A 90-year-old man with a history of left upper lobe pulmonary nodule on prior imaging presented with dark tarry stools, fatigue and syncope. He had not had an EGD or colonoscopy done in about 10 yrs. Five months prior to this presentation, a 2.4 cm left upper lobe pulmonary nodule suspicious for neoplasm was incidentally found on CXR. Follow-up surveillance CT scans showed multiple hepatic nodular hypodensities consistent with metastatic lesions confirmed by (FDG-PET)/CT. His social history is notable for a remote history of smoking.
On physical exam, the patient had pale conjunctivae and dry mucous membranes. FOBT was positive on rectal exam. His labs showed a hemoglobin of 5.7 and a hematocrit of 18.1. He received 2 units of pRBC and was started on a proton pump inhibitor (PPI) drip. His esophagogastroduodenoscopy (EGD) showed a non-obstructing non-bleeding cratered gastric ulcer of significant severity at the greater curvature of the gastric body. A gastric ulcer biopsy showed metastatic squamous carcinoma involving the base of the gastric mucosa without surface involvement on H&E stain. Given his extremely poor functional status, he was referred to palliative care and passed away 54 days after his presentation with GI bleed. The family declined an autopsy.
Discussion:
Lung cancer has a predilection to widely metastasize to the liver, bone, brain and adrenal glands. Metastasis of primary lung tumors to the gastrointestinal tract is infrequent, with only sporadic cases reported. The incidence of symptomatic gastrointestinal metastases is extremely rare. To the best of our knowledge, 20 cases in the English literature have reported symptomatic gastric metastasis of lung cancer diagnosed by endoscopic biopsy (Table 1).
Our case, along with the majority of gastric metastases reported in literature support the case of Squamous cell carcinoma also being the most common type of lung cancer metastasizing to the stomach. Surprisingly, the second most common type is adenocarcinoma; a difficult pathological diagnosis to establish given the glandular epithelium of the stomach.
From an epidemiological point of view, the vast majority of gastric metastases present in male smokers. Not a single case reported a non-smoker; although some cases did not report a smoking status. Interestingly, our case occurred in the eldest individual so far (age range:45-90).
Metastatic spread to the GI system can present with symptoms including abdominal pain, GI bleeding, bowel obstruction, peritonitis and perforation. The two most common symptoms associated with gastric metastasis in our review were melena and epigastric pain.
The most common site of metastasis appears to be the gastric corpus; while our case’s site of metastasis was the greater curvature. The higher prevalence of GI metastases found on autopsies compared to the reported cases diagnosed by endoscopy suggests metastasis to GI might be a late event in the pathogenesis. The presence of other sites of metastases in our case and most of the literature supports this hypothesis.
Conclusions:
Gastric metastasis of lung tumors is very rare, but should be considered in patients with known lung masses presenting with melena. Additionally, we find gastric metastases of lung tumors to have a predilection to occur in male smokers with the most common type of tumor likely to be squamous cell carcinoma. The most common presentations are epigastric pain and melena.