An Acute Abdomen Mimicking Appendicitis

A 58-year-old-man presented to the emergency unit with abdominal pain and fever for three days. He had no history of nausea or vomiting. The abdominal examination revealed a minimally distended abdomen with tenderness in the right lower quadrant (RLQ). At palpation, there was no rebound tenderness or defence. Laboratory findings revealed inflammation and a high white blood cell count, predominantly neutrophils. Contrast enhanced CT examination of the abdomen shows a 12cm, oval-shaped, low-attenuation cystic lesion (21 HU) with mural curvilinear calcifications (Figure 1, AM), contiguous with the distal appendix in the RLQ (Figure 2, A). A breach (Figure 1, arrow) is observed in the anterior aspect of the wall as well as an adjacent small fluid-like collection (Figure 1, asterisk) with no significant difference in density between this feature and the principal mass (19 HU). Moderate periappendiceal fat stranding is also seen (Figure 1, arrowhead). Based on these findings the diagnosis of a probably ruptured appendiceal mucocele (AM) was made. Surgery revealed the presence of greyish white gelatinous material into the peritoneal cavity confirming the diagnosis of rupture of a mucocele. Open laparotomy was chosen in order to minimize trauma and avoid further spilling of mucus. The gelatinous material was removed and the mucocele of the appendix was resected.