Abstract

Background:Vertebral osteomyelitis caused by Stenotrophomonas maltophilia is very rare. There are only two cases reported in literature. Here, we present a 48-year-old immunocompetent male who, following a lumbar microdiscectomy, developed postoperative spondylodiscitis due to S. maltophilia that mimicked a cotton granuloma.

Case Report:Two months ago, a 48-year-old male underwent a lumbar L4-L5 microdiscectomy, he newly presented with the left thigh and leg pain of 4 weeks duration. Laboratory studies revealed a CRP of 26 mg/l, an ESR of 6 mm (1^st h), and total leukocyte count of 7.85 thousand/ul. The MRI T2 images showed a focal hyperintense lesion in the left lateral recesses at the L4-L5 level; the accompanying hypointense-smooth margin resembled a cotton granuloma. At surgery, we found a localized epidural collection of pus; S. maltophilia was isolated from the culture. His symptoms gradually improved, and symptoms fully resolved with 3 months of subsequent antibiotic therapy.

Conclusion:S. maltophilia causing vertebral osteomyelitis is extremely rare and can sometimes mimic a cotton granuloma. MR diagnosis, surgical decompression, and obtaining cultures are requisite to direct appropriate antibiotic therapy.

Keywords: Cotton granuloma, Spondylodiscitis, Stenotrophomonas maltophilia

INTRODUCTION

Different spinal infections include spondylodiscitis, septic discitis, spondylitis, and/or vertebral osteomyelitis (e.g., including endplate and/or epidural abscess). However, vertebral osteomyelitis caused by S. maltophilia attributed to a lumbar microdiscectomy is very rare.[ 2 , 3 ] Here, we present a 48-year-old immunocompetent male who, following a lumbar microdiscectomy, developed the unusual postoperative complication of spondylodiscitis due to S. maltophilia that resembled a cotton granuloma.

CASE REPORT

Two months ago, a nonimmunocompromised hypertensive 48-year-old male underwent an L4-L5 microdiscectomy [ Figures 1 and 2 ]. He newly presented with 4 weeks of increasingly severe left thigh and leg pain. His only neurological finding was SLR positive on the left side at 30°.

Figure 1:

Preoperative T2W image showing left L4–L5 paracentral disc prolapse.

Figure 2:

Preoperative T1W image showing left L4–L5 paracentral disc prolapse.

Laboratory studies showed a CRP of 26 mg/l, an ESR of 6 mm (1^st h), and total leukocyte count of 7.85 thousand/ul. MRI T2 images showed a focal hyperintense lesion in the left lateral recesses at the L4-L5 level with an accompanying hypointense/smooth margin resembling a cotton granuloma [ Figures 3 and 4 ].[ 6 ] The differential diagnoses included a cotton granuloma versus an epidural abscess. At surgery, a collection of epidural pus was found at the L4-L5 level; the culture grew S. maltophilia [ Figure 5 ]. The patient was placed on 6 weeks of intravenous cefoperazone-sulbactam followed by 6 weeks of oral levofloxacin. After this treatment, his infection fully resolved, and he exhibited no residual neurological sequelae.

Figure 3:

Postoperative T2W image showing focal hyperintense lesion in the left lateral recess with a hypointense and smooth margin resembling a cotton granuloma.

Figure 4:

Postoperative T1W image showing focal hypointense lesion in the left lateral recess causing significant central canal compression.

Figure 5:

Intraoperative image showing pus collection in the lateral recess.

DISCUSSION

S. maltophilia is a Gram-negative aerobic bacillus that is commonly found in the environment causing hospital- acquired infections in immunocompromised hosts. It is typically resistant to most broad-spectrum antibiotics.[ 2 , 3 ] These lesions may mimic a cotton granuloma which is defined as a foreign body reaction to cotton sponges and/or cotton fibers accidentally left in the body during spine surgery.[ 6 ]

Laboratory studies

Laboratory evaluations for S. maltophilia infections typically show elevated WBC counts (60%), elevated ESR and CRP levels (90%), and positive blood cultures (65%).[ 5 ] Gadolinium-enhanced MRI studies best differentiate infection from degenerative and/or tumor; they are both sensitive (96%) and specific (94%) for documenting S. maltophilia lesions. Open surgery (for debridement, decompression, and fusion) or CT-guided FNAC for a core biopsy (e.g., typically 70% successful in diagnosing this pathogen) should be performed to culture this organism and guide appropriate antibiotic therapy.[ 1 , 4 ]

CONCLUSION

A high degree of suspicion was required in this case to diagnose S. maltophilia as causing postoperative spondylodiscitis and must be differentiated from cotton granulomas. Here, after obtaining definitive cultures utilizing open surgical approach, prolonged antibiotics treatment was warranted.

Declaration of patient consent

Patient’s consent not required as patient’s identity is not disclosed or compromised.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1. Chen WH, Jiang LS, Dai LY. Surgical treatment of pyogenic vertebral osteomyelitis with spinal instrumentation. Eur Spine J. 2007. 16: 1307-16

2. Denton M, Kerr KG. Microbiological and clinical aspects of infection associated with Stenotrophomonas maltophilia. Clin Microbiol Rev. 1998. 11: 57-80

3. Friedman ND, Korman TM, Fairley CK, Franklin JC, Spelman DW. Bacteraemia due to Stenotrophomonas maltophilia An analysis of 45 episodes. J Infect. 2002. 45: 47-53

4. Gasbarrini A, Boriani L, Salvadori C, Mobarec S, Kreshak J, Nanni C. Biopsy for suspected spondylodiscitis. Eur Rev Med Pharmacol Sci. 2012. 16: 26-34

5. Kang BU, Lee SH, Ahn Y, Choi WC, Choi YG. Surgical site infection in spinal surgery: Detection and management based on serial C-reactive protein measurements. J Neurosurg Spine. 2010. 13: 158-64

6. Okten AI, Adam M, Gezercan Y. Textiloma: A case of foreign body mimicking a spinal mass. Eur Spine J. 2006. 15: 626-9