The "dot in circle" sign on MRI in maduramycosis: a characteristic finding.

Mycetoma or Maduramycosis is a localized chronic suppurative infection characterized by exuberant granulation tissue, discharging sinuses, and bone involvement later in the course of the disease. Early clinical diagnosis before the appearance of sinuses and grains (aggregates of organism surrounded by granulation tissue, which are discharged from the draining sinuses) is difficult. Delay in diagnosis may lead to amputation of the affected part. Definitive diagnosis is through biopsy and microbiological examination. However, at times diagnosis may still be difficult. The recently described "dot in circle" sign on magnetic resonance imaging (MRI) is easy to recognize and highly specific. We present a case of mycetoma foot with characteristic MRI features.