A 30-year-old female patient presents with a large lesion on her left foot. Her complaints started 5 years ago as pain and itching on the plantar aspect of the foot which slowly progressed into an indurated swelling with multiple sinuses. She does not give any history of trauma to the foot. She works as a manual labourer. On examination, the left foot is enlarged with a tumour-like lesion that has numerous discharging sinuses. An X-ray of the foot showed lucencies in the metatarsal bones. There was no regional lymphadenopathy.
The patient was afebrile and haematological and biochemistry investigations were normal. The sinus discharge was seropurulent with yellowish white grains present. These grains on microscopy showed gram-positive branching filamentous structures. Acid fast staining was negative. What is the diagnosis? Source: Rattanavong, Sayaphet et al. BMC Infectious Diseases 12…
