Appendix sepsis tracking along the lateral cutaneous nerve of the thigh.

A patient presented with tracking of pus from a chronic appendiceal abscess along the lateral cutaneous nerve of the thigh. In the absence of such a tunnel, which is only present in a small proportion of individuals, the infection would have resulted in a subinguinal psoas abscess. Although pus may conceivably extend in any direction, the reason for this unusual complication remains poorly understood.