The working diagnosis initially included a primary brain tumour and lymphoma.
The abdominal CT demonstrated a 32 mm para-aortic lymph node. Testicular ultrasonography revealed a 7 mm 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.