Infectious pseudotumor due to thorn injury.

Background: A 66-year old male patient is referred to the MR-department because of pain at the medial side of the right foot, especially during walking and standing. The patient is a gardener, and six weeks before he had stepped on a thorn of the blackthorn (Prunus Spinosa). It had pierced through the sole of his shoe, and the patient remembers finding it difficult pulling the thorn out of his foot. He then developed an inflammation of the thenar of the foot, for which antibiotic drugs were administered orally. The inflammation disappeared, but the pain remained.