- Email: [email protected]
Spinal Intradural Escherichia coli Abscess Masquerading as a Neoplasm in a Pediatric Patient with History of Neonatal E. coli Meningitis: A Case Report and Literature Review
Case Report
Spinal Intradural Escherichia coli Abscess Masquerading as a Neoplasm in a Pediatric Patient with History of Neonatal E. coli Meningitis: A Case Report and Literature Review Miri Kim1, Joshua Simon1, Kamran Mirza2, Kevin Swong1, Stephen Johans1, Loren Riedy1, Douglas Anderson1
Key words Escherichia coli - Intradural spinal abscess - Meningitis - Spinal cord tumor -
Abbreviations and Acronyms MRI: Magnetic resonance imaging From the Departments of 1Neurological Surgery and 2 Pathology, Loyola University Medical Center, Maywood, Illinois, USA To whom correspondence should be addressed: Douglas Anderson, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2019) 126:619-623. https://doi.org/10.1016/j.wneu.2019.02.243 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com
- BACKGROUND:
Central nervous system abscesses frequently can be seen in the immunocompromised population and most commonly consist of intracranial collections in the adult patient. Spinal intradural abscesses are less commonly encountered, and there are even fewer numbers in the pediatric population with a concordant absence of documentation in the published literature.
- CASE
DESCRIPTION: In this case report, we describe the presentation of a 2year-old boy with a history of perinatal Escherichia coli meningitis at 2.5 months of age who was found to have an intradural spinal lesion, initially concerning for neoplasm, but later confirmed as an E. coli abscess following biopsy. He was managed with surgical aspiration of the abscess and a long course of intravenous antibiotics. The patient was treated with antibiotics with repeat imaging studies that revealed residual abscess that required re-aspiration at a later date.
- CONCLUSIONS:
Here we present an unusual disease process with an unusual disease pathogenesis in a pediatric patient currently residing in a developed country.
1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
INTRODUCTION Spinal intradural mass lesions are an uncommon entity but are thoroughly documented in the neurosurgical literature, with almost all pathologic diagnoses returning as neoplastic in nature. Although an infectious etiology remains on the differential diagnosis, especially in the predisposed patient, there is a paucity of literature and study in the pediatric population. Here we present a case report of a 2-year-old boy who presented with bilateral lower-extremity weakness and imaging findings initially concerning for syringomyelia in the setting of an intrinsic primary spinal cord neoplasm. Magnetic resonance imaging (MRI) of the brain was obtained and was found to be grossly normal. Surgical intervention with biopsy and expansion duraplasty demonstrated a spinal intradural abscess with positive culture for pan-sensitive Escherichia coli. CASE PRESENTATION A 2-year-old male patient with a medical history of E. coli meningitis at the age of 2.5 months with mild motor development
delay presented to the emergency department with irritability, leukocytosis, refusal to walk, and the finding of a corneal abrasion. The patient was treated with nonsteroidal anti-inflammatory drugs and eye drops and sent home without imaging studies with gross resolution of symptoms. He re-presented to the emergency department 5 months later with a 1- to 2-week regression in ability to ambulate. At presentation, the patient was febrile with a temperature of 101 F, a leukocytosis of 14.5, and erythrocyte sedimentation rate of 54. The patient could crawl without issue; however, could not walk, was increasingly irritable and experienced weight loss, from the 25th to 5th percentile despite otherwise-normal progression in development. Physical examination revealed an awake and alert, extremely irritable and anxious-appearing child. His bilateral lower extremities were noted to be flexed at the knees at rest with decreased tone and muscle bulk throughout. He was able to extend his knees against gravity but had decreased dorsiflexion and absent deep tendon reflexes with exquisite pain with passive extension of his lower extremities with
WORLD NEUROSURGERY 126: 619-623, JUNE 2019
guarding bilaterally without tenderness to palpation of the back. Patient was initially evaluated for musculoskeletal factors and assessed by orthopedic surgery for hip pathologies which were unrevealing. Imaging Findings and Intraoperative Observations MRI of the brain and the entire spine with and without contrast revealed dilatation of the central canal of the spinal cord beginning at the level of the second thoracic vertebra (T2) growing more prominent caudally, with a heterogeneous, multicystic, intramedullary mass versus cyst obscuring the conus medullaris and cauda equina with heterogeneous enhancement on T1 MRI sequence extending from lumbar three to sacral one (L3 S1) (Figure 1). These findings were initially concerning for syringomyelia in the setting of an intrinsic spinal tumor. A steroid regimen was initiated before surgery with mild improvement in lower-extremity mobility and tolerance to weight bearing. The patient underwent T12 L5 laminectomies, tissue biopsy, and expansion duraplasty. The patient was found to have extremely adherent dura to
