14th Jun 2021

ICRI CASE OF THE WEEK

Contributed by : Dr. G. Ananta Ram, Dr. Ashwini Krishnan
KIMS Hospitals, Secunderabad

Copyright of the Case belongs to : Dr G. Ananta Ram

Clinical Details

• 63 years old female presented with neck pain and weakness of left upper limb
for 15 days, loss of weight and appetite for 6 months, lower back ache for
many years and also right lower limb pain radiating into foot for 15 days

• Physical examination revealed neck tenderness, muscle power of 4/5 in
bilateral upper limbs and lower limbs, and small muscle weakness of left
upper limb

• She was advised Magnetic Resonance Imaging of Brain and Cervical spine with
Whole spine screening





What are the findings?
What are the signs demonstrated in the post contrast sequences?
What is the provisional diagnosis?
What are the differential diagnosis to be considered?

T1 & T2 weighted Magnetic resonance imaging showing T1 isointense & T2 hypointense
intramedullary lesion at C3-C4 level, with surrounding disproportionate edema

Post gadolinium contrast T1 weighted Magnetic Post gadolinium contrast T1 weighted Magnetic
Resonance Imaging Sagittal view showing flame sign Resonance Imaging Axial view showing rim sign

Imaging Findings

• Magnetic Resonance Imaging of Cervical spine demonstrated a well defined T1 iso,
T2 hypointense intramedullary lesion measuring 5 x 10 x 21mm at C3-C4 level, with
disproportionate perilesional edema, which on post contrast study showed mild
homogenous enhancement with flame sign and rim sign- Intramedullary spinal
cord metastasis.

• Magnetic Resonance Imaging of Brain demonstrated two well defined lesions
showing thick peripheral rim enhancement.

• Magnetic Resonance maging of Whole spine demonstrated T2 hypointense lesion in
L3 vertebra with patchy enhancement.

Discussion

• Intraspinal Cord Metastasis (ISCM) is a rare complication that can occur can occur at any stage of the
primary malignancy.

• Metastasis to CNS is common, however intramedullary spinal metastasis constitutes only about 4.2-8.5%
among them. Most of the ISCM arise from lung cancer (54%) followed by breast cancer (11%), Renal cell
carcinoma (9%), Melanoma (8%) and lymphoma (4%).

• Hematogenous spread is the proposed mechanism for metastasis, and the rich blood supply to the cervical
spinal cord is expected to be responsible for increased incidence of regional involvement.

• Sudden onset and rapid progression of neurological deficits is the most common clinical manifestations of
ISCMs. Weakness is the most common symptom in patients with ISCM. Other symptoms like sensory loss,
backache, urinary incontinence and Brown Séquard syndrome are also seen. Asymptomatic patients are
also seen even in the case of multiple ISCMS.

• Plain Radiology does not have role in the diagnosis of ISCM. FDG and PET were found to be useful in
some reports, however CT is more useful in the diagnosis of extramedullary metastasis. MRI with its post
gadoliniuim contrast sequences proves to be the most efficient diagnostic modality in detecting ISCM.

• Features of ISCM in MRI are:
• Typical pattern of enhancement in post gadolinum contrast sequences.
• Extensive T2 hyperintensity in spinal cord around the lesion- showing edema.
• Rarity of hemorrhage and intra-peritumoral cystic-necrotic changes.
Typical pattern of enhancement in post gadolinum contrast sequences
• Rim sign - a complete or partial thin peripheral rim of gadolinium enhancement more intense than the

central enhancement of a non-cystic/necrotic lesion

• Flame sign - an ill-defined flame-shaped region of gadolinium enhancement at the superior
and/or inferior margin of an otherwise well-defined lesion

• Both the rim and flame signs can be present in the same lesion.
• These rim and flame signs were prevalent in ISCMs and rare in primary cord masses. Among

spinal cord masses, the rim and flame signs thus have high specificity for spinal cord metastases.
• Radiotherapy is the treatment either as supplementary postoperative or as a mainstay of

treatment for ISCM, particularly for radiosensitive carcinomas.
• Overall, intramedullary spinal cord metastasis carries worse prognosis with a mortality rate of

80% during the first three to four months after the manifestation of the first symptom.

Differential Diagnosis

The closest differential diagnosis for an ISCM is intramedullary hemangioblastoma

• Significant perilesional edema is seen in both ISCM and hemangioblastomas
• Hemangioblastomas usually show a typically bright enhancing mass, clearly delineated

from the surrounding spinal cord tissue on post contrast sequences, whereas ISCM shows
typical flame sign and rim sign
• MR images of large hemangioblastomas may also show flow voids resulting from
prominent vessels

Teaching Points

Intramedullary spinal cord metastasis with typical MRI findings, without any known primary malignancy
demonstrated in this case.

Typical MR findings demonstrated in this case:
• Rim sign - a complete or partial thin peripheral rim of gadolinium enhancement more intense than the

central enhancement of the lesion
• Flame sign - an ill-defined flame-shaped region of gadolinium enhancement at the superior and/or inferior

margin of the lesion
• Typical T2 hyperintensity showing disproportionate edema around the lesion.
• Absence of peritumoral cysts and hemorrhage.

Hemangioblastoma is the closest differential diagnosis.
Differentiating features seen in hemangioblastoma are
• bright enhancement with clear delineation
• flow voids
• Absence of rim and flame sign.

References

1. Kalayci M, Çağavi F, Gül S, Yenidünya S, AçikgözB.Intramedullary spinal cord metastases: diagnosis and
treatment - an illustrated review. ActaNeurochir (Wien). 2004 Dec;146(12):1347-54; discussion 1354.
PMID:15526223.

2.Potti A, Abdel-Raheem M, Levitt R, Schell DA, Mehdi SA. Intramedullary spinal cord metastases (ISCM) and
non-small cell lung carcinoma (NSCLC): clinical patterns, diagnosis and therapeutic considerations. Lung
Cancer 2001;31:319–23.

3.Taniura S, Tatebayashi K, Watanabe K, Watanabe T.Intramedullary spinal cord metastasis from gastric cancer.
J Neurosurg. 2000 Jul;93(1 Suppl):145-7.PMID: 10879773

4. Rykken JB et al. Rim and flame signs: post gadolinium MRI findings specific for non-CNS intramedullary
spinal cord metastases. AJNR. 2013 Apr;34(4):908-15. PMID: 23079405