ISCM in a case of breast cancer

Clinical History

A female patient, 60 years old, known to have metastatic breast cancer of the brain. The last MR revealed resolution of brain metastases.The patient then developed rapidly progressive bilateral lower limb weakness and incontinence to urine and stools. The patient was accordingly scheduled for MR examination of the spine.

Imaging Findings

A well circumscribed intra medullary lesion is noted at the thoracic spinal cord opposite D12 vertebra (at the epiconus). It displays hypointense signal on T1 and T2 weighted images. Associated long segment of hyperintense T2 signal of the spinal cord is seen extending from the level of D6 down to the conus medullaris. On post contrast series, the lesion shows intense and homogenous enhancement. The lesion does not show any cystic components or signal of blood degradation product.
MR images obtained after radiotherapy and corticosteroid therapy revealed a decrease in the size of the intra medullary mass and resolution of the associated cord oedema signal.

Discussion

Background: Intra medullary spinal cord mass lesions are masses arising from or within the spinal cord. These masses essentially expand the spinal cord. Intra medullary spinal cord neoplasms are generally considered uncommon CNS neoplasms, mostly of primary glial origin (e.g. Ependymoma, Astrocytoma) and are more commonly seen in children and young adults. Intra medullary spinal cord metastases (ISCM) are exceedingly rare and are less common than lepto meningeal metastases. The routes of spread may be: via arterial supply (hematogenous spread), directly from meninges, retrograde via venous plexus or perineural lymphatic spread [1].

Clinical perspective: ISCM present in elderly, most commonly having primary lung or breast cancer. These patients present by a notable rapid decline in their neurologic status that is typically in the form of motor weakness. The median time of presenting symptoms is 2 weeks [2]. The presentation and diagnosis of ISCM may precede that of the primary tumour. It is reported in some cases with ISCM to be asymptomatic [3].

Imaging perspective: ISCM are usually solitary expansile lesions that commonly arise in the thoracic segment followed by the cervical segment and the conus medullaris. They are commonly associated with metastases elsewhere in the CNS. The most consistent imaging features in reported cases are: (a) associated extensive peri lesional cord oedema, disproportionate size of ISCM (b) solid intense enhancement (c) lack of cystic changes or haemorrhage. These features, in the appropriate clinical setting, help to distinguish ISCM from the more common primary glial tumors, especially the lack of cysts and hemorrhage [2, 4].
It is not uncommon to visualize multiple ISCM lesions, especially in cases with CNS metastases other than within the cord [2].

Outcome:The patient presented with new neurologic insult. MRI of the spine revealed a solitary intra medullary, expansile, intensely and homogenously enhancing solid lesion within the thoracic spinal cord. The clinical presentation and the typical imaging features represent a relapse in the form of ISCM. The patient received radiotherapy and corticosteroids. Follow up MRI revealed a decrease in the size and enhancement of the ISCM lesion and resolution of the associated cord oedema.

Take home message:ISCM is a rare presentation that should be considered in the appropriate clinical setting. Typical MR imaging features include: (a) associated extensive peri lesional oedema, disproportionate size of ISCM (b) solid intense enhancement (c) lack of cystic changes or haemorrhage.

Differential Diagnosis List

Final Diagnosis

Intra medullary Spinal Cord metastases from breast cancer

URL:	https://www.eurorad.org/case/12973
DOI:	10.1594/EURORAD/CASE.12973
ISSN:	1563-4086