Congenital absence of the cecal appendix. Case report.

BACKGROUND Agenesis of the vermiform appendix is very rare and was first described by Morgagni in 1718. The estimated incidence is 1/100,000 laparotomies performed for suspected appendicitis. This case is reported with the aim of attracting the attention of surgeons who may be in a similar situation during laparotomy. CLINICAL CASE A 48-year-old male was admitted through the emergency room with the complaint of vague abdominal pain most marked in the epigastrium and mesogastrium which, 4 h after it began, was located in the right iliac fossa and was accompanied by hyporexia, nausea, vomiting and fever. During physical examination, the patient was febrile, tachycardic, and tachypneic, with decreased peristalsis, abdomen painful to palpation and percussion in the right iliac fossa. There were positive appendicular signs. Blood panel showed leukocytosis (14,000), neutrophilia (89.60%) and lymphopenia (5.33%). X-rays of the abdomen showed no abnormalities. We made a presumptive diagnosis of acute appendicitis and the patient underwent celioscopy where surgical findings were reported as type IV Collins appendiceal agenesis and concomitant mesenteric adenitis. CONCLUSIONS Several criteria must be determined before the surgeon can conclude that the appendix is congenitally absent. Diagnosis should not be confirmed until the ileo- and retrocecal regions have been explored.