Pediatric Extradural Spinal Masses:Spectrum of Common and Uncommon

Pathology Affecting the Young Spine

Remy R. Lobo, MDStephen F. Kralik, MD

Isaac C. Wu, MD

eEdE#: eEdE-201Control#: 851

• No financial disclosures

Purpose/Background

• CNS tumors are second only to hematopoeitic malignancies in the pediatric population

• Spinal tumors make up less than 10% of these• This exhibit presents a spectrum of extradural

spinal masses and proposes a framework to characterize these tumors in practice

“Back” ground

• Most articles focus on the intramedullary space lesions (red)– ~60% of spinal lesions

• Or the intradural, extramedullary space lesions (blue)– ~25% of spinal lesions

Illustration A. Micheau – MDe-anatomy4, ©IMAIOS 2015

• This exhibit will focus on everything else

• Bone (purple)• Soft tissue– Nerves– Fat– Muscles

• Lesions in both spaces (bone & soft tissues) #EverythingBUTtheCORD!

Illustration A. Micheau – MDe-anatomy4, ©IMAIOS 2015

• So, with that settled• Let’s play ball!

• With a few sports analogies thrown in for effect!

Spectrum of normal

• First, we will cover the normal findings as children age– i.e. what’s fair?

Normal (continued)

• 3 month old• Note the ossification

center at C1• Hematopoietic marrow– Hypointense on T1– T2 slightly hyperintense

CT

T1 T2

Normal (continued)

• 2 year old spine:– Developing bone– T1 hypointense

(hematopoeitic)– Slightly T2

hyperintense

Normal (continued)

• 6 year old spine– Bone continues to

develop on CT– Increasing T1 signal– Some decrease in T2

(bone is still active)

• Lumbosacral spine shows similar T1 and T2 characteristics

Normal (continued)

• By 10-11 years of age, bone marrow can approximate (CT) mineralization and signal intensity (on T1 and T2) seen in adults

CT T1 T2

Normal (continued)

• Old enough to drive:– Mineralization is

basically equivalent to an adult

– T1 hyperintense and predominantly T2 hypointense fatty marrow

A structured approach:

• History often points to a diagnosis• Is the process– Bone?– Soft tissue?– Both?

• Signal characteristics

Know the rules

“Frozen” bones

• 9 year old with an obvious bone finding– Osteopetrosis Dense and sclerotic bones

• She was playing outside and fell

• Diffusely abnormal T1 and T2 bone marrow signal

Extradural T1 isointense, T2 hypointense lesion with mass effect on the cord. Note the associated cord edema

T1 isointense extradural lesion with mass effect at the cordT2 hypointense, note cord the associated edema

(descending corticospinal tract)

“Classic” case

• No enhancement on axial T1+C or sagittal T1+C with FS confirms initial suspicion

• Epidural hematoma• She had decompression surgery performed

given the acute cord edema #HistoryALWAYShelps!

Edge finding:

• A 2.5 year old with fever and abdominal pain got a CT abdomen study

Small hypoattenuating lesions in the spleen (possible abscesses?)

Notice the subtle finding at the spine?

Better demonstrated on the coronal

Fever and back pain (continued)T1 isointense and T2 hyperintense extradural lesion, Exits neural foramen into the soft tissues

Axial and coronal T1+C with FS show the peripherally enhancing extradural lesion matching the clinical picture of suspected

infection

Fever and Back Pain

• Team approach with a good history helps guide management

• Multiple bony abscesses on sagittal T1+C with FS

• Emergent laminectomy with cultures performed

• Specimen grew S. aureus

#It’salwaysStaph

Lesions outside the lines

• 16 year old girl with chronic anemia and multiple CVAs– MRA MIPs images (Rt and Lt)

• She had spine imaging because of numbness, back pain, and difficulty walking

• Low intensity extradural lesions on both T1 and T2

Moyamoya disease

• Note abnormal hypointense marrow– Hypointense tissue on T1 and T2

• No significant enhancement on T1+C with FS, axial and sagittal

• Sickle cell patient, treated with repeated pheresis exchanges

• Extramedullary hematopoeisis

#ValGlu@position6

End of the first set

• History is very helpful– Abscess favored with fever– Hematopoeisis in the setting of chronic anemia– Hematoma in cases of recent trauma/dyscrasias

• The next set will focus on bone lesions

Easy as 1, 2, 3

• 14 year old boy with back pain

• Subtle left L4 pedicle lucency

• Expansile lesion, smooth margins

• 3 phase bone scan, photopenic

• Signal mimics fluid on T1 (left) and T2 (right) MRI

Coronal T2 shows the expansion seen on radiograph

At the plate

Out of the park?

