Solitary metachronous gastric metastasis from pulmonary adenocarcinoma: Report of a case

Abstract

Introduction: Gastric metastases from lung adenocarcinoma are rare and usually associated with disseminated disease. The great majority is asymptomatic and in few cases discovered during autopsy studies. Reports of single metachronous metastases during the lifetime are anecdotal. We describe a case of solitary gastric metastasis 5 years after lung surgery.

Presentation of case: A 68-year-old male submitted in 2006 to right lobectomy for lung adenocarcinoma was referred at Emergency Room department in 01/2011 because of chronic epigastric pain. Radiologic and endoscopic evaluation showed a bulky lesion inside the stomach, originating from the muscular layer, suspected for GIST. He underwent a subtotal gastrectomy and the pathologic examination revealed an undifferentiated adenocarcinoma, positive for Thyroid Transcriptional Factor-1, Cytokeratin 7, AE 1/3 and CEA, confirming the pulmonary origin.

Discussion: At the time of diagnosis about 50% of lung cancer are metastatic, with survival rates of 1% at 5-year. Gastric metastasis is very rare; autopsy studies report an incidence of 0.2-0.5%. They develop in the submucosa, usually without any symptom and the diagnosis is incidental during the staging of primary cancer or the follow-up. There are no guidelines about surgical treatment; however few cases of long-term survival following the operation were reported. Pathologic diagnosis is difficult, but the immunohistochemical staining helps to recognize the primary origin.

Conclusion: Solitary metachronous gastric metastasis from pulmonary adenocarcinoma is an exceptional event, but it could happen during the follow-up. It seems that a radical resection, in absence of systemic implants, might provide survival benefits in selected patients.