www.journals.elsevier.com/world-neurosurgery
619
CASE REPORT MIRI KIM ET AL.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
Figure 1. Pre- and postoperative magnetic resonance imaging (MRI). (A) T2-weighted image demonstrating cord dilation at the level of T2, becoming increasingly prominent distally with a heterogeneous intramedullary mass obscuring the conus medullaris and cauda equina. (B) Preoperative MRI studies redemonstrating heterogeneous signal intensity with dilation of
the ligamentum flavum with significant scarring of the conus to several exiting nerve roots with noted hypervascularity. High-density proteinaceous cerebrospinal fluid and purulence was expressed from the cystic lesion at L1 (Figure 1B) and sent for pathology and cultures. Initial frozen section diagnosis reported high mitotic figures, concerning for malignancy and necrosis. Pathology Biopsy of the intramedullary lumbar lesion showed spinal cord parenchyma with a robust inflammatory infiltrate in a background of reactive gliosis (Figure 2A). The infiltrate was accentuated around prominent blood vessels and was composed of lymphocytes, plasma cells, histiocytes, and neutrophils. Phenotypic evaluation was performed with a battery of immunohistochemical stains. These stains showed the infiltrate was a mixture of CD20-positive B cells and CD3-positive T cells (Figure 2B, C). There were equal numbers of CD3- and CD5-positive T cells. Staining for glial
620
www.SCIENCEDIRECT.com
the spinal cord and 2 fluid-filled cystic lesions at L1 and L3eL4. (C) T1 postcontrast imaging with demonstration of lobular heterogeneous enhancement and the cystic dilated regions. (D) Postoperative changes status post laminectomies and drainage of rostral cystic lesion with resolution of the L1 cystic lesion.
fibrillary acidic protein highlighted intermediate filaments of occasional astrocytes. Neurofilament stained scattered intact neurons and luxol blue/PAS highlighted myelin. Analysis of Epstein Barr virus with in situ hybridization for Epstein Barr virus encoded RNA was negative. Staining for CD10 was negative in the lymphocytes. Assessment of kappa and lambda immunoglobulin by in situ hybridization showed a polytypic pattern of light chain expression. Although the inflammatory infiltrate was dense and accentuated around vessels, there were no histologic findings that supported a diagnosis of neoplasia. It was noted to be conceivable that the infiltrate was secondary to a separate primary process. Postoperative Course Cultures from the operating room yielded pan-sensitive E. coli prompting the initiation of antibiotic treatment. Patient began ceftriaxone therapy with transition to ampicillin to complete a 3-week course. Postoperative MRI revealed decreased size
and enhancement of the intradural fluid collection with decreased dural enhancement surrounding the distal conus region and cauda equina. Postoperative physical examination revealed a well-appearing child in no acute distress, smiling and interactive, moving all extremities symmetrically and spontaneously at rest. He demonstrated avoidance to weight-bearing of the bilateral lower extremities with limited dorsiflexion of the right lower extremity when compliant with physical exam. Patient continued to improve and was subsequently discharged to an inpatient rehabilitation facility. A repeat surveillance MRI was obtained 1-month postintervention, which demonstrated improvement in the thoracic spine; however, imaging showed persistent enhancement of the more inferior cystic lesion within the lumbar spine (Figure 1C). Patient subsequently underwent repeat open aspiration and fenestration of the lumbar abscess without difficulty. With ultrasound guidance, the dura was opened between the previous exposure at L3 L5 with expanded laminectomy to
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2019.02.243
CASE REPORT MIRI KIM ET AL.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
Figure 2. Pathologic assessment of intraoperative specimen. (A) Hematoxylin and eosin stained sections demonstrate spinal cord parenchyma with a dense inflammatory infiltrate that is accentuated around prominent blood vessels (arrows). The infiltrate is composed of lymphocytes, histiocytes, plasma cells, and neutrophils. Reactive gliosis is noted in the background. Immunohistochemical characterization of the lymphocytes shows a mixture of some CD20-positive B cells (B) and CD3-positive T cells (C).
