Occult gastric cancer manifested by progressive shortness of breath in a young adult.

We have reported a case of occult, diffuse gastric cancer in a young adult with progressive shortness of breath and bilateral pulmonary interstitial infiltrates. Progressive shortness of breath may be the first or only manifestation of occult gastric cancer caused by either lymphangitic carcinomatosis or microscopic tumor emboli to the lungs. Widespread recognition of this syndrome, a high index of suspicion, and prompt lung biopsy are necessary to make the correct diagnosis. With progress in chemotherapy for malignant diseases, early diagnosis and specific treatment may improve the prognosis of this condition.