[Myelopathy secondary to thoracic actinomycetoma]

Mycetoma is a chronic subcutaneous infection caused by fungi (eumycetoma) or filamentous bacteria (actinomycetoma), acquired through traumatic inoculation. It affects the skin, subcutaneous tissue, and in advanced cases, deeper structures such as bones or the spinal cord. Its presentation can lead to severe complications, including paraplegia.

74-year-old male farmer hospitalized due to sudden-onset paraplegia, with inability to walk and urinary and fecal incontinence. A dermatology consult was requested for a dermatosis affecting the trunk, located on the posterior aspect of the left hemithorax, which was localized and asymmetrical. The lesion consisted of multiple fistulas discharging purulent secretion and numerous erythematous-violaceous atrophic scars that coalesced to form a plaque measuring 30 x 30 cm. Neurologically, a complete spinal cord syndrome was diagnosed. Microbiological studies revealed the presence of grains measuring between 50 and 100 μm composed of filamentous bacteria, positive for periodic acid-Schiff (PAS) stain and acid-fast with Ziehl-Neelsen staining, consistent with Nocardia spp. Magnetic resonance imaging showed involvement of vertebrae T6, T7, and T8.

Actinomycetoma is endemic in Mexico. The classic triad includes a subcutaneous mass, fistulas, and grains. Its progression can cause vertebral destruction and myelopathy. Magnetic resonance imaging is the diagnostic study of choice due to its high soft tissue resolution. Therapeutic management combines antibiotics with activity against actinomycetes.