Printer Friendly

IMAGING OF INTRACRANIAL TUMOURS WITH HISTOPATHOLOGICAL CORRELATION.

BACKGROUND

Brain tumour is a most dramatic form of illness of humankind. Imaging especially MRI plays a significant role not only in the diagnosis but also in the prognostication of the tumours.

Aside from the initial recognition and characterisation of these lesions (i.e., intra- vs. extra axial, neoplastic vs. nonneoplastic, pathologic type, benign vs. malignant, primary vs. metastatic, and grade of malignancy), the mechanical effects and structural deformities resulting from intracranial neoplasms are also of great importance because the cranium has extremely limited compliance to accommodate increased intracranial pressure.

Although MR imaging has delivered remarkable advances in the information available from the vast array of pulse sequences and MR imaging techniques, the radiologist should still rely most heavily on traditional, more fundamental criteria, such as location in the neuraxis and the age of the patient, for specific pathologic diagnoses.

Aims and Objectives

The present study was done to know the sensitivity and specificity of CT & MRI in diagnosis which is the gold standard for diagnosing intracranial tumours.

MATERIALS AND METHODS

This is a prospective study involving 50 patients with signs and symptoms of intracranial tumours who were admitted in the Department of Neurosurgery, Kurnool Medical College, Andhra Pradesh.

The study was done for a period of 2 years from October 2014 to October 2016.

Method of Collection of Data Inclusion Criteria

Patients with signs and symptoms of intracranial tumours between all the age groups are included.

Exclusion Criteria

Patients for whom CT or MRI could not be performed due to raised serum creatinine levels, pregnancy.

Patients for whom surgery or HPE was not done are excluded.

All the patients with suspected intracranial tumours underwent Plain and Contrast Computed tomography of Brain on 16 Slice G Bright Speed CT.

Plain and contrast MRI was done for all the patients on XGY 0.35 Tesla.

Histopathology examination was done postoperatively by using Haematoxylin & Eosin stain in the Department of Pathology, Kurnool Medical College. Number of Patients Included: 50.

Justification of Sample Size

All the patients with suspected clinical diagnosis of intracranial tumour from the period of 2 years from October 2014 to October 2016. A total of 50 patients were included.

Study Involves

Humans only.

Type of Study

Descriptive study.

Collected data was analysed by comparing it with histopathology to know sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of the imaging modalities.

RESULTS

In this prospective study involving 50 patients, 5 cases (10%) are below the age of 20 years, 18 cases (36%) are between the age group 20-40 years, and 27 cases (54%) are seen in patients of age above 40 years (Table 1).

Among 50 patients, 19 were male and 31 were female (Table 1).

Among 50 cases in the present study, Meningiomas accounted for 18 cases, followed by Astrocytomas accounting for 17 cases and Schwannoma and Tuberculomas with 3 cases each ,2 cases of Pituitary macroadenoma, 2 cases of Craniopharyngioma, one case of oligoastrocytoma, oligodendroglioma/Subependymoma, secondaries, medulloblastoma each (Table 2).

In present study of 50 patients, 38 patients have supratentorial distribution whereas remaining 12 have an infratentorial distribution (Table 2).

Out of 50 cases, 41 cases are correctly diagnosed on CT, 7 cases are incorrectly diagnosed (Table 4).

Out of 7 cases which are incorrectly diagnosed on CT, 5 cases are false positives and 2 cases are false negatives.

Out of the 50 cases, MRI has diagnosed 44 cases correctly and 4 cases have been diagnosed incorrectly on MRI (Table 5).

The Sensitivity, Specificity, Positive predictive value, Negative predictive value and p value of CT are 95.35%, 28.57%, 89.13%, and 50%, 0.03 (significant) respectively.

The Sensitivity, Specificity, Positive predictive value, Negative predictive value and p value of MRI are 97.78%, 40%, 93.16%, 66%, 0.0007 (Significant) respectively.

