1. PATHOLOGY OF BRAIN
TUMOURS - THE SUBREGIONAL
EXPERIENCE
E.E.U. AKANG, MBBS
Professor of Pathology, University of Ibadan, Nigeria
Consultant Pathologist, Department of Pathology, University
College Hospital, Ibadan, Nigeria
CLINICAL NEUROSCIENCE REVIEW CONFERENCE
AUGUST 8 - 10, 2011
IBADAN, NIGERIA

2. E k’abo! Welcome to Ibadan!

3. Introduction 1
• Central nervous system (CNS) tumours
are a diverse group of neoplasms
• Each neoplasm has distinctive biology,
treatment and prognosis
• High-grade CNS neoplasms are among
the most aggressive and intractable
types of cancer

4. Introduction 2
•Cancer is the leading cause of
nd
death in developed and the 2
most common cause in developing
nations
•Age-standardised mortality rates
for CNS tumours is 3.6 in
developed and 2.9 per 100,000 in
developing nations

5. Historical background
•CNS tumours were believed to be rare in
native Africans up until half a century ago
•Expanding general/specialist medical
services have led to increasing
recognition of CNS tumours
•Most of the early reports from the sub
region have been clinical neurosurgery
series

6. 144 million population
35,000 medical doctors
<500 pathologists
Per capita (p.c.) income $300
Health budget $50 p.c.
307 million population
814,000 medical doctors*
*How many of these are
Nigerians?
20,000 pathologists*
Per capita (p.c.) income
$39,000
Health budget $2,250 p.c.
6

7. Early studies in Africa
•Necropsy-based studies were the 1st
reports of CNS tumours in tropical Africa
•Strachan, 1934- South Africa- less
common in Bantus than other races
•Davies, 1957- 6 gliomas among 2162
PMs- not uncommon
•Jackson & Okubadejo, 1963- wellillustrated report of 13 CNS tumours
among 3489 PMs- uncommon

8. Meningioma
WAMJ 1963; 12:251-263
3 meningiomas
2 astrocytomas
2 pituitary adenomas
1 pinealoma

9. WAMJ 1963; 12:251-263
Case reported as medulloblastoma
3 cases of medulloblastoma14 yr F- frontal lobe;
30 yr M- Lt thalamus, cerebellum and midbrain;
4 yr F- basal ganglia and optic n.
14 yr Fleft frontal lobe
mass
Could this be a
PNET or an
anaplastic
astrocytoma?

10. WAMJ 1963; 12:251-263
Case reported as ependymoma
15 year old
male with
fibrosarcoma
of thigh with
lung
metastases
and dura
based
intracranial
tumour

11. Later studies
Odeku & Janota 19673 yrs after establishment of Neurosurgery at UCH,
Ibadan- “not so rare”
48 intracranial masses
44 neoplasms; neurogenous neoplasms (47.7%),
meningiomas (22.9%), sellar region (15.9%)
Ohaegbulam et al 198043 intracranial neoplasms from Enugu
Gliomas (23.2%), sellar region (20.9%), meningioma
(18.6%)

12. Other early African studies
• Kasili et al 1971- Kenya
97 intracranial tumours; gliomas 45%, meningiomas
28%
• Collomb et al 1973- Senegal
187 intracranial neoplasms and 33 inflammatory
masses
Gliomas, meningiomas, sellar region tumours
• Sorour et al 1973- Egypt
Two series 291 clinical and 377 autopsy
Gliomas, meningiomas- high incidence

13. Ibadan- 1980-1997
East Afr Med J 2000; 77:1-5
Olasode et al 20002nd and 3rd generations of Ibadan neurosurgeons
210 histologically confirmed CNS neoplasms- 135
(64.3%) adults & 75 (35.7%) children
Gliomas most common, followed by metastases
(choriocarcinoma and Burkitt’s lymphoma)
Sellar region tumours predominate in children

14. Ibadan- 1991-2007
Sahabi 20083rd generation of Ibadan neurosurgeons
Progressive increase in CNS tumour rates
356 histologically confirmed CNS neoplasms264 (74.2%) adults & 92 (25.8%) children
Gliomas most common, followed by
meningiomas. Female predominance in
meningiomas; Reduced metastases, with decline
in choriocarcinoma

15. Sahabi, 2008

16. Gender distribution among tumour groups

18. Pilocytic astrocytoma
Sahabi, 2008

19. Gemistocytic astrocytoma
Sahabi, 2008

20. Anaplastic astrocytoma
Sahabi, 2008

21. Oligodendroglioma
Sahabi, 2008

22. MeningiomasSahabi, 2008
HISTOLOGICAL HISTOLOGICAL
TYPES
SUBTYPES
Meningioma
Mesenchymal
tumours
Other
WHO GRADE
TOTAL
I
II
III
Secretory
Anaplastic
Atypical
Angiomatous
Psammomatous
Meningothelial
Fibroblastic
Transitional
3
0
0
2
5
21
8
45
0
0
3
0
0
0
0
0
0
7
0
0
0
0
0
0
3
7
3
2
5
21
8
45
Haemangiopericytoma
0
3
1
4
Haemangioblastoma
3
0
0
3