visualize normal dura (Figure 3A). Intracapsular material was white and proteinacious and sent for repeat cultures (Figure 3B, C). Due to significant scarring and adherence to surrounding neural elements, abscess capsule remained behind. Dura was closed primarily (Figure 3D). Intraoperative cultures returned without positive growth demonstrating successful treatment of the abscess. The patient continued to demonstrate improvement in his neurologic examination, pulling to standing, bending his knees without issue, and was discharged
home postoperatively with continued outpatient physical therapy. At 6-month follow-up, the patient had completed his course of physical therapy. He was ambulating and even running well without noticeable deficits, no longer requiring his brace, and meeting milestones appropriately. DISCUSSION One study estimated an incidence of spinal epidural abscesses as 1.5 per 10,000 admissions over a 9-year period1; however, fewer intradural and less than 100
WORLD NEUROSURGERY 126: 619-623, JUNE 2019
intramedullary abscesses have been noted in the literature.2 Pediatric spinal intradural abscesses are less commonly encountered, with a concordant absence of documentation in the published literature. These infections have a male predominance and most typically affect patients in the first and third decades of life when affecting the pediatric patient.3 Intradural spine abscesses in the adult literature often demonstrated a prolonged and indolent course of vague symptoms. More than 50% of patients presented with fever and almost 85% with nerve root associated pain with 37% presenting with a combination of both, with 82% of adults progressing to develop motor deficits.4 Lesions more commonly occur as solitary abscesses and are not frequently seen in the thoracic spine.5 This case highlights an unusual presentation of an intradural abscess mimicking an intradural malignancy in a patient with a past medical history of meningitis. In developing countries, with the onset of antimicrobial resistance, the most common bacterial pathogens associated with meningitis within the first 90 days of life are group B strep followed by E. coli. Late onset (from day 7e29) was more commonly E. coli, whereas extremely lateonset meningitis (day 30e90) was most often Group B streptococci, E. coli, Neisseria meningitides, and Haemophilus influenza type B.6 Mycobacterium tuberculosis has also been described as the causative organism in certain cases.1,7 Viral etiologies for spinal infections also include herpes virus, polio viruses, and cytomegalovirus A. Spinal epidural abscesses in pediatric populations are more commonly seen in children with immune deficiencies or sickle cell anemia, with the primary organism being Staphylococcus aureus. Known trauma or presence of an epidural hematoma is a predisposing factor in many cases of epidural abscesses. Subdural extramedullary infections are significantly less documented, with a greater prevalence in the thoracic spine. Often times, these patients had spinal dysraphism or a dermal sinus tract.6 Intramedullary spinal infections has a median age of presentation of 3 years, often associated with dermoid or epidermoid lesions and are also more prevalent
www.journals.elsevier.com/world-neurosurgery
621
CASE REPORT MIRI KIM ET AL.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
intensity on diffusion-weighted imaging with low apparent diffusion coefficient values, which were initially studied in intracranial abscesses.11
Figure 3. Intraoperative imaging findings. (A) Dura was opened between previous exposure at L3eL5, expanded laminectomy, via a midline incision and retracted with stay sutures. Arachnoid matter remained intact. (B) Capsule was identified and opened with purulent appearing material (solid arrow). (C) After drainage of purulent material, adherent capsule (dashed arrow) remained. (D) Dura was closed primarily. *Represents previous duraplasty.
in the thoracic spine.8 Infection and hematogenous spread of urinary tract infection, pneumonia, and middle ear infections also have been associated with intramedullary infection. The largest source of hematogenous spread generally originated from the urogenital tract.9 Dermal sinus tracts have been associated with 53% of intramedullary infections; however, our patient did not present with any sinus tract.1 The average age of patients who present with intramedullary infections in the presence of a dermal sinus tract was 22.6 months. These patients presented with fever and lowerextremity weakness, often growing back S. aureus and requiring surgical intervention with good outcomes.10 In addition, trauma and pyogenic meningitis are closely associated. Diagnosis of these spinal infections often is difficult, as patients present in a multitude of ways ranging from fecal incontinence, weakness, with or without fever. The median duration of signs or symptoms ranged from 1 day to 3 years after trauma. Only 56% of patients presented with fever, whereas 42% of patients presented with paralysis.9
