When Pneumonia Isn't the Whole Story: A Diagnostic Challenge in Septic Shock.

Septic shock in immunocompromised patients typically arises from common infections but may coexist with unexpected findings that influence clinical reasoning and management. We report the case of a 77-year-old male patient with rheumatoid arthritis under chronic immunosuppressive therapy (low-dose corticosteroids and methotrexate), admitted to the intensive care unit with septic shock and multiorgan dysfunction. The clinical presentation at the emergency department, with two days of fever and productive cough, respiratory failure, and hypotension, was consistent with severe community-acquired pneumonia. This was confirmed by imaging, which showed right-lower-lobe pulmonary infiltrates and pleural effusion. However, the patient also described a seven-day history of diarrhea with mucus and blood, prompting further gastrointestinal investigation. Abdominopelvic CT revealed sigmoid diverticulosis and a thin, linear hyperdense structure embedded in the colonic wall. Flexible sigmoidoscopy confirmed the presence of a filiform foreign body, compatible with a fruit stem, approximately 3 cm in length, which was successfully removed. Although pneumonia was considered the primary source of septic shock, the gastrointestinal findings may have contributed to systemic inflammation in a vulnerable host. This case reinforces the need for a broad diagnostic evaluation in septic patients with overlapping symptoms and highlights the relevance of incidental findings in complex clinical contexts.