DISCUSSION

In the present study out of 50 cases, 5 cases (10%) are below the age of 20 years, 18 cases (36%) are between the age group 20-40 years, and 27 cases (54%) are seen in patients of age above 40 years.

According to Merchant TE et al, approximately 20,500 primary brain tumours are diagnosed in the United States each year, and of these, 3,750 (or 18.3%) occur in patients less than 19 years of age. [1]

According to Scott et al, 80% to 85% of all intracranial tumours occur in adults.

Among the patients aged below 20 years, there are 2 cases of craniopharyngioma, 1 case of Medulloblastoma, Tuberculoma, Ependymoma/Oligodendroglioma each.

Only 1% to 2% of all brain tumours occur in children under 2 years of age which include primitive neuroectodermal tumour, teratoma, astrocytoma and choroid plexus carcinoma.

Approximately, half of all intracranial neoplasms in children are gliomas; 15% are Primitive neuroectodermal tumours including medulloblastoma, ependymoma and craniopharyngioma account for about 10% each. [2, 3].

Embryonal/primitive neuroectodermal/medulloblastoma and pilocytic astrocytomas are the most common tumours before age 9 years, and gliomas grade I to III between 10 and 19 years are common. [4]

In patients aged between 20 and 40 years, Meningiomas accounted for 7 cases, Astrocytomas accounted for 6 cases, Schwannomas for 3 cases, Tuberculomas for 2 cases.

In patients aged above 40 years, Astrocytomas accounted for 12 cases, Meningiomas for 11 cases, Pituitary macroadenomas accounted for 2 cases, Central neurocytoma and secondaries accounted for 1 case each.

Approximately, 50% of the intracranial tumours are gliomas. Most of them (70%) are astrocytic tumours, and more than 50% of these are anaplastic or Glioblastoma Multiforme. [5]

Approximately, 15-20% of primary tumours in adults are meningiomas, most of them (75%) found supratentorially. [6]

Out of 50 cases, 41 cases are correctly diagnosed on CT, 7 cases are incorrectly diagnosed (Table 6).

Out of 7 cases which are incorrectly diagnosed on CT, 5 cases are false positives and 2 cases are false negatives.

The Sensitivity, Specificity, Positive predictive value, Negative predictive value and p value of CT are 95.35%, 28.57%, 89.13%, and 50%, 0.03 (significant) respectively.

According to a study done by Taghipour Zahir et al, [7] the Sensitivity, Specificity, Positive predictive value, Negative predictive value of CT for the diagnosis of CNS tumours was 83%, 10%, 93%, 3% respectively.

In the present study, the diagnosis was incorrectly made for five cases of gliomas, where two cases of Grade III Astrocytoma were wrongly diagnosed as cerebral abscess and Metastasis respectively, one case of Grade II astrocytoma was wrongly diagnosed as acute infarct, one case of Oligoastrocytoma was wrongly diagnosed as Meningioma, one case of GBM was wrongly diagnosed as Choroid plexus carcinoma.

In 1979, Kendall et al [8] highlighted the difficulties and pitfalls of diagnosing malignant gliomas on CT scan appearances alone.

They noted that of 314 patients with tumours of known histology, 12.7% were misdiagnosed, and in 6-5% a benign lesion was incorrectly reported as malignant. Baker et al [9] looked at the false-positive and false-negative rate in the interpretation of nearly 3,000 scans.

In their series, 13 out of 464 (2.8%) of non-neoplastic lesions were diagnosed as "neoplasms". In 80 of the 1071 (75%) neoplasms, the neuroradiologists failed to diagnose the histological type.

Out of the 50 cases, MRI has diagnosed 44 cases correctly and 4 cases have been diagnosed incorrectly on MRI (Table 8).

The Sensitivity, Specificity, Positive predictive value, Negative predictive value and p value of MRI are 97.78%, 40%, 93.16%, 66%, 0.0007 (significant) respectively.