622
www.SCIENCEDIRECT.com
Our patient presented with intermittent fevers and fussiness for several months before developing deficits on physical examination, prompting further imaging studies. Interestingly, he had meningitis at the age of 2.5 months with documentation of E. coli meningitis diagnosed by lumbar puncture and cerebral spinal fluid cultures. At that time, he underwent a course of intravenous antibiotics as appropriate. Radiographic Findings Radiographic findings of these intramedullary lesions often demonstrate peripheral rim enhancement in its late stages, with associated findings of surrounding edema and cord expansion that may oftentimes resemble diffuse infiltrating neoplasm or demyelinating diseases. Other entities, including resolving hematomas and infarcts, can present as ring-enhancing lesions. Thus, recent use of diffusion-weighted imaging has been a critical tool for differentiating potential diagnoses. The necrotic contents of an abscess and its high protein content as well as cellular debris restrict water molecules resulting in increased signal
Treatment Modalities Despite the rarity of intramedullary intradural abscesses in the pediatric population, treatment follows historical case reports of surgical biopsy, fenestration, and appropriate antibiotic therapies.9 Antimicrobial therapies with median duration of 20 days resulted in mortality of 10% compared with preantibiotic era studies’ case fatality rate of 71%. Aggressive and early surgical intervention before the onset of neurologic deficits was important; however, diagnosis often is delayed due to the indolent and variable presentation, especially in children who are unable to communicate and have not yet been toilet trained. The most common levels of involvement were in the thoracolumbar spine, with predisposing factors of a midline defect. Those without anatomic abnormalities more commonly had cervical involvement.12 Abscess cultures available in some studies demonstrated that 55% of patients have a single organism isolate, 17% with mixed flora, and 25% with sterile fluid, with almost one half of the cases reporting previous antibiotic use.9
CONCLUSIONS In this patient, apparent incomplete treatment of previous meningitis may have contributed to the formation of an indolent abscess within the subdural and intramedullary space rather than epidural space. Here, the patient presented to the emergency department on 2 occasions with fever of unknown origin, leukocytosis, and refusal to walk. Imaging studies were concerning for neoplastic process, yet given his history of meningitis, infection could not be ruled out. This patient benefited from surgical intervention as well as a prolonged course of antibiotics with repeat evacuation of cystic lesions. With the resources available to aggressively rehabilitate the patient, resulted in significant improvement to near-normal lower-extremity function and overall neurologic status.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2019.02.243
CASE REPORT MIRI KIM ET AL.
REFERENCES 1. Tyagi R. Spinal infections in children: a review. J Orthop. 2016;13:254-258. 2. Velissaris D, Aretha D, Fligou F, Filos KS. Spinal subdural Staphylococcus aureus abscess: case report and review of the literature. World J Emerg Surg. 2009;4:31. 3. Menezes AH, Graf CJ, Perret GE. Spinal cord abscess: a review. Surg Neurol. 1977;8:461-467. 4. Bartels RH, de Jong TR, Grotenhuis JA. Spinal subdural abscess. Case report. J Neurosurg. 1992; 76:307-311. 5. Aggarwal M, Aggarwal KC, Karamchand, Aggarwal A. Intramedullary spinal cord abscess masquerading as spinal tumor. Indian Pediatr. 2011; 48:973-974. 6. Mohanty CB, Fieggen G, Deopujari CE. Pediatric spinal infections—a review of non-tuberculous infections. Childs Nerv Syst. 2018;34:1947-1956.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
7. Murphy KJ, Brunberg JA, Quint DJ, Kazanjian PH. Spinal cord infection: myelitis and abscess formation. AJNR Am J Neuroradiol. 1998;19:341-348. 8. Candon E, Frerebeau P. Bacterial abscesses of the spinal cord. Review of the literature (73 cases). Rev Neurol (Paris). 1994;150:370-376 [in French]. 9. Simon JK, Lazareff JA, Diament MJ, Kennedy WA. Intramedullary abscess of the spinal cord in children: a case report and review of the literature. Pediatr Infect Dis J. 2003;22:186-192. 10. Prasad GL, Hegde A, Divya S. Spinal intramedullary abscess secondary to dermal sinus in children [e-pub ahead of print]. Eur J Pediatr Surg. 2018. https://doi.org/10.1055/s-0038-1655736. Accessed November 2, 2018. 11. Cartes-Zumelzu FW, Stavrou I, Castillo M, Eisenhuber E, Knosp E, Thurnher MM. Diffusionweighted imaging in the assessment of brain abscesses therapy. AJNR Am J Neuroradiol. 2004;25: 1310-1317.
