Discussion
Pulmonary embolism (PE) is a major cardiovascular disease which could be potentially life-threatening (1). Pre-existing malignancy is one of the most common etiology in recurrent forms. (4). The most frequent occult malignancies during PE involved the lung, gastrointestinal tract, breast, and uterus (5). These malignancies are generally diagnosed at the advanced stage of the disease (8). The pathophysiology of malignancy associated with thromboembolism include : hypercoagulable state due to many factors including release of inflammatory cytokines, activation of the clotting system, expression of hemostatic proteins on tumor cells, inhibition of natural anticoagulants, and impaired fibrinolysis (9). Brain tumors like ovary and pancreatic cancers even if rare in terms of prevalence are strongly associated with thromboembolic events (10). This is illustrated by the fact that 11-20% of patients with brain tumors have pulmonary embolism and the median time to develop the disease in generally 6.5 years after the diagnosis of the tumor (11). Our patient was followed for a depression since 5 months before the diagnosis of the second episode of pulmonary embolism. We think that the first episode of pulmonary embolism during childhood could be due to a provoked cause (knee trauma). Glioblastoma is known as the main brain tumor and the most associated with pulmonary embolism (11). The radiological presentation of the mass evoked this diagnosis, even if the final diagnosis is done by histopathologic studies. At the early stage of the disease, MRI of the brain is the most sensitive tool for the diagnostic of Glioblastoma isointensity to hypointensity on T1WI, hyperintense ill-defined lesions on T2WI, little or no mass edema, and no contrast enhancement (12). CT-Scan could evoked hypervascularised brain tumor, but the difference between primitive lymphoma or glioblastoma is difficult by imaging (13). Knowing that the patient was immunocompetent and the lesion was polylobular and heterogenous contrary to lymphoma we have retained the diagnosis of glioblastoma. But this diagnosis will be well investigated by the neurosurgical team. The presence of signs of herniation signify that the tumor was advanced. This case suggest that the physician should be more aware and thoroughly examine young patients with pulmonary embolism in order to exclude potential life-threatening conditions like malignancy.