Skin Metastasis of Glioblastoma Multiforme: A Case Report and Literature Review.

Abstract

We present the case of a 75-year-old woman with a history of glioblastoma multiforme (GBM) who had undergone craniectomy and resection 7 months earlier and was participating in a clinical trial of nivolumab versus placebo. The patient had been referred from the oncology to the dermatology department for an erythematous mass (3 × 4 cm) with a crusted and ulcerated surface located in the right parietal region, close to the craniectomy scar (Fig. 1). The patient provided the results of a magnetic resonance imaging (MRI) study performed the previous day in which no continuity solution was evident in the bone. A biopsy was performed on suspicion of skin metastasis of GBM, and revealed marked diffuse dermal infiltrate consisting of mononuclear cells with hyperchromatic nuclei and marked pleomorphism. Immunohistochemistry revealed positive staining for CD10, protein gene product (PGP) 9.5, and glial fibrillary acid protein (GFAP), indicating a probable neural origin (Fig. 2). Staining for S100, HMB45, cytokeratin 20, and CD99 was negative. One month later the patient presented to the oncology department with absence seizures. Imaging tests revealed subacute hydrocephalus secondary to the initial surgical intervention. There was no possibility of placing a ventriculoperitoneal shunt. Interestingly, no changes in either the lesion or the perilesional edema were observed relative to the initial MRI findings. Given the patient’s poor progression, it was decided to administer symptomatic palliative treatment. Although GBM is the most common malignant brain tumor, extracranial metastasis is uncommon, and has been reported in only 2.7% of 148 patients with a histological diagnosis of glioma who were followed up for 5 years. The most common sites of metastasis are the lung, pleura, and lymph nodes; skin metastasis is more rare. In the current literature there are 7 reports of skin metastasis of cerebral glioma grades III to IV (Table 1). Ours is the first reported case of skin metastasis of GBM without recurrence of intracranial disease, which is usually observed in patients with a history of invasive surgical procedures, suggesting a fundamental role of iatrogenic seeding. However, in 10% of patients extracranial metastasis occurs in the absence of previous surgical interventions or at a site