WORLD NEUROSURGERY 126: 619-623, JUNE 2019
12. Kurita N, Sakurai Y, Taniguchi M, Terao T, Takahashi H, Mannen T. Intramedullary spinal cord abscess treated with antibiotic therapy—case report and review. Neurol Med Chir (Tokyo). 2009; 49:262-268.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 6 February 2019; accepted 27 February 2019 Citation: World Neurosurg. (2019) 126:619-623. https://doi.org/10.1016/j.wneu.2019.02.243 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
www.journals.elsevier.com/world-neurosurgery
623
Spinal Intradural Escherichia coli Abscess Masquerading as a Neoplasm in a Pediatric Patient with History of Neonatal E. coli Meningitis: A Case Report and Literature Review Miri Kim1, Joshua Simon1, Kamran Mirza2, Kevin Swong1, Stephen Johans1, Loren Riedy1, Douglas Anderson1
Key words Escherichia coli - Intradural spinal abscess - Meningitis - Spinal cord tumor -
Abbreviations and Acronyms MRI: Magnetic resonance imaging From the Departments of 1Neurological Surgery and 2 Pathology, Loyola University Medical Center, Maywood, Illinois, USA To whom correspondence should be addressed: Douglas Anderson, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2019) 126:619-623. https://doi.org/10.1016/j.wneu.2019.02.243 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com
- BACKGROUND:
Central nervous system abscesses frequently can be seen in the immunocompromised population and most commonly consist of intracranial collections in the adult patient. Spinal intradural abscesses are less commonly encountered, and there are even fewer numbers in the pediatric population with a concordant absence of documentation in the published literature.
- CASE
DESCRIPTION: In this case report, we describe the presentation of a 2year-old boy with a history of perinatal Escherichia coli meningitis at 2.5 months of age who was found to have an intradural spinal lesion, initially concerning for neoplasm, but later confirmed as an E. coli abscess following biopsy. He was managed with surgical aspiration of the abscess and a long course of intravenous antibiotics. The patient was treated with antibiotics with repeat imaging studies that revealed residual abscess that required re-aspiration at a later date.
- CONCLUSIONS:
Here we present an unusual disease process with an unusual disease pathogenesis in a pediatric patient currently residing in a developed country.
1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
INTRODUCTION Spinal intradural mass lesions are an uncommon entity but are thoroughly documented in the neurosurgical literature, with almost all pathologic diagnoses returning as neoplastic in nature. Although an infectious etiology remains on the differential diagnosis, especially in the predisposed patient, there is a paucity of literature and study in the pediatric population. Here we present a case report of a 2-year-old boy who presented with bilateral lower-extremity weakness and imaging findings initially concerning for syringomyelia in the setting of an intrinsic primary spinal cord neoplasm. Magnetic resonance imaging (MRI) of the brain was obtained and was found to be grossly normal. Surgical intervention with biopsy and expansion duraplasty demonstrated a spinal intradural abscess with positive culture for pan-sensitive Escherichia coli. CASE PRESENTATION A 2-year-old male patient with a medical history of E. coli meningitis at the age of 2.5 months with mild motor development
delay presented to the emergency department with irritability, leukocytosis, refusal to walk, and the finding of a corneal abrasion. The patient was treated with nonsteroidal anti-inflammatory drugs and eye drops and sent home without imaging studies with gross resolution of symptoms. He re-presented to the emergency department 5 months later with a 1- to 2-week regression in ability to ambulate. At presentation, the patient was febrile with a temperature of 101 F, a leukocytosis of 14.5, and erythrocyte sedimentation rate of 54. The patient could crawl without issue; however, could not walk, was increasingly irritable and experienced weight loss, from the 25th to 5th percentile despite otherwise-normal progression in development. Physical examination revealed an awake and alert, extremely irritable and anxious-appearing child. His bilateral lower extremities were noted to be flexed at the knees at rest with decreased tone and muscle bulk throughout. He was able to extend his knees against gravity but had decreased dorsiflexion and absent deep tendon reflexes with exquisite pain with passive extension of his lower extremities with
WORLD NEUROSURGERY 126: 619-623, JUNE 2019
