Paraneoplastic tumefactive demyelination

Case contributed by Dr Aanand Vibhakar


A 30 year old gentleman presented with a 7 day history of expressive dysphasia.

Patient Data

Age: 30
Gender: Male

Axial non-contrast CT Head

Solitary intracerebral lesion in the inferior left frontal lobe with associated mass effect, edema and subtle hyperdense rim.


MRI Brain

T2 hyperintense mass centered in the white matter of the left frontal lobe. There is associated peripheral diffusion restriction and a small focus of peripheral enhancement (demonstrated on the post-contrast images)


Ultrasound Testes

7mm hypoechoic region in the left testis


CT Abdomen

32mm left para-aortic lymph node

The working diagnosis initially included a primary brain tumour and lymphoma.

The abdominal CT demonstrated a 32mm para-aortic lymph node. Testicular ultrasonography revealed a 7mm hypoechoic region in the left testicle. 

Stereotactic biopsy of the para-aortic lymph node revealed a histological diagnosis of metastatic seminoma. 

The axial T2 images demonstrated a hyperintense white matter lesion in the left frontal lobe. Diffusion imaging revealed a peripheral rim of diffusion restriction consistent with a possible diagnosis of active demyelination. T1 post-gadolinium images showed a small focus of enhancement at the periphery of the lesion. 

The patient had curative chemotherapy for his metastatic seminoma. He subsequently had a resection of his left frontal lobe lesion.

Histology from the resected lesion confirmed demyelination and reactive changes with no evidence of neoplasia.

The patient subsequently underwent a left inguinal orchidectomy. The histology revealed a scar typical of a regressed tumour.

Case Discussion

This case demonstrates tumefactive demyelination as a paraneoplastic disorder. It is a rare, locally aggressive form of demyelination 1. In patients without a diagnosis of multiple sclerosis it can pose a diagnostic quandry; and can often mimic a neoplasm. Peripheral diffusion restriction, a predeliction for the periventricular and deep white matter, minimal mass effect and decreased perfusion leans the diagnosis towards tumefactive demyelination rather than malignancy 2.

Paraneoplastic neurological disorders are remote mainfestations of malignancy unrelated to metastases or the tumor itself. The greatest chance of neurological recovery comes from treating the associated malignancy and hence early diagnosis plays a vital role 3


Case contributed by Dr David Swienton and Dr Aanand Vibhakar

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Case information

rID: 58678
Published: 28th Feb 2018
Last edited: 16th Jul 2018
Inclusion in quiz mode: Included

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