Hemorrhagic ganglion of the tibialis anterior tendon: report of an unusual variant.

While clinicians have encountered heme-laden ganglion cysts in the past, to our knowledge the condition has never been described in the literature as a distinct pathological entity, namely, the hemorrhagic ganglion. Because hemorrhage may alter the appearance of an aspirate obtained from a ganglion cyst, and hemosiderin deposition within a ganglion cyst may alter the signal characteristics observed on a magnetic resonance image, such that both of these diagnostic methods may suggest the presence of a solid mass tumor rather than a ganglion cyst, it is important for clinicians and surgeons to be aware of the possibility of the presence of a hemorrhagic ganglion cyst. In this report, we present a case wherein a hemorrhagic ganglion cyst of the tibialis anterior tendon was identified and excised.