Suspected Congenital Absence of the Vermiform Appendix in a 13-Year-Old Girl: A Case Report.

A congenital absence of the vermiform appendix (appendiceal agenesis) is a rare anatomical anomaly that is mostly recognised incidentally upon exploratory surgery due to suspected appendicitis. Preoperative diagnosis is difficult since symptoms and imaging studies typically resemble other causes of right lower quadrant pain. In this report, we describe an adolescent girl aged 13 who presented with right lower quadrant abdominal pain; this led to a workup to rule out acute appendicitis. Imaging studies were performed to evaluate the cause of her pain. An ultrasound examination of the abdomen demonstrated an enlarged left ovary (bulky), and a contrast-enhanced computed tomography (CT) scan of the abdomen/pelvis confirmed that there was a left ovarian cyst (3-4 cm in diameter) along with a partially calcified lesion involving the left adnexa and that the ileocaecal region appeared to be normal. Conservative treatment was not completely effective in eliminating the symptoms. Thus, surgical exploration was decided. During the operation, a small amount of reactive liquid was found in the ileocaecal area. A comprehensive and careful search of the ileocecum, followed by tracing of the taenia coli, did not reveal the presence of a vermiform appendix, and only a small 1 cm nodular structure was found at the end of the taenia coli. Congenital hypoplasia of the appendix was strongly suspected based on intraoperative findings, and hence, abdominal closure was performed without further complications. The postoperative course was uneventful. The case demonstrates how difficult it can be to diagnose appendicitis when clinical findings and imaging studies present ambiguity in diagnosis.