Date Posted: June 10, 2026

Author/s: Maria Crisanta G. Villanueva, MD

Multiple primary tumors are rare with the prevalence of 0.734% to 11.7%. Detecting these tumors presents as a diagnostic dilemma which affects treatment and prognosis of these patients. This is a case of a 79-year-old, male with metachronous malignant lesions in the lung and stomach. He initially presented with non-productive cough, hematemesis, and a pulmonary mass upon chest X-ray. CT guided biopsy was done and showed pulmonary tuberculosis but the patient refused treatment. He later presented with melena in which an endoscopy revealed gastric ulcer and biopsy of gastric adenocarcinoma. Patient underwent laparoscopic subtotal gastrectomy with Roux-en-y Gastrojejunostomy. However, final histopathology of the stomach revealed gastric lymphoma. Chest CT scan showed increased size of the lung mass and biopsy done revealed lung adenocarcinoma. Patient is now diagnosed with metachronous double primary of non-small cell lung adenocarcinoma stage IIIA (pT4N0M0) and gastric lymphoma stage IIIA (pT4aN2M0). Patient underwent osimertinib chemotherapy for the non small cell lung adenocarcinoma and a pre-treatment phase of vincristine, then six cycles of CHOP-R (cyclophosphamide, doxurubicin, vincristine and prednisone with rituximab regimen) for the gastric lymphoma.

Keywords:
Large b-cell gastric lymphoma, pulmonary tuberculosis