system bleeding, causing shock and an only option of radiotherapy at this emergency setting. 
A 52-year-old male patient was admitted to emergency clinic with hematemesis and hematochezia. In physical examination patient was confused, pale and sweaty; his vital signs were unstable with a heart rate of 150 per minute and a blood pressure of 60/30 mmHg. His hemoglobin (Hb) level was found 4.71 g/dL. 

A resuscitation measures were started, first gasimetry showed severe metabolic acidosis (pH: 7,420; pCO2: 9,0 mmHg; pO2: 190,0 mmHg, HCO3: 5,8, Lac >15,0 mmol/L). He was intubated and ventilated. After adequate volume expansion (crystalloids and blood products), a noradrenalin was started. An attempt of upper gastric endoscopy was unsuccessful as a tumor occupied all gastric lumen, and there was no surgical solution due to extension of tumor lesions. A desperate option was proposed – radiotherapy session. Two hours after he performed a three dimensional (3D) conformational radiotherapy with a total dose of 8Gy. Immediately after, he started to respond positively to blood transfusion with Hb raise and improving of hemodynamic stability. A noradrenalin was stopped 12h after and patient admitted to ICU. Next day he started chemotherapy (Cyclophosphamide, Doxorubicin, Vincristine and Prednisone) and five days later was extubated and discharged from ICU to the oncologic ward.
Although not listed as a common cause of massive gastrointestinal bleeding DLBCL can cause life-threatening situations mostly because of its malignant nature. However, in most cases a bleeding cancer responses to radiotherapy is not immediate, but in some desperate cases,   an external beam radiation therapy might stop bleeding and save lives, when applied in emergency setting.

3 - Radiotherapy as an only saving option for oncologic patient in hemorrhagic shock