Acute phlegmonous appendicitis with deciduosis: a case report and literature review.

Acute appendicitis is a common disease in pregnancy that is often difficult to diagnose. However, delayed diagnosis may have a negative impact on the pregnant woman and the fetus. In this report, we present the case of a 34-year-old pregnant woman with acute appendicitis. The appendicitis was diagnosed based on her abdominal symptoms, but it was difficult to diagnose based on preoperative imaging studies. Pathological examination led to the diagnosis of appendiceal decidua. Acute appendicitis due to appendiceal decidua is extremely rare and has only been described in a few case reports. It is difficult to diagnose appendiceal decidua from imaging findings. When a pregnant woman is diagnosed with acute abdomen, clinicians should consider appendiceal decidua as one of the causes of acute appendicitis.