Aberrant muscles at the Guyon’s canalthe fibers

During routine anatomical dissections two cases of unusually structured abductor digiti minimi muscle were discovered. In the first case, the variant muscle body was composed of three well-defined portions: lateral, intermediate and medial. The three portions fused in a common muscular body that attached to the ulnar side of the base of the fifth proximal phalanx. In the second case, the aberrant muscle was composed of two portions: lateral and medial. Distally, they fused in a common muscular body that distally inserted as in previous case. Because in each one of the cases a portion from the aberrant muscle crossed over the ulnar nerve and artery in the Guyon’s canal, both variant abductor digiti minimi muscles could be of clinical interest in differential diagnosis of ulnar nerve entrapment.