A subcutaneous mass due to a glioblastoma which invaded and destroyed the bone: A case report

Background: Glioblastoma multiforme (GBM) is the most common and aggressive primary malignant brain tumor. However, it rarely invades and destroys bone. We report the first case of GBM of a very old patient, which eroded the dura and bone and finally resulted in a large facio-cranial subcutaneous lesion in the absence of prior surgery or radiation. Case description: A 93-year-old woman was presumed with a low-grade glioma (LGG), and the lesion was followed up with magnetic resonance imaging (MRI). Serial monitoring revealed no tumor growth until 2 years later, when the patient was admitted to our institution for anorexia and lack of spontaneity and flow of conversation. On admission, she oftentimes complained of severe right forehead skin pain. Computed tomography (CT) revealed enhancing mass lesions in the right frontal lobe and bone destruction. Upon inspection and palpation, a soft and swelling subcutaneous mass was evident at the forehead, the site of bone destruction. Contrast-enhanced MRI revealed ring-enhancing lesions with irregular borders, and the malignant transformation of LGG into GBM was suspected. The patient had severe skin pain at the region of the subcutaneous mass, so tumor resection of the subcutaneous mass was performed for removing the pain and a definitive diagnosis. The pathological diagnosis was isocitrate dehydrogenase (IDH)-mutated glioblastoma. Immunostaining revealed that the tumor was positive for IDH-1 and p53mutations but negative for ATRX. The patient died due to aspiration pneumonitis. Conclusions: We report a first case of GBM in a very old patient untreated with surgery or radiation that invaded and destroyed the calvaria during the natural progression of the disease. Calvarial destruction without prior surgery or radiation in very old patients association with extra- and intra-axial neoplasm should include GBM in the differential diagnosis, although this is very rare