• Mild peripheral enhancement on axial, sagittal T1+C with FS

• Aneurysmal bone cyst (ABC)• Treated percutaneously

#ABC_easyas123

Often associated with fluid-fluid levels (on T2) though not seen here

One more at the wall:

• 10 year old girl with neck pain• Lucent C3 lesion on radiograph• CT shows the expansile lesion,

arising from bone• Left sided asymmetric collapse of

the vertebral body, and right sided expansion

• Isointense axial and sagittal T1, with mixed signal intensities on T2 weighted sequences

• Diffuse bony enhancement without expansile soft tissue component, possible septations?

• Magnified T2 shows the septations and a fluid fluid level

• Aneurysmal Bone Cyst

#cantALLreadtheBOOK!

Some things start small

• 14 year old girl with neck pain, often worse at night

• T2 MRI shows edema at C7

• Focal radiotracer accumulation on the left at this same level

Neck pain (cont’d)

• Centrally sclerotic nidus at the left C7 lamina

• Surrounding lucency• Osteoid osteoma• Typical history and age helps

cinch the diagnosis– Note, nidus is <1.5cm in size• Some sources cite 2 cm

CT (axial)

#TeenagePAINintheNECK

CT (sag)

Need an aspirin yet?

• 6 year old girl with scoliosis– Expansile lesion on T1, T2– Note mixed signal on axial T2

• Had taken NSAIDs before the scoliosis worsened

• Diffuse enhancement on T1+C• Osteoblastoma at excision

#GIANTosteoidosteoma

From a ‘cord’ of sorts

• 7 year old male with a history of limping for several months

• Axial T1 iso-intense and T2 hyper-intense left sacral mass

• Enhancement on sagittal T1+C• Tc MDP bone scan shows mild

radiotracer accumulation – (atypical in this case)

• CT portal and delayed phase show the soft tissue enhancement, bony destruction, and minimal calcification (note absence of fat)

• Notochord remnant, most commonly seen at the sacrum, though rare at pediatric patients

• Chordoma – Ecchordosis Physaliphora doesn’t enhance

• Can occur anywhere along the neural axis#dorsumsella2coccyx

Bony lesions summary

• Fluid-fluid levels favor ABC (1o or 2o origin)• Teenager with pain and small sclerotic focus is

likely an osteoid osteoma– Osteoblastoma when the nidus is > 1.5cm– Can dedifferentiate to osteoblastic osteosarcoma

• Chordoma commonly occurs at the sacrum, T2 hyperintense and enhancing

• Additional lesions could include Giant Cell Tumor, Chondrosarcoma and metastases

Halftime, want an orange?

• Those were bone lesions• Next will be lesions arising

in the soft tissues• Followed by lesions from

soft tissue and bone– If you get tired… Here’s

a good excuse:

Also, playing a World Cup winning German side

Hit the court

• 7 week old with stridor– Paraspinal soft tissue

• CT abdomen shows the mass isodense to muscle

• Coronal STIR shows the multilevel involvement, contiguous with multiple neural foramina on sagittal

• Isointense to muscle on T1, spanning multiple levels as seen on CT

• Diffusely hyperintense on T2, distinct from the right adrenal gland (not shown)

• Most likely a nerve sheath tumor, favor sympathetic chain origin (especially given age and location)

• Diffusely enhancing T1+C with FS• Neuroblastoma at excision– Good prognosis early, especially if

there are skin lesions (stage 4S)– Adrenal gland > sympathetic chain >

thoracic > other sites

• Can check urine catecholamines• Commonly metastasizes, can

involve any location#PEDSboardreview_flashback!

Neural tumor spectrum

• 7 year old boy who presented with cough

• Heterogeneously enhancing posterior mediastinal mass

• Spans multiple levels, neuroforaminal invasion

• As seen on MRI– T1 and T2

• Sagittal T1, T2, STIR and coronal T2 redemonstrate the multilevel paraspinal mass

• Post contrast T1 images show its extradural location and diffuse enhancement

• Findings suggest a tumor of neural origin• Ganglioneuroblastoma (GNB)– May be hard to distinguish from NB

#cantALWAYStell?!

Ringing a different “bell”

• 6 year old female with gait abnormalities and urinary incontinence receives an MRI

• Expansile hypo-intense T1 and a hyperintense T2 lesion exiting the spinal canal

• The cord is displaced laterally

coronal

• Sagittal T1 and T2 show the extradural origin• Diffuse enhancement on axial and sagittal T1+C– Note the expanded neural foramen (*)

• Again, suspect nerve tissue origin, though from a peripheral nerve in this case

• Schwannoma

*

#dumbbell_(0-0)_shape

Balancing things out

• 10 year old girl with CMTC– Cutis Marmorata

Telangiectatica Congenita• Presented with scoliosis,

hemihypertrophy, and developmental delay

• Expansile T1 isointense tissue, T2 hyperintense

• Exits neural foramina• Mass effect at nerve

• Diffusely enhancing on T1+C• DDx includes Schwannoma, and hemangioma• Look for additional clues (right rib lesion)– Isointense on T1, hyperintense on T2– Diffusely enhancing

• Hemangioma

#WHEREStheCORDUROY?

