Malignant melanoma of skin, unspecified [C43.9], Reason for Study: ^Reason: metastatic melanoma concern for mets to brain History: metastatic melanoma There is no evidence of acute ischemic or hemorrhagic lesion. There is no abnormal enhancement.There is a 13 mm x 14 mm sized well-circumscribed subcutaneous lesion at the right occiput which shows low signal intensity on T2 and low signal intensity T1 with the minimal peripheral enhancement. In addition, there is evidence of patchy enhancement on surrounding subcutaneous tissues. The MR characteristics of this lesion is nonspecific but may indicate the lesion contains calcification, fibrosis or hemosiderin with some inflammatory changes. Differential diagnosis include epidermal inclusion cyst, inflammatory changes of subcutaneous lymph node. Possibility of metastatic lesion is less likely.The ventricles, sulci and cisterns are unremarkable. There is no intracranial mass, mass effect, edema, midline shift, intra or extra-axial fluid collection/hemorrhage, restricted diffusion/acute ischemia, or abnormal contrast enhancement. The midline structures and cranial-cervical junction are normal. Normal flow voids are identified in the major intracranial vessels. The paranasal sinuses and mastoid air cells are clear.
1. No evidence of acute ischemic or hemorrhagic lesion. No abnormal enhancement.2. Well-circumscribed subcutaneous lesion which is nonspecific in terms of MR characteristics.