ABSTRACT

Background

Brain tumours are relatively common neurosurgical conditions. Variable patterns have been described in the literature. This study seeks to unravel the pattern of intracranial tumours in Korle Bu Teaching Hospital (KBTH) based on patient demographics, clinical presentation, spatial distribution of tumor and histological findings.

Method

Study design is retrospective, descriptive. Data was obtained from theatre and ward records of patients treated at the neurosurgery unit of Korle Bu Teaching Hospital between January 2010 to December 2015, and histology reports obtained from the histopathology unit. Patients with intracranial tumours without definitive histological diagnosis were excluded. Histological and demographic patterns of tumours were analyzed with SPSS version 21.

Results

Preliminary result shows that of the 102 histologically diagnosed brain tumours, out of 335 brain tumour cases seen in the period under review, 58 (56.9%) were females and 44 (43.1%) were males. Glioma were the commonest intracranial tumours – 39(38.2%) followed by Meningioma with 37(36.2%) and pituitary adenoma – 9(8.8%). Astrocytoma was the commonest type of Glioma comprising 30(77%) of the 39 cases. Meningotheliomatous meningioma was the commonest type of meningioma with 11 (29.7%) of 37 cases. Of the 39 Gliomas 17(43.6%) were males and 22(56.4%) were females, while for the Meningioma 17(46%) were males and 20(54%) were females. The commonest symptom was headache (64%) and the commonest tumour location was supratentorial. The crude incidence rate of intracranial tumour in this study was 1.34 per 100,000 population per year.

Conclusion

Intracranial tumours may be relatively common in Ghana but grossly underdiagnosed due to lack of an efficient national surveillance programme and tumour registry. Gliomas are the commonest. Overall females are more commonly affected than males, including both gliomas and meningiomas.

Key words: Histological diagnosis, Intracranial tumours, Korle Bu Teaching Hospital.

INTRODUCTION

Intracranial tumours include tumours arising from the brain or its surrounding tissues. Intracranial tumours remain a major cause of morbidity and mortality worldwide. The annual, global, age standardized incidence of primary malignant intracranial tumours is approximately 3.7 per 100,000 for males and 2.6 per 100,000 for females.[7] In the US the incidence rate of all primary malignant and non-malignant brain and CNS tumours between 2008 to 2012 was 21.97 cases per 100,000, the rate being higher in females (23.95/100,000 for a total count of 206,565 incident tumours) than males (19.82/100,000 for a total count of 150,271 incident tumour).[2] They are commoner among Caucasians.[5] Gliomas are the commonest group of intracranial neoplasms in both adults and children.[5,12] Gliomas are commoner in males while meningiomas are commoner in females.[5,8]
Outcome of intracranial tumours varies with tumour type, location, stage at diagnosis, age of patient, functional performance score and extent of tumour resection. Patients with intracranial tumours in Africa typically have delayed diagnosis due to late presentation, which has been reported to be 2 years on average,[8] thus making prognosis bleak. Various institution-based epidemiology of intracranial tumours have been reported in several places in Africa,[11,17,6,13] but the true incidence in sub-Saharan Africa is not known,[4] thus proper health budgeting and planning is far from optimal. There is very limited data on the patterns of intracranial tumours in Ghana thus the objective of this study is to determine the pattern of intracranial tumours in neurosurgical patients that present in Korle Bu Teaching Hospital, based on mode of presentation, patients’ demographics, spatial distribution and histological characteristics. This may be extrapolated to the Ghanaian population as Korle Bu Teaching Hospital is the foremost neurosurgical centre in Ghana where majority of the intracranial tumour patients are referred.

MATERIALS AND METHODS

This study is a retrospective, descriptive study based on data obtained from the hospital records of patients with intracranial tumours, diagnosed using Computed Tomography scan and/or Magnetic Resonance Imaging and treated in Korle Bu Teaching Hospital between January 2010 and December 2015. Korle Bu Teaching Hospital is the foremost teaching hospital in Ghana and the third largest teaching hospital in Africa, with a bed capacity of 2000[9]. Majority of the intracranial tumour cases in the country are treated in this hospital, being the national referral centre. An average of 2 new cases of intracranial tumour is seen at the neurosurgical clinic of the hospital every week besides those that present at the emergency room. There are three other centres where very few brain tumour surgeries are done in Ghana.
Data were obtained from ward records, theatre records and histopathology records of the hospital. Records of all the patients who have undergone different types of surgery for intracranial tumours were obtained from the theatre register of the hospital. Only those with histologically diagnosed tumours were included in the data analysis. These data included patient demographics (age and gender), clinical information, and histopathological type of the cancer.
The population of Ghana during the study period, estimated to be 25,000,000 from the 2012 census,[18] was taken as the average of the mid-year estimates for 2010 to 2015. The crude incidence rate was calculated from the total number of cases that presented at the Korle Bu Teaching hospital over the total population multiplied by 100,000, and expressed as the number of cases per 100.000 population per year. The population of Accra is estimated to be 2.27 million.[19]
Data were summarized using percentages, tables and charts, and analysed with SPSS version 21.

RESULTS

A total of 335 patients with intracranial tumours were seen in the period under review out of which 274 had surgical interventions ranging from stereotactic biopsy to open excision biopsy and ventriculoperitoneal shunting. 102 of these had histologically confirmed tumour described according to the WHO classification of Nervous system tumours. The overall gender distribution is shown in Table 1.

