Glioblastoma multiforme recurrence on skin and subcutaneous tissue: a case report

Glioblastoma multiforme (GBM) is the most common malignant primary central nervous system (CNS) tumor. It presents an aggressive pattern, with a tendency for intracranial progression despite optimal treatment. On the other hand, metastases and manifestations outside the CNS are exceptional, and very few cases have been described. The authors submitted a case of a 48-year-old male diagnosed with a left parietooccipital GBM isocitrate dehydrogenase (IDH) wild-type, non-methylated O6-methylguanine-DNA methyltransferase (MGMT). Six months after surgical treatment, followed by a chemotherapy (CT) and radiotherapy scheme, he developed a few subcutaneous erythematous nodules within the surgical scar. A punch biopsy confirmed the histopathology of GBM. The CT scan showed concomitant intracranial progression. We ruled out systemic metastases. As the performance status was good [Karnofsky Performance Status 90 (KPS 90)] and the subcutaneous implants were growing rapidly, limiting the quality of life, we decided to perform palliative surgery to remove the implants. The result was good. Unfortunately, the patient worsened during the following week, after ruling out medical complications, we attributed the worsening to cerebral tumor swelling, revealed in the CT scan, as unresponsive to steroids. He passed away a few days later. Based on the analysis of our case, we intend to provide useful information for the approach to this peculiar manifestation of GBM.