Squamous cell carcinoma of the scalp , status post surgery at outside hospital. There are postoperative findings in the left occipital scalp, where there is a wide skin defect at the incision that extends to the underlying dura. There is diffuse patchy enhancement along the margins of the defect and more discrete subcentimeter nodules inferior to the defect. There is also diffusely enhancing tissue between the scalp flap and underlying dura, especially posteriorly, where it measures up to 15 mm in thickness. There is patchy bone marrow enhancement along the margins of the craniotomy and the underlying dura is also diffusely thickened, In addition, there is wispy enhancement along the surface of the underlying left cerebellar hemisphere, with scattered areas of high T2 signal and restricted diffusion. There is also a small area of encephalomalacia in the left cerebellar hemisphere. There are also areas of encephalomalacia in the right corona radiata, right basal ganglia, and left thalamus. There is a background of patchy cerebral white matter T2 hyperintensity. The ventricles are normal in size. There is no midline shift. There are bilateral lens implants. There is mucosal thickening and retention cyst formation in the left maxillary sinus.
1. Postoperative findings in the left occipital scalp, where there is an open would that extends to underlying dura with diffusely enhancing tissue between the scalp flap and underlying dura, which may represent tumor and/or inflamed or granulation tissue, with what may represent adjacent osteomyelitis and pachymeningitis or tumor infiltration. Subcentimeter nodules inferior to the defect may represent mildly reactive lymph nodes, although neoplastic deposits remain a potential consideration. Wispy enhancement along the surface of the underlying left cerebellar hemisphere, with scattered areas of high T2 signal and restricted diffusion may represent cerebritis with ischemia.2. Chronic lacunar infarcts in the left cerebellar hemisphere, right corona radiata, right basal ganglia, and left thalamus.