MRI findings of leptomeningeal metastases in a patient with breast cancer

Clinical History

The patient, coming from the Oncology unit, suffered from breast cancer surgically treated a year before. At admission she showed mental confusion associated to cephalea, convulsions and vertigo.

Imaging Findings

MR examination on 1.5 T system, coil dedicated, on the axial, coronal and sagittal plans, using SE T1W, FSE T2W sequences, with signal fluid suppression (FLAIR) and integrated with administration of paramagnetic contrast agent, were performed.
Diffuse on the subarachnoid level spaces of the cerebral convexity and, in particular, pericerebellar a tenuous hyperintensity in the sequence with signal fluid suppression were visualised; enhancement clearly showing after administration of the paramagnetic contrast medium. Linear areas of enhancement at level of the pons and others, of nodular type, at cervical level were visualised.

Discussion

Leptomeningeal carcinomatosis (LC) refers to diffuse seeding of the leptomeninges by tumour metastases. LC can be secondary, beyond that to haematic spread from extra-cranial tumours, also to intracranial neoplasms that are spread through cerebrospinal fluid. Among the extra-cranial tumours the greater leptomeningeal involvement is present in the leukaemias, while only in 5% of the mammary carcinomas and in 3% of the melanomas. The incidence of the leptomeningeal metastases is in increase both due to a longer survival of those with neoplastic disease, and for greater sensibility of MRI in evidencing this patology [1]. In the primitive neoplasms of the nervous system, the means of leptomeningeal dissemination occurs through the cerebrospinal fluid. Instead, the neoplasms extra-nervous or extra-cranial system cause leptomeningeal metastases, in the greater part of the cases, through haematic way. The first localisation is represented by the small arachnoid vessels and of the choroid plexus; from these vessels, the neoplastic cells secondarily spread to the adjacent leptomeninx. The sub-arachnoid/arachnoid dissemination are characterised by infiltrated spread or extensively multifocal, with leptomeningeal thickening, while focal nodular metastases are rare. The common onset is the paralysis of various cranial nerves and spinal roots, often of difficult differentiation regarding the para-neoplastic syndromes. Symptoms of leptomeningeal metastases may include: headache, mental confusion, loss of control of the bladder or bowel, vision and hearing problems. A direct MRI examination, the most frequent proof is that of an obliteration or filling of the sub-arachnoid spaces, of diffused or localised type. The metastatic localisation may appear like nodular foci, micro- or macro-nodular or linear along the surface of the encephalic nervous structures. They generally appear isointense or slightly hyperintense in the T1-weighted sequences, they become hyperintense in the T2-weighted sequences and, in this case, they are confused with hyper-intense signal of cerebrospinal fluid; they are therefore better distinguishable if sequences with suppression of signal fluid (FLAIR) are used. After administration of contrast agent, the leptomeningeal metastases are constantly impregnated and are easier to recognise in the hypointensity of the liquor, even if of small dimensions [2]. There is no agreed-upon standard treatment for leptomeningeal metastases. Much of the time, the benefits of treatment are offset by treatment side effects. Treating symptoms of the disease but not the disease itself may be the best option. This may include radiation and chemotherapy intravenous and intrathecal. Despite enhanced diagnosis with MRI, prognosis remains poor in leptomeningeal metastases.

Differential Diagnosis List

Final Diagnosis

Multiple and diffuse leptomeningeal metastases from breast cancer

URL:	https://www.eurorad.org/case/10868
DOI:	10.1594/EURORAD/CASE.10868
ISSN:	1563-4086