PATHOLOGY OF BRAIN TUMOURS - THE SUBREGIONAL

EXPERIENCEE.E.U. AKANG, MBBS

Professor of Pathology, University of Ibadan, NigeriaConsultant Pathologist, Department of Pathology, University

College Hospital, Ibadan, Nigeria

CLINICAL NEUROSCIENCE REVIEW CONFERENCEAUGUST 8 - 10, 2011

IBADAN, NIGERIA

E k’abo! Welcome to Ibadan!

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

Introduction 2•Cancer is the leading cause of death in developed and the 2nd 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

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

144 million population35,000 medical doctors<500 pathologistsPer capita (p.c.) income $300Health budget $50 p.c.

6

307 million population814,000 medical doctors* *How many of these are Nigerians?20,000 pathologists*Per capita (p.c.) income $39,000Health budget $2,250 p.c. 6

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- well-illustrated report of 13 CNS tumours among 3489 PMs- uncommon

MeningiomaWAMJ 1963; 12:251-263

3 meningiomas

2 astrocytomas

2 pituitary adenomas

1 pinealoma

WAMJ 1963; 12:251-263Case reported as medulloblastoma

14 yr F- left frontal lobe mass

Could this be a PNET or an anaplastic astrocytoma?

3 cases of medulloblastoma- 14 yr F- frontal lobe; 30 yr M- Lt thalamus, cerebellum and midbrain; 4 yr F- basal ganglia and optic n.

WAMJ 1963; 12:251-263Case reported as ependymoma

15 year old male with fibrosarcoma of thigh with lung metastases and dura based intracranial tumour

Later studiesOdeku & Janota 1967- 3 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 1980- 43 intracranial neoplasms from EnuguGliomas (23.2%), sellar region (20.9%), meningioma (18.6%)

Other early African studies• Kasili et al 1971- Kenya 97 intracranial tumours; gliomas 45%, meningiomas

28%• Collomb et al 1973- Senegal187 intracranial neoplasms and 33 inflammatory

masses Gliomas, meningiomas, sellar region tumours• Sorour et al 1973- EgyptTwo series 291 clinical and 377 autopsyGliomas, meningiomas- high incidence

Ibadan- 1980-1997East Afr Med J 2000; 77:1-5

Olasode et al 2000- 2nd and 3rd generations of Ibadan neurosurgeons210 histologically confirmed CNS neoplasms- 135 (64.3%) adults & 75 (35.7%) childrenGliomas most common, followed by metastases (choriocarcinoma and Burkitt’s lymphoma)Sellar region tumours predominate in children

Ibadan- 1991-2007Sahabi 2008- 3rd generation of Ibadan neurosurgeonsProgressive increase in CNS tumour rates356 histologically confirmed CNS neoplasms- 264 (74.2%) adults & 92 (25.8%) childrenGliomas most common, followed by meningiomas. Female predominance in meningiomas; Reduced metastases, with decline in choriocarcinoma

Sahabi, 2008

Gender distribution among tumour groups

Pilocytic astrocytomaSahabi, 2008

Gemistocytic astrocytomaSahabi, 2008

Anaplastic astrocytomaSahabi, 2008

OligodendrogliomaSahabi, 2008

Meningiomas-Sahabi, 2008

HISTOLOGICAL TYPES

HISTOLOGICAL SUBTYPES

WHO GRADETOTAL

I II III

Meningioma

Secretory 3 0 0 3Anaplastic 0 0 7 7Atypical 0 3 0 3Angiomatous 2 0 0 2Psammomatous 5 0 0 5Meningothelial 21 0 0 21Fibroblastic 8 0 0 8Transitional 45 0 0 45

Mesenchymal tumours Haemangiopericytoma 0 3 1 4

Other Haemangioblastoma 3 0 0 3TOTAL 87 6 8 101

Odebode et al, 2002Unpublished observations

Morphological variants

Nigeria(1972)N=38

Nigeria (2002)N=60

Turkey (1997)N=203

S’Arabia (1996)N=131

Canada (1983)N=114

USA (1982)N=51

Norway (1974)N=256

Transitional - 55 19 23 42.1 37.3 6Meningothelial 44.7 26.6 30.5 34 34.2 35.3 52

Psammomatous 23.7 1.7 7 3 - 9.8 -Fibrous 7.9 1.7 26 23 20.2 7.8 14Angiomatous 5.3 1.7 3.5 5 0.9 - 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 - - - -

Meningioma- secretorySahabi, 2008

Meningioma- transitionalSahabi, 2008

CraniopharyngiomaSahabi, 2008

Metastatic CNS neoplasmsSahabi, 2008

Metastatic choriocarcinomaSahabi, 2008

Lagos University Teaching Hospital

LAGOS- 2001-2011Awelimobor 2011- 1st and 2nd generation of Lagos neurosurgeonsProgressive increase in CNS tumour rates110 CNS neoplasms- 76.4% adults & 23.6% childrenMeningioma (30.9%), pituitary adenoma (20%) and astrocytic tumours (19%). Metastases in 3.5%.

CraniopharyngiomaAwelimobor, 2011

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

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

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

INTRAOPERATIVE CONSULTATIONA primary role of pathologist in patient management-Gross examination-Frozen section-CytologyAwelimobor 2011- 100% concordance rate between cytological and frozen section diagnosis, as well as between frozen section and routine paraffin embedded tissue diagnosis

Glioblastoma- cytology, Frozen section and permanent section

Awelimobor, 2011

Pituitary adenoma- cytology and frozen sectionAwelimobor, 2011

Meningioma- cytology, Frozen section and permanent section

Awelimobor, 2011

COMPARISON OF SELECTED AFRICAN SERIESTUMOUR TYPES

Ibadan 1957-1969N = 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 1956-1962N = 315*

Astro 15 (12.9) 53 (25.3%) 88 (24.7%) 21 (19.1%) 64 (34.2%) 33 (34%) 99 (31.4%)

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)

Germ cell 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)

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.

LIST OF REFERENCES

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