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.