Prevalence and socio-demographic characteristics
The aim of this study was to determine the epidemiological profile of BTs in a referral hospital in Cameroon. A total of 150 cases were recorded during this period giving an annual frequency of 15 cases per year. In Nigeria, Olasode et al. reported 210 cases of intracranial neoplasms (annual incidence of 21 cases per year) in a retrospective study carried out over 11 years at the University College Hospital of Ibadan [5]. Eyenga et al. reported a frequency of 6.3% [9]. This annual frequency does not necessarily reflect the reality. If this hospital is the main referral hospital, other health facilities in Douala (Cameroon) provide neuro-oncological care of patients. Moreover, some of the patients may not come to this hospital because of limited financial resources.
This study found a slight male predominance. Soyemi et al. [11] reported a similar finding in a tertiary health facility in Nigeria. However, this differs from what Enow Orock et al. [10] obtained from the cancer registry in Yaoundé and pathological unit of Buea Regional Hospital. They reported a female predominance 62.5%. Literature reports a slight male predominance [10].
Most of patients in this study were young adults (24–54 years). Olasode et al. observed that the peak age group for intracranial tumors in adults was 25–30 years and Soyemi et al. had similar findings (21–30 years) [5, 11]. All of these findings are quite similar to our results. This age group represents the active population of our study area.
Histological types of brain tumors
Primary BTs were the most common types in our patients. Olasode et al. found similar results with primary tumors making up 77% of the cases and metastases 23% of intracranial neoplasms [5].
Meningiomas were found to be most frequent in patients within the ages of 25–54 years. WHO grade I were the most common histological subtype in our series. Eyenga et al. and Mwangombe et al. [9, 12] found similar findings. Other studies reported astrocytomas to be more frequent [10, 13]. The slight female predominance among cases of meningioma is similar to the results of Mwangombe et al. in Kenya [12].
Gliomas accounted for about one-third of cases in this study. This is very similar to the 33% reported by Olasode et al. in 2000 [5]. Astrocytomas were the most common type, followed by oligodendromas, and ependymomas. More than half of astrocytomas were grade IV. Similarly, Mwangombe et al. [12] reported 22 cases of glioblastomas (55%) in 2006. Andrews et al. found high-grade astrocytoma to be the most common intracranial neoplasm in their study (23%) [13]. Literature reports that astrocytomas make up 50% of brain tumors and glioblastomas are the most frequent form of astrocytoma [5, 12, 13]. Oligodendromas are far less frequent than astrocytomas in this study. Very similar findings were reported by some authors [5, 14].
Ependymomas represented 2% of all intracranial neoplasms in this study which is comparable to the 1.1% in a Caucasian series [15]. In USA, ependymoma is more common in children than adults [16]. We found ependymoma only in adults. Medulloblastoma is the commonest intracranial neoplasm in American children [17]. In the present study, it was the second most common neoplasm after astrocytoma. Three adult cases of medulloblastoma were recorded, which is similar to the reports in USA [7].
Pituitary adenomas were the third most common type in this series. This is comparable to the 17.8% obtained by Cushing et al. [15]. Lower frequency of pituitary adenomas (9.86%) has been observed by Mwangombe et al. [12]. Tumors of the pineal region accounted for 5.3% namely pineoblastomas, pineal carcinomas, and pineocytomas. A study done in Japan indicates that these tumors represent 3.5% of intracranial tumors [18]. Acoustic neuromas were one of the least frequent tumor types in our population. With only two cases found, the annual incidence is far less than the 1 to 20 per 100,000 reported by Edward et al. in 2006 [19].
About two-thirds of brain metastases were above 55 years; no case of brain metastases was reported by Soyemi et al. in Nigeria [11]. Half of brain metastasis originated from lung cancers. One-third of cases were breast cancers. These results differ from the report of Olasode et al. [5] who found choriocarcinomas as main source of metastases followed by Burkitt’s lymphoma. This difference may be related to the increasing trends in incidence and prevalence of lung and breast cancers over the years [20, 21].
Burkitt’s lymphoma is mainly a pediatric tumor and this study does not show pediatric involvement in brain metastases [22].
Clinical manifestations
Commonest clinical features were signs of raised ICP including: headache, blurred vision, vertigo and vomiting. These signs can be associated with mass effect on the brain by tumor. Other signs included seizures, motor deficits, and cognitive deficits. These could be attributed to direct effect on critical brain areas by the tumor, mass effect, leptomeningeal spread and compromise of vascular flow to these areas [23]. These proportions agree with literature reports which indicate signs of raised intracranial pressure as most common clinical presentations of brain tumors [2, 9, 10, 15, 24].