Bonus T2 image shows a syrinx, and an additional hemangioma

In the trenches

• 13 year old female with difficulty walking– Hypointense without

suppression on STIR– Left (T1) and Right (T2)

show similar findings

• Extensive component into the soft tissues, out the foramina

T1 T2 STIR

Breaking through the gaps

• Diffuse enhancement on axial and sagittal T1+C with FS

• Excision showed epidural lymphoma – Diffuse Large B-Cell Lymphoma

• Treated with chemotherapy• Common pediatric malignancies– Leukemia, lymphoma– Intracranial neoplasms

#onEVERYradiologyDDx!

Soft Tissue summary

• Often arise from neural tissue– Think neuroblastoma (evaluate adrenals)– Ganglioneuroblastoma– Schwannoma (peripheral nerve sheath tumor)

• Don’t forget about hemangioma as a mimic• Robust enhancement may favor lymphoma• What is the most common extradural soft

tissue tumor? Metastasis

#WHENinDOUBTWe’ll finish with tumors of both soft tissue and bone

“Ultimate” case?

• 6 year old boy with back pain– Flattened vertebral body• Vertebra plana

• Similar findings on MRI– Expansile soft tissue– Retropulsion– Replaces vertebra

T1 T2

T1 T2

But not a “Disc” problem

• Enhances profusely on axial and sagittal T1+C FS

• Muscle density on CT• Can obtain tissue for

diagnosis– Have needle, will stick!

• Eosinophilic granuloma– Langerhans cell histiocytosis

Prone

#EVERYpediatricDDX!

Hidden lesions

• 10 year old girl with neck pain• Unremarkable CT on bone window• Mass seen on soft tissue window– Paraspinal and extradural– Posterior extent on coronal– Similarly on sagittal

Sagittal images show a T1 isointense, T2 hypointense mass without suppression on STIR, suggestion of osseous involvement (tumor on both sides of bone).

Coronal and sagittal T1+C show the necrotic center, and diffuse peripheral enhancement. Lesion remains in the extradural space, permeating the bone.

Ewing sarcoma (ES)

• Enhancement on T1+C is typical• ES is a small round blue cell tumor– PNET, leukemia, lymphoma and other

SmRBCT all may appear similar to ES

• Second decade is most common, male predominance (2:1)

• • Complications (due to spinal location) and recurrence (due to incomplete resection)

#SmRBCT=BAD!

Bone and Soft Tissue Summary

• LCH (EG) often presents with vertebra plana• ES has an extensive soft tissue component,

but will look like other SmRBCTs• Other tumors include rhabdomyosarcoma,

aggressive hemangioma, metastasis• Infection can be a confounding feature

Conclusion

• History and demographics are crucial in evaluating pediatric epidural masses

• Discerning the tissue of origin is useful in developing an appropriate differential diagnosis

• Intrinsic signal characteristics, enhancement, and secondary findings are helpful tools for narrowing potential etiologies of pathology

• Keep differentials broad, as many patients fail to read the book!

Thank you for taking the time, please send questions or comments to: rlobo@iupui.edu

References• Micheau, A. Illustration on slides 4-5. e-anatomy4, ©IMAIOS 2015• Additional images are credited by website in the notes section of the slide in which they appear

• Duong LM et al. Descriptive epidemiology of malignant and nonmalignant primary spinal cord, spinal meninges, and cauda equina tumors, United States, 2004-2007. Cancer. 2012 Sept;118(17):4220-7.

• Khursheed N et al. Pediatric epidural tumors of the spine--experience of a decade from the Kashmir Valley. Pediatr Neurosurg. 2011;47(1):22-30.

• Menashe SJ, Iyer RS. Pediatric spinal neoplasia: a practical imaging overview of intramedullary, intradural, and osseous tumors. Curr Probl Diagn Radiol. 2013 Nov-Dec;42(6):249-65.

• Rossi A et al. Tumors of the spine in children. Neuroimaging Clin N Am. 2007 Feb;17(1):17-35.• Schick U, Marquardt G. Pediatric spinal tumors. Pediatr Neurosurg. 2001 Sep;35(3):120-7.• Shekdar KV, Schwartz ES. Imaging pediatric spine tumors. Applied Radiology. November 5, 2014.

http://www.appliedradiology.com/articles/imaging-pediatric-spine-tumors• Wilson PE, Oleszek JL, Clayton GH. Pediatric spinal cord tumors and masses. J Spinal Cord Med.

2007; 30 Suppl 1:S15-20.

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