What happened, in summary

A 56-year-old woman developed leg swelling and worsening shortness of breath over 2 months. Testing showed severe pulmonary hypertension, but CT did not show a conventional blood clot or a visible lung tumor. Enlarged para-aortic lymph nodes prompted early gastrointestinal evaluation, and endoscopy found gastric cancer. Biopsy showed poorly differentiated gastric adenocarcinoma with signet-ring cells.

Her breathing and circulation deteriorated rapidly, and the clinical picture was considered pulmonary tumor thrombotic microangiopathy, a rare complication in which cancer cells affect the small blood vessels of the lungs. Oxygen, dobutamine and bosentan did not improve her pulmonary pressures. She then received off-label imatinib. Within 5 days, her pulmonary artery pressure normalized and her shortness of breath resolved.

She was discharged and continued gastric cancer chemotherapy that included oxaliplatin. The pulmonary hypertension did not recur. Despite that improvement, the gastric cancer later spread systemically, and she died 7 months after the pulmonary vascular presentation.