guarding bilaterally without tenderness to palpation of the back. Patient was initially evaluated for musculoskeletal factors and assessed by orthopedic surgery for hip pathologies which were unrevealing. Imaging Findings and Intraoperative Observations MRI of the brain and the entire spine with and without contrast revealed dilatation of the central canal of the spinal cord beginning at the level of the second thoracic vertebra (T2) growing more prominent caudally, with a heterogeneous, multicystic, intramedullary mass versus cyst obscuring the conus medullaris and cauda equina with heterogeneous enhancement on T1 MRI sequence extending from lumbar three to sacral one (L3 S1) (Figure 1). These findings were initially concerning for syringomyelia in the setting of an intrinsic spinal tumor. A steroid regimen was initiated before surgery with mild improvement in lower-extremity mobility and tolerance to weight bearing. The patient underwent T12 L5 laminectomies, tissue biopsy, and expansion duraplasty. The patient was found to have extremely adherent dura to
www.journals.elsevier.com/world-neurosurgery
619
CASE REPORT MIRI KIM ET AL.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
Figure 1. Pre- and postoperative magnetic resonance imaging (MRI). (A) T2-weighted image demonstrating cord dilation at the level of T2, becoming increasingly prominent distally with a heterogeneous intramedullary mass obscuring the conus medullaris and cauda equina. (B) Preoperative MRI studies redemonstrating heterogeneous signal intensity with dilation of
the ligamentum flavum with significant scarring of the conus to several exiting nerve roots with noted hypervascularity. High-density proteinaceous cerebrospinal fluid and purulence was expressed from the cystic lesion at L1 (Figure 1B) and sent for pathology and cultures. Initial frozen section diagnosis reported high mitotic figures, concerning for malignancy and necrosis. Pathology Biopsy of the intramedullary lumbar lesion showed spinal cord parenchyma with a robust inflammatory infiltrate in a background of reactive gliosis (Figure 2A). The infiltrate was accentuated around prominent blood vessels and was composed of lymphocytes, plasma cells, histiocytes, and neutrophils. Phenotypic evaluation was performed with a battery of immunohistochemical stains. These stains showed the infiltrate was a mixture of CD20-positive B cells and CD3-positive T cells (Figure 2B, C). There were equal numbers of CD3- and CD5-positive T cells. Staining for glial
620
www.SCIENCEDIRECT.com
the spinal cord and 2 fluid-filled cystic lesions at L1 and L3eL4. (C) T1 postcontrast imaging with demonstration of lobular heterogeneous enhancement and the cystic dilated regions. (D) Postoperative changes status post laminectomies and drainage of rostral cystic lesion with resolution of the L1 cystic lesion.
fibrillary acidic protein highlighted intermediate filaments of occasional astrocytes. Neurofilament stained scattered intact neurons and luxol blue/PAS highlighted myelin. Analysis of Epstein Barr virus with in situ hybridization for Epstein Barr virus encoded RNA was negative. Staining for CD10 was negative in the lymphocytes. Assessment of kappa and lambda immunoglobulin by in situ hybridization showed a polytypic pattern of light chain expression. Although the inflammatory infiltrate was dense and accentuated around vessels, there were no histologic findings that supported a diagnosis of neoplasia. It was noted to be conceivable that the infiltrate was secondary to a separate primary process. Postoperative Course Cultures from the operating room yielded pan-sensitive E. coli prompting the initiation of antibiotic treatment. Patient began ceftriaxone therapy with transition to ampicillin to complete a 3-week course. Postoperative MRI revealed decreased size
and enhancement of the intradural fluid collection with decreased dural enhancement surrounding the distal conus region and cauda equina. Postoperative physical examination revealed a well-appearing child in no acute distress, smiling and interactive, moving all extremities symmetrically and spontaneously at rest. He demonstrated avoidance to weight-bearing of the bilateral lower extremities with limited dorsiflexion of the right lower extremity when compliant with physical exam. Patient continued to improve and was subsequently discharged to an inpatient rehabilitation facility. A repeat surveillance MRI was obtained 1-month postintervention, which demonstrated improvement in the thoracic spine; however, imaging showed persistent enhancement of the more inferior cystic lesion within the lumbar spine (Figure 1C). Patient subsequently underwent repeat open aspiration and fenestration of the lumbar abscess without difficulty. With ultrasound guidance, the dura was opened between the previous exposure at L3 L5 with expanded laminectomy to
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2019.02.243
CASE REPORT MIRI KIM ET AL.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
Figure 2. Pathologic assessment of intraoperative specimen. (A) Hematoxylin and eosin stained sections demonstrate spinal cord parenchyma with a dense inflammatory infiltrate that is accentuated around prominent blood vessels (arrows). The infiltrate is composed of lymphocytes, histiocytes, plasma cells, and neutrophils. Reactive gliosis is noted in the background. Immunohistochemical characterization of the lymphocytes shows a mixture of some CD20-positive B cells (B) and CD3-positive T cells (C).