Table 1: Overall Gender distribution of intracranial tumours seen between 2010 and 2015.

Table 2: Tumour type and gender distribution

Histological distribution of the tumour is as shown on Table 2. Glioma is commonest with 38.2%, slightly higher than meningioma accounting for 36.2% of tumours seen. Pituitary adenoma and metastatic tumours account for 8.8% and 7.9% respectively. In all the aforementioned tumours females tend to have slight preponderance compared to males, but markedly so in the metastatic group with three-quarter being females. Overall, there were also more female patients with intracranial tumours.
A breakdown of the WHO histological types and age distribution is as shown on Table 3 below.

Table 3: Histological type and age distribution

Tumour distribution based on intracranial location is shown in Table 4 below.

Figure 1

Table 4: Tumour distribution based on location

The distribution of meningioma based on location is as shown on Figure 1. Convexity meningioma is the commonest making up 15 of 37 cases, followed by sphenoid wing meningioma and parasagittal meningioma with 8 and 6 respectively.

Figure 2

Table 5 below shows the commonest symptoms and signs in these patients with intracranial tumours. The percentages were calculated based on 62 patients with detailed symptomatology.

Table 5: Main symptoms and signs

DISCUSSION

Intracranial tumours are relatively common neurosurgical conditions and are associated with high morbidity and mortality. Patterns of distribution of these tumours vary across the globe. This study sought to determine the pattern of intracranial tumours in neurosurgical patients with intracranial tumours who presented at Korle Bu Teaching Hospital, Accra, Ghana for treatment between January 2010 and December 2015. 102 histologically diagnosed intracranial tumours out of 335 radiologically diagnosed intracranial tumours were included in the study. Gliomas were the commonest tumour type accounting for 38.2% of intracranial tumours followed closely by meningioma (36.2%). This is in keeping with findings in other studies.[8,11,17,6,13,15,3] Although gliomas are reported to be commoner in females, there was a slight female preponderance in this study, which is similar to an earlier publication in Tema, Ghana by Andrews et al.[1] This may be the true picture or just a reflection of the fact that females tend to seek medical treatment more than men with similar conditions in Ghana.
Meningioma was commoner in females as reported in other studies.[2,4,12, 8,11,17,6,13,15,3] It is also worthy of note that pituitary adenoma, metastatic tumours and craniopharyngioma, which followed gliomas and meningiomas in that order, in terms of prevalence, were all slightly commoner in females. The total number of intracranial tumours seen over the study period also showed slight female preponderance [Table 1] similar to the findings by Soyemi SS et al[17].
Glioblastoma and pilocytic astrocytoma were the commonest gliomas with the former commoner in the > 45 years age group similar to the CBTRUS study,[2] and the latter in the under 16 years age group, making pilocytic astrocytoma the commonest paediatric intracranial tumour, followed by medulloblastoma and ependymoma in this setting. Yusoff et al [20] reported a lower age bracket of 15-45 years as being the commonest age for glioblastoma in rural north east Malaysia. The mean ages for pituitary adenoma and metastatic tumours were similar to reported age groups.
Based on spatial location, supratentorial sites accounted for nearly three-quarter (77.5%) of tumour locations as against 22.5% for infratentorial. Mostly paediatric tumours – pilocytic astrocytoma, medulloblastoma and ependymoma were located infratentorially. Adult tumours, including metastatic tumours were mostly located supratentorially. 97.3% of meningiomas were located in the supratentorial region and convexity meningioma (40.5%) predominated, followed by sphenoid wing (21.6%) and parasagittal meningiomas (16.2%) respectively.

Tuberculoma have been reported to mimmick malignant tumours[14,16,10] but we have not found this to be common among our patients.
Headache (66.1%) was the commonest symptom as seen in other studies[8], closely followed by visual disturbance (33.9%), hemiparesis (24.2%) and seizures (19.4%). Some studies reported focal neurologic deficit as the commonest clinical presentation.[15,3]
The crude incidence rate of intracranial tumour in this study was 1.34 per 100,000 population per year. This may be a gross underestimation of the true incidence since this data was collected from one institution. Moreover, it is almost impossible to determine the true incidence of intracranial population in Ghana since some of the patients with intracranial tumours do not present to the hospital but seek alternative care in prayer camps and with herbal remedy providers. A few are treated in other health facilities within and outside the country. This crude incidence is higher than the 0.44 per 100,000 reported in the Malay population.[20]

The limitation of this study is the relatively small sample size, the low histological diagnosis rate and incomplete data in some patients’ records.

CONCLUSION

Intracranial tumour may be relatively common in Ghana but grossly under diagnosed. The crude incidence rate of intracranial tumour in this study was 1.34 per 100,000 population per year. Glioma was the commonest intracranial tumour in this setting followed by meningioma. Females were more affected by glioma, meningioma, pituitary and metastatic tumours than males. Overall females were more at risk of intracranial tumours than men in this setting. Astrocytoma was the commonest type of Glioma. Meningotheliomatous meningioma was the commonest type of meningioma.

Age of patient at diagnosis varied with the tumour with the youngest age affected being 1 year and the oldest age 73 years. Pilocytic astrocytoma was the commonest paediatric tumour, followed by medulloblastoma and ependymoma. The commonest symptom was headache and the commonest tumour location was supratentorial. Convexity meningioma was the commonest location of meningioma.