Table 1.

Previous cases of paraneoplastic tumefactive demyelination accompanied by seminoma.

Case	Age (years)	Sex	Symptoms	Imaging findings	Biopsy	Antibodies	Treatment	Response	Author
1	41	M	Depression, difficulty with concentration and memory.	Decreased T1-low and T2-high signals in the occipital lobes and corpus callosum, with some peripheral contrast enhancement.	Macrophage infiltration, reactive astrocytosis, demyelination, and preserved axons.	Negative for anti-Hu, –Yo, and –Ri antibodies.	Oral corticosteroid therapy and radiation to the seminoma.	Good response.	Jaster JH
2	54	M	Confusion and memory loss.	T1-low and T2-high signals on the corpus callosum and parieto-occipital white matter. Minimal mass effect and no contrast enhancement.	Foamy macrophages and reactive astrocytes. Complete myelin loss and moderate axonal loss.	Not assessed.	Chemotherapy and dexamethasone.	Partial response. Memory deficit remained.	Wong K
3	37	M	Left facial numbness and left-sided ataxia.	T1-low and FLAIR-high lesion in the left middle cerebellar peduncle. Irregular ring enhancement was present.	Not performed.	Elevation of anti-nuclear, –cardiolipin, and –double-stranded DNA antibodies. Negative for anti-Hu, –Ri, –Yo, and –Ma2 antibodies.	Dexamethasone and radiation therapy to the seminoma.	Good response. 4 years later, he became asymptomatic.	Plotkin SR
4	60	M	Memory loss and homonymous right upper quadrantanopia.	Large confluent lesion affecting both occipitoparietal lobes, crossing the splenium of the corpus callosum.	No evidence of neoplasia. Demyelination, CD68-positive macrophage infiltration containing myelin debris, and scattered CD45+ and CD3+ lymphocytes.	Negative for anti Yo, –Hu, and –Ri antibodies.	Cisplatin and etoposide for seminoma. Initial steroid pulse was ineffective. Repeated steroid pulse and five plasma exchanges were added.	Partial response. Left hemianopia and memory impairment remained.	Broadfoot JR
5	62	M	Headache, right-sided weakness, and receptive aphasia.	T1-low and T2-high lesion in the left frontoparietal area with a small mass effect and gadolinium enhancement. MRS showed an NAA/choline ratio of 0.42 with a lactate peak.	No evidence of neoplasia. Demyelination and infiltration of CD68-positive foamy macrophages.	Negative for anti-Ma2, –AQP4, and –MOG antibodies.	Steroid pulse, oral steroids, and radiotherapy to the seminoma.	Poor response. Severe right hemiparesis remained.	Thebault S
6	47	M	Motor aphasia and right facial and brachial paresis.	T1-low and T2/FLAIR-high lesion that expanded through the internal capsule to the left cerebral peduncle, imcomplete ring enhancement, and visualized central veins. Mass effect was small.	No evidence of neoplasia. CD68-positive macrophage infiltration and perivascular lymphocytic infiltration.	Negative for anti–Hu, –Yo, –Ri, –CV2, –Ma1, –Ma2, –Ta, –amphiphysine, –Zic, –SOX, –GAD65, –Tr, –ANNA3, –PCA2, and –cerebellum antibodies.	Sterod pulse, oral corticosteroid, and radical orchiectomy.	Partial response. Aphasia and paresis recovered. Behavioral problems remained.	Van Haver AS
Present case	32	M	Right hemiplegia and right hemianopia.	T1-low and T2/FLAIR-high lesion in the left thalamus. Enhancement was absent. Choline, NAA, and lactate peaks on MRS.	No evidence of neoplasia. Demyelination, CD68-positive macrophage infiltration with myelin debris, and axonal damage.	Positive for anti-amphiphysin antibodies. Negative for anti-nuclear, –AQP4, and –MOG antibodies.	Radical orchiectomy, bleomycin, etoposide, and cisplatin for seminoma. Steroid pulse and gamma globulin therapy for demyelination.	Partial response. Hemiparesis and hemianopsia remained.	Shiraishi W

ANNA, anti-neuronal nuclear antibody; AQP4, aquaporin-4; CD, cluster of differentiation; FLAIR, fluid-attenuated inversion recovery; GAD, glutamate decarboxylase; M, male; MOG, myelin oligodendrocyte glycoprotein; MRS, magnetic resonance spectroscopy; NAA, N-acetyl aspartate; PCA, Purkinje cell antibody.