visualize normal dura (Figure 3A). Intracapsular material was white and proteinacious and sent for repeat cultures (Figure 3B, C). Due to significant scarring and adherence to surrounding neural elements, abscess capsule remained behind. Dura was closed primarily (Figure 3D). Intraoperative cultures returned without positive growth demonstrating successful treatment of the abscess. The patient continued to demonstrate improvement in his neurologic examination, pulling to standing, bending his knees without issue, and was discharged
home postoperatively with continued outpatient physical therapy. At 6-month follow-up, the patient had completed his course of physical therapy. He was ambulating and even running well without noticeable deficits, no longer requiring his brace, and meeting milestones appropriately. DISCUSSION One study estimated an incidence of spinal epidural abscesses as 1.5 per 10,000 admissions over a 9-year period1; however, fewer intradural and less than 100
WORLD NEUROSURGERY 126: 619-623, JUNE 2019
intramedullary abscesses have been noted in the literature.2 Pediatric spinal intradural abscesses are less commonly encountered, with a concordant absence of documentation in the published literature. These infections have a male predominance and most typically affect patients in the first and third decades of life when affecting the pediatric patient.3 Intradural spine abscesses in the adult literature often demonstrated a prolonged and indolent course of vague symptoms. More than 50% of patients presented with fever and almost 85% with nerve root associated pain with 37% presenting with a combination of both, with 82% of adults progressing to develop motor deficits.4 Lesions more commonly occur as solitary abscesses and are not frequently seen in the thoracic spine.5 This case highlights an unusual presentation of an intradural abscess mimicking an intradural malignancy in a patient with a past medical history of meningitis. In developing countries, with the onset of antimicrobial resistance, the most common bacterial pathogens associated with meningitis within the first 90 days of life are group B strep followed by E. coli. Late onset (from day 7e29) was more commonly E. coli, whereas extremely lateonset meningitis (day 30e90) was most often Group B streptococci, E. coli, Neisseria meningitides, and Haemophilus influenza type B.6 Mycobacterium tuberculosis has also been described as the causative organism in certain cases.1,7 Viral etiologies for spinal infections also include herpes virus, polio viruses, and cytomegalovirus A. Spinal epidural abscesses in pediatric populations are more commonly seen in children with immune deficiencies or sickle cell anemia, with the primary organism being Staphylococcus aureus. Known trauma or presence of an epidural hematoma is a predisposing factor in many cases of epidural abscesses. Subdural extramedullary infections are significantly less documented, with a greater prevalence in the thoracic spine. Often times, these patients had spinal dysraphism or a dermal sinus tract.6 Intramedullary spinal infections has a median age of presentation of 3 years, often associated with dermoid or epidermoid lesions and are also more prevalent
www.journals.elsevier.com/world-neurosurgery
621
CASE REPORT MIRI KIM ET AL.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
intensity on diffusion-weighted imaging with low apparent diffusion coefficient values, which were initially studied in intracranial abscesses.11
Figure 3. Intraoperative imaging findings. (A) Dura was opened between previous exposure at L3eL5, expanded laminectomy, via a midline incision and retracted with stay sutures. Arachnoid matter remained intact. (B) Capsule was identified and opened with purulent appearing material (solid arrow). (C) After drainage of purulent material, adherent capsule (dashed arrow) remained. (D) Dura was closed primarily. *Represents previous duraplasty.
in the thoracic spine.8 Infection and hematogenous spread of urinary tract infection, pneumonia, and middle ear infections also have been associated with intramedullary infection. The largest source of hematogenous spread generally originated from the urogenital tract.9 Dermal sinus tracts have been associated with 53% of intramedullary infections; however, our patient did not present with any sinus tract.1 The average age of patients who present with intramedullary infections in the presence of a dermal sinus tract was 22.6 months. These patients presented with fever and lowerextremity weakness, often growing back S. aureus and requiring surgical intervention with good outcomes.10 In addition, trauma and pyogenic meningitis are closely associated. Diagnosis of these spinal infections often is difficult, as patients present in a multitude of ways ranging from fecal incontinence, weakness, with or without fever. The median duration of signs or symptoms ranged from 1 day to 3 years after trauma. Only 56% of patients presented with fever, whereas 42% of patients presented with paralysis.9
622
www.SCIENCEDIRECT.com