23. Odebode et al, 2002
Unpublished observations
Morphological
variants
Nigeria
(1972)
N=38
Nigeria
(2002)
N=60
Turkey S’Arabi Canada
(1997) a (1996) (1983)
N=203 N=131 N=114
USA
(1982)
N=51
Norway
(1974)
N=256
Transitional
Meningothelial
44.7
55
26.6
19
30.5
23
34
42.1
34.2
37.3
35.3
6
52
Psammomatous
Fibrous
Angiomatous
23.7
7.9
5.3
1.7
1.7
1.7
7
26
3.5
3
23
5
20.2
0.9
9.8
7.8
-
14
5
Mixed patterns
18.4
-
-
-
-
-
23
Sclerosing
-
-
-
10.7
-
-
-
Chordoid
-
-
-
0.8
-
-
-
Hemangiopericytoma
-
8.3
-
-
-
-
-
Papillary
-
-
-
-
-
9.8
-
Anaplastic
-
5.0
13
-
2.6
-
-
Atypical
-
-
1
-
-
-
-

24. Meningioma- secretory
Sahabi, 2008

25. Meningioma- transitional
Sahabi, 2008

26. Craniopharyngioma
Sahabi, 2008

27. Metastatic CNS neoplasms
Sahabi, 2008

28. Metastatic choriocarcinoma
Sahabi, 2008

29. Lagos University Teaching Hospital

30. LAGOS- 2001-2011
Awelimobor 20111st and 2nd generation of Lagos neurosurgeons
Progressive increase in CNS tumour rates
110 CNS neoplasms- 76.4% adults & 23.6%
children
Meningioma (30.9%), pituitary adenoma
(20%) and astrocytic tumours (19%).
Metastases in 3.5%.

31. Craniopharyngioma
Awelimobor, 2011

32. PAEDIATRIC CNS NEOPLASMS 1
• Age standardised incidence rates for
childhood CNS neoplasms is 25-40
per 106 in developed countries and
<15 per 106 in developing nations
• Due partly to under ascertainment
and partly to racial factors

33. PAEDIATRIC CNS NEOPLASMS 2
IBADAN
•Aghadiuno et al- 89 CNS neoplasms (1960-1982)Astrocytoma, medulloblastoma, ependymoma and
oligodendroglioma
•Olasode- astrocytoma, craniopharyngioma and
medulloblastoma
•Overall increase with fewer Burkitt’s cases
ENUGU- Izuora et al
Craniopharyngioma (38%), astrocytoma and
medulloblastoma (14% each)

34. PAEDIATRIC CNS NEOPLASMS 3
• Karkouri et al reviewed 542 CNS
neoplasms in Morrocco
• Astrocytoma and medulloblastoma
were most common
• Emphasised the need for population
based registry to assess true burden of
these neoplasms

35. INTRAOPERATIVE CONSULTATION
A primary role of pathologist in patient
management
-Gross examination
-Frozen section
-Cytology
Awelimobor 2011100% concordance rate between cytological and
frozen section diagnosis, as well as between frozen
section and routine paraffin embedded tissue
diagnosis

36. Glioblastoma- cytology, Frozen section and
permanent section
Awelimobor, 2011

37. Pituitary adenoma- cytology and frozen section
Awelimobor, 2011

38. Meningioma- cytology, Frozen section and
permanent section
Awelimobor, 2011

39. COMPARISON OF SELECTED AFRICAN SERIES
TUMOUR
TYPES
Ibadan
1957-1969
N = 116*
Ibadan
1980-1990
N = 210
Ibadan
1991-2007
N = 356
Lagos
2001-2010
N = 110
Senegal
1960-1971
N = 187
Kenya
1968-1971
N = 97
Egypt
1956-1962
N = 315*
53 (25.3%) 88 (24.7%) 21 (19.1%) 64 (34.2%)
33 (34%)
99 (31.4%)
Astro
15 (12.9)
Oligo
1 (0.9)
8 (3.8)
8 (2.2)
1 (0.9)
0 (0)
0 (0)
5 (1.6)
Ependymal
6 (5.2)
1 (0.5)
11 (3.1)
3 (2.7)
6 (3.2)
5 (5.2)
28 (8.9)
Choroid
0 (0)
0 (0)
1 (0.3)
2 (1.8)
3 (1.6)
1 (1)
3 (9.5)
Neuronal/
Glial
0 (0)
0 (0)
8 (2.2)
0 (0)
0 (0)
0 (0)
0 (0)
Pineal
5 (4.3)
0 (0)
2 (0.6)
1 (0.9)
0 (0)
1 (1)
13 (4.1)
Embryonal
6 (5.2)
8 (3.8)
25 (7)
5 (4.5)
5 (2.7)
4 (4.1)
15 (4.8)
Cranial
nerve
1 (0.9)
0 (0)
1 (0.3)
1 (0.9)
4 (2.1)
3 (3.1)
27 (8.6)
Meningeal
19 (16.4)
24 (11.4)
104 (29.2)
37 (33.6)
35 (15.9)
24 (24.7)
75 (23.8)
Lymphoma
0 (0)
0 (0)
1 (0.3)
0 (0)
0 (0)
0 (0)
0 (0)
2 (1.7)
3 (1.4)
1 (0.3)
0 (0)
0 (0)
0 (0)
0 (0)
Sellar
region
24 (20.7)
55 (26.1)
78 (21.9)
31 (28.2)
14 (7.5)
13 (13.4)
28 (8.9)
Metastatic
21 (18.1)
48 (23)
31 (8.7)
5 (4.5)
26 (13.9)
10 (10.3)
14 (4.4)
Germ cell

40. CONCLUDING REMARKS
•Pathologists in the sub region faces enormous
challenges in terms of diagnostic facilities
•Biologic characteristics of CNS neoplasms in
developing countries have been discussed
•Expansion of adult/pediatric
neurologic/neurosurgical facilities requires
increased sophistication of routine laboratory
diagnostic methods
•This can be facilitated by training and research
linkages between centers in developing and
developed countries.

41. LIST OF REFERENCES

42. Thanks for listening!
Have a safe trip home!
O d’abo!