Presentation
Headache
Patient Data
A large hemorrhagic mass is seen in the frontal lobe on the right with enhancement and surrounding vasogenic edema.
There is a large solitary mass at the grey-white matter junction of the right frontal lobe which demonstrates heterogeneous T1 and T2 signal with a large amount of intrinsic T1 hyperintensity particularly inferiorly and posteriorly. There is a large amount of hemosiderin staining. The lesion demonstrates irregular enhancement. It is surrounded by white matter T2/FLAIR hyperintensity surrounding the mass which spares the cortex. This extends into the genu of corpus callosum.
The mass demonstrates elevated CBV. MRS is non-contributory.
Conclusion:
Large hemorrhagic right frontal mass is favored to represent a metastasis, for example melanoma.
Case Discussion
This patient had a past history melanoma (three years earlier) making this the likely diagnosis. He went on to have surgery.
Histology
MICROSCOPIC DESCRIPTION: Paraffin sections show a densely hypercellular tumor. Tumor cells have markedly pleomorphic round and oval vesicular nuclei with conspicuous nucleoli and a variable amount of pale cytoplasm. These are arranged in diffuse sheets within a vascular stroma. Frequent mitotic and apoptotic figures are identified and there is extensive tumor necrosis. Tumor cells show strong immunostaining for tyrosinase and Sox 10. No staining for TTF-1, carcinoembryonic antigen (CEA), pancytokeratin AE1/AE3 or for cytokeratins CK7 and CK5&6 is seen in tumor cells. The features are of metastatic malignant melanoma.
FINAL DIAGNOSIS: Metastatic malignant melanoma.