A case of cystic lymphatic malformation mimicking acute appendicitis in an adult patient: a rare diagnostic pitfall.

Abdominal cystic lymphatic malformations are rare pathological entities of uncertain aetiology that usually present in early childhood with indolent abdominal distention. We report the case of a 17-year-old man who presented to our hospital with acute right lower quadrant pain, nausea and anorexia. His blood tests revealed a raised white cell count and elevated inflammatory markers. Clinical examination revealed signs of localised right lower quadrant peritonism. A diagnosis of clinical appendicitis was made, and in keeping with local management protocols, the patient proceeded to theatre for a diagnostic laparoscopy without radiological investigations. Operative findings yielded a normal appendix and a large abdominal cystic malformation. This article highlights the need to keep a broad differential diagnosis when performing surgery on patients with clinically presumed appendicitis and the importance of radiological investigations in clinical decision-making, we also review abdominal cystic lymphatic malformations as a rare diagnostic pitfall.