Actinomycetoma of the hand: a case report

Abstract

A 68-year-old, otherwise well Somalian man was referred to our plastic surgery service with a 5-year history of a slow-growing painless subcutaneous mass over the right palmar region (Fig. 1). This was previously excised in an overseas institute and recurred over the period of a few months. Ultrasound showed a welldefined moderately vascular soft tissue lesion with increased Doppler flow, separate to the flexor tendons, measuring 3.7 × 2.4 × 3.4 cm in size. Magnetic resonance imaging (MRI) showed a non-specific subcutaneous soft tissue mass with high signal on T2 fat saturation with multiple low signal ‘grains’ (Figs 2,3). There was no bony involvement. Differentials included a giant cell tumour or a vascular malformation. An excisional biopsy showed an actinomycetoma: multiple inflammatory nodules were seen with features characteristic of Splendore Hoeppli phenomenon – microorganisms surrounded by eosinophilic material. Gram stain showed filamentous, gram-positive bacteria, consistent with actinomyces. The patient was referred to the infectious diseases department for consideration of further antibiotic treatment prior to consideration of surgical intervention. Mycetoma, colloquially known as ‘Madura foot’, is a chronic subcutaneous infection typically following traumatic inoculation of bacteria (actinomycetoma) or fungi (eumycetoma) into skin. Classically, it presents as a discharging subcutaneous mass but can involve bone or viscera. It is endemic in tropical regions including Africa, but rare in developed countries. Ultrasound and fine-needle aspirate are diagnostic although MRI assists in grading the lesion. On MRI, the lesion has high signal on T2 fat saturation images containing grains visible as spherical hyperintense lesions with central