Our patient presented with intermittent fevers and fussiness for several months before developing deficits on physical examination, prompting further imaging studies. Interestingly, he had meningitis at the age of 2.5 months with documentation of E. coli meningitis diagnosed by lumbar puncture and cerebral spinal fluid cultures. At that time, he underwent a course of intravenous antibiotics as appropriate. Radiographic Findings Radiographic findings of these intramedullary lesions often demonstrate peripheral rim enhancement in its late stages, with associated findings of surrounding edema and cord expansion that may oftentimes resemble diffuse infiltrating neoplasm or demyelinating diseases. Other entities, including resolving hematomas and infarcts, can present as ring-enhancing lesions. Thus, recent use of diffusion-weighted imaging has been a critical tool for differentiating potential diagnoses. The necrotic contents of an abscess and its high protein content as well as cellular debris restrict water molecules resulting in increased signal
Treatment Modalities Despite the rarity of intramedullary intradural abscesses in the pediatric population, treatment follows historical case reports of surgical biopsy, fenestration, and appropriate antibiotic therapies.9 Antimicrobial therapies with median duration of 20 days resulted in mortality of 10% compared with preantibiotic era studies’ case fatality rate of 71%. Aggressive and early surgical intervention before the onset of neurologic deficits was important; however, diagnosis often is delayed due to the indolent and variable presentation, especially in children who are unable to communicate and have not yet been toilet trained. The most common levels of involvement were in the thoracolumbar spine, with predisposing factors of a midline defect. Those without anatomic abnormalities more commonly had cervical involvement.12 Abscess cultures available in some studies demonstrated that 55% of patients have a single organism isolate, 17% with mixed flora, and 25% with sterile fluid, with almost one half of the cases reporting previous antibiotic use.9
CONCLUSIONS In this patient, apparent incomplete treatment of previous meningitis may have contributed to the formation of an indolent abscess within the subdural and intramedullary space rather than epidural space. Here, the patient presented to the emergency department on 2 occasions with fever of unknown origin, leukocytosis, and refusal to walk. Imaging studies were concerning for neoplastic process, yet given his history of meningitis, infection could not be ruled out. This patient benefited from surgical intervention as well as a prolonged course of antibiotics with repeat evacuation of cystic lesions. With the resources available to aggressively rehabilitate the patient, resulted in significant improvement to near-normal lower-extremity function and overall neurologic status.
WORLD NEUROSURGERY, https://doi.org/10.1016/j.wneu.2019.02.243
CASE REPORT MIRI KIM ET AL.
REFERENCES 1. Tyagi R. Spinal infections in children: a review. J Orthop. 2016;13:254-258. 2. Velissaris D, Aretha D, Fligou F, Filos KS. Spinal subdural Staphylococcus aureus abscess: case report and review of the literature. World J Emerg Surg. 2009;4:31. 3. Menezes AH, Graf CJ, Perret GE. Spinal cord abscess: a review. Surg Neurol. 1977;8:461-467. 4. Bartels RH, de Jong TR, Grotenhuis JA. Spinal subdural abscess. Case report. J Neurosurg. 1992; 76:307-311. 5. Aggarwal M, Aggarwal KC, Karamchand, Aggarwal A. Intramedullary spinal cord abscess masquerading as spinal tumor. Indian Pediatr. 2011; 48:973-974. 6. Mohanty CB, Fieggen G, Deopujari CE. Pediatric spinal infections—a review of non-tuberculous infections. Childs Nerv Syst. 2018;34:1947-1956.
SPINAL ABSCESS MASQUERADING AS A NEOPLASM
7. Murphy KJ, Brunberg JA, Quint DJ, Kazanjian PH. Spinal cord infection: myelitis and abscess formation. AJNR Am J Neuroradiol. 1998;19:341-348. 8. Candon E, Frerebeau P. Bacterial abscesses of the spinal cord. Review of the literature (73 cases). Rev Neurol (Paris). 1994;150:370-376 [in French]. 9. Simon JK, Lazareff JA, Diament MJ, Kennedy WA. Intramedullary abscess of the spinal cord in children: a case report and review of the literature. Pediatr Infect Dis J. 2003;22:186-192. 10. Prasad GL, Hegde A, Divya S. Spinal intramedullary abscess secondary to dermal sinus in children [e-pub ahead of print]. Eur J Pediatr Surg. 2018. https://doi.org/10.1055/s-0038-1655736. Accessed November 2, 2018. 11. Cartes-Zumelzu FW, Stavrou I, Castillo M, Eisenhuber E, Knosp E, Thurnher MM. Diffusionweighted imaging in the assessment of brain abscesses therapy. AJNR Am J Neuroradiol. 2004;25: 1310-1317.
WORLD NEUROSURGERY 126: 619-623, JUNE 2019
12. Kurita N, Sakurai Y, Taniguchi M, Terao T, Takahashi H, Mannen T. Intramedullary spinal cord abscess treated with antibiotic therapy—case report and review. Neurol Med Chir (Tokyo). 2009; 49:262-268.
Conflict of interest statement: The authors declare that the article content was composed in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. Received 6 February 2019; accepted 27 February 2019 Citation: World Neurosurg. (2019) 126:619-623. https://doi.org/10.1016/j.wneu.2019.02.243 Journal homepage: www.journals.elsevier.com/worldneurosurgery Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2019 Elsevier Inc. All rights reserved.
www.journals.elsevier.com/world-neurosurgery
623