Aspergillus terreus spondylodiscitis following an abdominal stab wound: a case report

Abstract

Background: Aspergillus terreus, a saprophytic fungus, is recognized as an emerging pathogen in various infections in humans. However, bone and joint involvement is uncommon. To the best of our knowledge, only seven cases of spondylodiscitis caused by Aspergillus terreus have been reported previously in humans. We report a case of a patient with Aspergillus terreus spondylodiscitis following an abdominal stab wound.

Case presentation: A 74-year-old Japanese man with no particular medical history fell from a ladder and sustained a left abdominal stab wound from an L-shaped metal peg. Computed tomography showed the trace of the L-shaped metal peg from the left abdomen to the left rib and left kidney. The scan also showed an anterolateral bone avulsion of the left side of the T12 vertebral body, as well as fractures of the L1 left transverse process and the left 10th-12th ribs. He was hospitalized and treated with conservative therapy for 6 weeks. He was readmitted to the hospital with complaints of sudden back pain, numbness of both legs, and inability to walk 13 weeks after the fall. Magnetic resonance imaging findings were typical of spondylodiscitis. Gadolinium-enhanced T1-weighted magnetic resonance imaging indicated increased signal intensity at T11-T12 vertebral bodies and severe cord compression and epidural abscess at T11-T12 associated with infiltration of soft paravertebral tissues. On the seventh day after admission, he underwent partial laminectomy at T11 and posterior fusion at T9 to L2. The result of his blood culture was negative, but Aspergillus terreus was isolated from the material of T11-T12 intervertebral disc and vertebral bodies. His Aspergillus antigen was positive in a blood examination. Histological examination showed chronic suppurative osteomyelitis. On the 35th day after admission, he underwent anterior fusion at T11 and T12 with a rib bone graft. For 5 months, voriconazole was administered, and he wore a rigid corset. Posterior partial laminectomy at T11 and anterior fusion at T11 and T12 resulted in a good clinical course. The patient's neurological dysfunction was completely recovered, and his back pain disappeared. Two years after the operation, computed tomography was performed and showed bone fusion at T11 and T12. Magnetic resonance imaging revealed no evidence of increased signal intensity at T11-T12 vertebral bodies and severe cord compression and epidural abscess at T11-T12.

Conclusions: To our knowledge, this is the first report of spondylodiscitis caused by Aspergillus terreus after an abdominal penetrating injury. The histological finding of chronic suppurative osteomyelitis and the radiological findings strongly suggested direct inoculation of Aspergillus terreus.

Keywords: Antifungals; Aspergillus terreus; Fungal infection; Open fracture of thoracic vertebra; Spondylodiscitis; Vertebral osteomyelitis.

Fig. 1

Reconstruction computed tomography showed the fracture of T12 vertebral body. The fracture line passed from the left inferior edge of T12 vertebral body towards the central upper edge of T12 vertebral body (left, middle: fracture line: white arrows). Axial views of computed tomography scan showed the fracture of T12 vertebral body and an abdominal stab wound at L3 level (right upper: anterolateral bone avulsion of the left side of the T12 vertebral body: white arrow, right under: an abdominal stab wound: white arrow)

Fig. 2

X-ray image showing narrowing of T11–T12 intervertebral disc space at 6 weeks and 10 weeks. A computed tomographic scan at 13 weeks showed numerous irregular osteolytic cavities in T11 and T12 vertebral bodies and destruction of the inferior endplate of T11 and the superior endplate of T12

Fig. 3

Gadolinium-enhanced T1-weighted magnetic resonance imaging indicated increased signal intensity at T11–T12 vertebral bodies and severe cord compression and epidural abscess at T11–T12 associated with infiltration of soft paravertebral tissues

Fig. 4

Operative specimen from the T12 vertebra. Left: Inflammatory granulation between trabecular bone (H&E stain, original magnification × 100). Right: Numerous neutrophils seen in the granulation (H&E stain, original magnification × 400). Histological examination showed chronic suppurative osteomyelitis

Fig. 5

Postoperative computed tomography demonstrated anterior fusion at T11 and T12 with rib bone graft

Fig. 6

Two years after the operation, computed tomography demonstrated bone fusion at T11 and T12

Fig. 7

Magnetic resonance imaging revealed no evidence of increased signal intensity at T11–T12 vertebral bodies and severe cord compression and epidural abscess at T11–T12