A 78-year-old man in Culiacán, Mexico, spent weeks being treated for what looked like a stomach complaint. He had dull, continuous pain in the upper left side of his abdomen, black stools, bloating, and a 5-kilogram weight loss. He was given acid-suppressing medication and antibiotics and sent home.
He was, in fact, developing a ruptured appendix. His organs were arranged in a mirror image, a congenital condition called situs inversus totalis, and his appendix sat on the left side of his abdomen instead of the right. By the time surgeons opened him up, the appendix had perforated, his small bowel had a hole in it, and infection had seeded his liver.
The case was published in Cureus in November by a surgical team at the Regional Hospital "Dr. Manuel Cárdenas de la Vega," and it is an unusually clear illustration of how a single anatomical variant can dismantle the most familiar diagnostic script in emergency medicine.
Twenty Days of Pain in the Wrong Quadrant
The man had no history of chronic illness or prior surgery. His symptoms had already been running for 20 days when he first reached a hospital. Eight days after that discharge, he came back, still unwell.
Bloodwork was alarming rather than diagnostic: platelets at 700,000 per microliter, a prothrombin time of 23.7 seconds, and alkaline phosphatase at 310 units per liter, all well outside the reference range. Imaging then delivered the twist. Ultrasound and contrast-enhanced CT showed situs inversus totalis, an enlarged liver, a dilated portal vein at 16 millimeters, mild ascites, and a 140-cubic-centimeter collection around the liver.
After transfer to a tertiary hospital, doctors drained 400 cubic centimeters of pus, which grew Escherichia coli, and started ceftriaxone and metronidazole. He kept deteriorating. A follow-up CT finally showed inflammatory changes in the left iliac fossa, and surgery revealed the source: a necrotic appendix, perforated at the base of the cecum with a fecalith inside it, an inflammatory mass in the left lower abdomen, and a one-centimeter perforation of the ileum.
Surgeons removed 15 centimeters of ileum, the cecum, the ascending colon, and a third of the transverse colon, and created an ileostomy. Thirty-six days had passed since his first medical consultation. He recovered, was discharged after a week, and had bowel continuity restored a year later without complications. The published report frames the delay, not the anatomy, as the thing that nearly killed him.
A Mirror Image That Undoes the Classic Exam
Situs inversus totalis reverses the thoracic and abdominal organs. The heart points right, the liver sits left, the spleen and stomach sit right, and the cecum and appendix migrate to the left lower quadrant. Nothing about the appendix itself is defective or displaced in the ordinary sense. It is exactly where it belongs relative to everything else in that person's body.
Estimates of how common it is vary considerably by source. The Cureus authors cite roughly 1 in 100,000. The surgical team behind a 2025 case report places the rate at 1 in 10,000 to 25,000 live births, and a 2024 case report and review in Radiology Case Reports cites 1 per 5,000 to 10,000 live births. The wide range reflects how often the condition is never diagnosed at all, since most people with it have no symptoms and no reason to be imaged.
Left-sided appendicitis is rarer still. That same 2024 review notes situs inversus accounts for more than two-thirds of reported cases, with the rest attributed to midgut malrotation or an unusually long appendix reaching across the midline. A 2023 systematic review of the surgical and radiological literature concluded that both variants should be included in the differential diagnosis for anyone presenting with left lower quadrant pain.
There is a further wrinkle that makes the trap worse. Some patients with situs inversus still feel pain in the right lower quadrant despite the reversed anatomy, apparently because visceral nerve pathways do not mirror the organs. Left-sided pain is a clue, but right-sided pain does not rule out the diagnosis.
Age Made a Difficult Diagnosis Harder
The patient's age compounded everything. Appendicitis is the most common cause of acute abdominal pain requiring surgery, according to the National Institute of Diabetes and Digestive and Kidney Diseases. It peaks in adolescents and young adults, which is part of why it is easy to discount in a 78-year-old.
The case authors note that in patients over 65, complicated appendicitis is reported in anywhere from 18% to 70% of cases, perforation occurs in roughly 35%, and complication and mortality rates can reach about 8% compared with around 1% in younger patients. Age-related immune, vascular, and tissue changes blunt the classic presentation and reduce the accuracy of standard scoring systems. The authors also point to the man's smoking, long-term alcohol and drug use, and limited access to care as factors that likely delayed him further.
When Recognition Comes Early, Surgery Is Routine
The contrast case is instructive. Surgeons in Saudi Arabia described a 23-year-old man with left iliac fossa tenderness whose chest X-ray showed the heart on the right side. That single finding raised suspicion of situs inversus, and a CT scan confirmed it along with an inflamed appendix on the left. He had a laparoscopic appendectomy using a mirror-image three-port arrangement, went home two days later, and was symptom-free at follow-up.
The anatomy did not make the operation dangerous. The delay did.
The practical message for readers is limited but worth stating plainly. Abdominal pain that persists, worsens, or comes with fever, vomiting, or blood in the stool warrants evaluation regardless of which side it is on, and anyone who has been told they have dextrocardia or reversed organs should mention it in an emergency department without waiting to be asked.
Key Questions Answered
What is situs inversus totalis?
A congenital condition in which the chest and abdominal organs are arranged in a mirror image. The heart points right, the liver sits on the left, and the appendix sits in the left lower abdomen.
Is the appendix itself abnormal in these patients?
No. It is in its correct position relative to the rest of that person's anatomy. Only the overall body plan is reversed.
How rare is left-sided appendicitis?
Very. Published reviews describe it in case-report numbers rather than population rates, and situs inversus accounts for more than two-thirds of reported cases.
Does everyone with reversed organs feel appendicitis pain on the left?
No. Published reports describe patients with situs inversus who still experience right lower quadrant pain, which is one reason the diagnosis gets missed.
Why was this case so severe?
A 36-day delay allowed the appendix to perforate and infection to reach the liver and portal vein. Age and other risk factors also blunted the typical presentation.
When should someone with abdominal pain seek emergency care?
Pain that is severe, persistent, or worsening, especially with fever, repeated vomiting, abdominal rigidity, or blood in the stool, should be evaluated urgently regardless of location.
