Stage IV gastric adenocarcinoma first detected through an appendiceal metastasis

What happened, in summary

A 79-year-old man came to the emergency department after 2 months of weakness, poor appetite, drowsiness and mood changes. He became hypotensive and was initially treated for suspected sepsis. CT later found an abscess near the right iliac muscle and an inflamed, dilated appendix. The abscess was drained and he received antibiotics, with improvement in his blood pressure and mental status.

After 6 weeks of treatment for presumed appendiceal phlegmon, he underwent interval appendectomy. Pathology unexpectedly showed adenocarcinoma involving the appendiceal wall and suggested a gastrointestinal origin. Colonoscopy did not identify a primary colorectal cancer. Upper endoscopy then revealed an infiltrative, circumferential tumor narrowing the body of the stomach. Gastric biopsies showed well-differentiated adenocarcinoma.

The appendiceal involvement represented distant spread, and the gastric cancer was classified as Stage IV. He was referred to oncology, where his age and physical condition were considered in choosing treatment. Oral capecitabine chemotherapy was started. The case illustrates an unusual presentation in which metastatic gastric cancer was first uncovered through disease involving the appendix rather than through typical stomach symptoms.