What is the most likely pathology for this solid left temporal lesion on MRI brain?
Answer
Congratulations to all those who guessed malignant melanoma. Primary CNS melanoma is rare, while metastatic melanoma is the third most common brain metastasis. It typically appears hyperintense on T1 due to melanin as well as blood and hypointense on T2. It shows contrast enhancement, which can be appreciated in the image above. SWI signal loss is seen in 42% cases where hemorrhage is present because melanin itself does not have a strong diamagnetic effect.
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