Hemangioblastomas are relatively rare tumors of the central nervous system, representing 1.5% to 2.5% of all intracranial tumors and 7% to 8% of all posterior cranial fossa (PCF) tumors [1] . They occur mainly in the cerebellar hemispheres in 76% of cases, making them the most common primary cerebellar tumor in adults [2] . Approximately 70% of cases are reported to be sporadic, and the remaining 30% are reported to be familial cases associated with LHL. It is estimated that 60% - 80% of patients with von Hippel-Lindau disease develop CNS hemangioblastoma during their lifetime [3] . Hemangioblastoma has an excellent prognosis with complete excision [3] . In imaging, CT is usually the first examination performed, it can provide important information; but MRI remains the examination of choice for the examination of the posterior cerebral fossa and its tumors, better specifying their cystic and solid components [4] . We report the case of a hemangioblastoma discovered incidentally on CT scan in order to study the value of CT scan in the management of this pathology.

This was a 38-year-old patient with no known medical or surgical history, consulted at the University Hospital Center of the Institute of Tropical Ophthalmology of Africa (CHU-IOTA) for visual loss, occipital intense headache and bilateral eyelid swelling, non-painful progressively developing over a period of 4 weeks following a wasp sting since September 2023. There were swellings and redness in the skin following this wasp sting, which left skin spots after local treatment with hydrocortisone ointment. He had no vomiting. Given the persistence of ophthalmological clinical signs, the patient was specified for an orbito-cerebral computed tomography (CT) scan in the radiology and medical imaging department of the Marie Curie Medical Clinic in Bamako, Mali. Given these clinical signs, the patient was referred for an orbito-cerebral computed tomography (CT) scan. This CT scan was performed using a 16-slice GE Optima multi-slice device from 2007. An acquisition without injection of contrast product (CSP) and an acquisition with CSP injection was performed. The CT scan revealed a thin-walled cystic formation not enhanced by injection of contrast product measuring 61 × 36 mm on an axial section at the level of the posterior cerebral fossa in the right cerebellar region, it contained a spontaneously dense 08 × 05 mm mural nodule that enhanced intensely after injection of CSP ( Figure 1 ).

This cystic mass exerted a mass effect on the fourth ventricle V4 responsible for a moderate dilatation of the supratentorial upstream ventricular system involving the lateral ventricles and the 3^rd ventricle with sign of transependymal resorption including spontaneous periventricular hypodensity ( Figure 2 ).

The patient was operated with good clinical and radiological evolution. Our patient had no more visual disturbance with headache resolution after one week postoperatively.

Hemangioblastoma is a benign tumor of the central nervous system that occurs most commonly in the cerebellum. The diagnosis of hemangioblastoma is based

mainly on histological and immunophenotypic features, with clinical, radiological and molecular information providing additional support [3] . Our patient was radiologically suggested and histologically confirmed. Immunophenotyping and molecular analysis were not performed in our case due to financial difficulty and the unavailability of these tests. In the various observations published in the literature the average age of the patients was 42.7 years, with a slight predominance for the male sex [1] . In our case, the subject was male and 38 years old. In our study, the symptomatology presented by our patient was considered secondary to the mass effect conditioning the symptoms of increased intracranial pressure (ICP) (headache, eyelid edema, visual disturbance). This result was comparable to that of the literature [1] . The most frequent location of these tumors in the literature was the posterior cranial fossa [3] . In our case, the tumor was in the posterior cerebral fossa more precisely at the right cerebellar level. CT scan allowed to evoke the diagnosis of hemangioblastoma in our case. The literature favors magnetic resonance imaging (MRI) as the examination of choice [1] . Our patient did not have MRI. CT scan was sufficient for the diagnosis of hemangioblastoma in our case. In the literature, this tumor presents as a cystic formation with a hypervascular intramural nodule whose CT imaging demonstrates isodensity with respect to the brain within the solid component. Calcification is generally absent. On magnetic resonance imaging, hemangioblastomas tend to appear as a hypoenti-T1 to isointense, a hyperintense T2 nodule with serpentine flow voids in the nodular part [3] [5] - [7] . Our patient had the intramural intracystic iso-dense hypervascular nodule after iodine injection. He had no calcification in our observation. CT has the advantage of being available and accessible in our country compared to MRI which is much more expensive and not available everywhere. The radiological differential diagnosis of hemangioblastoma in our daily practice is uncommon but can be done with glial tumors, particularly pilocytic astrocytoma which does not have a hypervascular mural nodule and is found in children. Brain metastases are less common in the posterior cerebral fossa and are enhanced in the periphery. On the other hand, histologically there were many differential diagnoses cited in the literature, such as Meningioma; Solitary fibrous tumor; Glalic neoplasms; Paraganglioma and Hemangioma, which have similar but different histological characteristics depending on the aspects [3] . Our case was confirmed histologically.

Hemangioblastoma is a benign neoplasm that can occur throughout the central nervous system, but the most common location is the posterior cranial fossa. It may be discovered incidentally. CT is usually the first test performed to suggest the diagnosis, but MRI remains the test of choice.

The patient had given informed consent and anonymity was maintained.