Ultrasonographic imaging of mycetoma

Abstract

Introduction: The ultrasonographic appearance of mycetoma is described in this prospective study.

Methods: One hundred patients with foot swellings had sonographic evaluation of the swelling and surgical excision within 2 weeks of ultrasonography. The histopathological findings were compared with the preoperative images. Some of the excised swellings and grains were also imaged and compared with the in vivo findings.

Results: The mycetoma grains, their capsules and the accompanying inflammatory granulomas have characteristic ultrasonographic appearances. In eumycetoma lesions, the grains produce numerous, sharp hyper-reflective echoes and there are single or multiple thick-walled cavities with no acoustic enhancement. In actinomycetoma, the findings are similar but the hyper-reflective echoes are fine, closely aggregated and commonly settle at the bottom of the cavities. None of the non-mycetoma foot swellings (which included lipoma, ganglion, foreign body granuloma and others) studied had these features.

Conclusion: Ultrasonography is simple, non-invasive, quick, reproducible and acceptable to patients. Mycetoma has characteristic ultrasonographic features. Furthermore, ultrasonography delineates the extent of mycetoma more accurately than clinical examination alone.