CONCLUSION

Radiology has always been pivotal in the diagnosis and management of central nervous system (CNS) neoplasms. The main imaging modality of choice is MRI. The conventional MRI can help in arriving at diagnosis in most of the cases, but still advanced MR imaging modalities play a crucial role in certain situations such as grading of gliomas, differentiating a GBM from tuberculoma, high-grade glioma from cerebral abscess and vice versa and the differentiation is very important as the treatment provided greatly differs and from prognosis point of view also. For example, patient with metastasis needs a systemic imaging evaluation for the primary and also chemoradiotherapy.

Compared to CT, MRI has a better sensitivity, specificity, PPV, NPV and diagnostic accuracy.

The Limitations of Present Study include

1. Small study population.

2. Advanced imaging applications such as CT perfusion, MR spectroscopy have not been applied.

REFERENCES

[1] Merchant TE, Pollack IF, Loeffler JS. Brain tumors across the age spectrum: biology, therapy, and late effects. Semin Radiat Oncol 2010; 20(1):58-66.

[2] Harwood-Nash DC. Primary neoplasms of the central nervous system in children. Cancer 1991; 67(4 Suppl):1223-8.

[3] Buetow PC, Smirniotopoulos JG, Done S. Congenital brain tumors: a review of 45 cases. AJNR Am J Neuroradiol 1990; 11(4):793-9.

[4] Kaderali Z, Lamberti-Pasculli M, Rutka JT. The changing epidemiology of paediatric brain tumours: a review from the hospital for sick children. Childs Nerv Syst 2009; 25(7):787-93.

[5] Wemer MH, Phuphanich S, Lyman GH. The increasing incidence of malignant gliomas and primary central nervous system lymphomas in the elderly. Cancer 1995; 76(9):1634-42.

[6] DeMonte F, Al-Mefty 0. Meningiomas. In: Kaye AH, Laws ER. (eds). Brain tumors. New York, Churchill Livingstone, 1995:675-704.

[7] Taghipour Zahir SH, Sadrabadi MR, Dehghani F. Evaluation of diagnostic value of CT scan and MRI in brain tumors and comparison with biopsy. Iranian Journal of Pediatric Hematology Oncology 2011; 1(4):121-5.

[8] Kendall BE, Jakubowski J, Pullicino P, et al. Difficulties in the diagnosis of supratentorial gliomas by CAT scan. J Neurol Neurosurg Psychiatry 1979; 42(6):485-92.

[9] Baker HL, Houser OW, Campbell JK. National cancer institute study: evaluation of computed tomography in the diagnosis of intracranial neoplasms. I. Overall results. Radiology 1980; 136(1):91-6.

Jamkhana Abdul Gafoor (1), Onteddu Joji Reddy (2), Baila Suresh (3), D. Harinath (4), Bandi Arun Kumar (5)

(1) Professor, Department of Radiodiagnosis, Kurnool Medical College, Kurnool.

(2) Professor and HOD, Department of Radiodiagnosis, Kurnool Medical College, Kurnool.

(3) Associate Professor, Department of Radiodiagnosis, Kurnool Medical College, Kurnool.

(4) Assistant Professor, Department of Radiodiagnosis, Kurnool Medical College, Kurnool.

(5) Senior Resident, Department of Radiodiagnosis, Kurnool Medical College, Kurnool.

'Financial or Other Competing Interest': None.

Submission 23-08-2017, Peer Review 29-09-2017, Acceptance 05-10-2017, Published 12-10-2017.

Corresponding Author:

Dr. Jamkhana Abdul Gafoor, H. No. 49-1-73, Maddurnagar, Kurnool-518002, Andhra Pradesh, India.

E-mail: jamkhana@gmail.com

DOI: 10.14260/jemds/2017/1251
Table 1. Descriptive Statistics of Patient's Demography

Measure                  Number   Percentage

Minimum age 3
Maximum age 70
Mean age 40.3125+14.77

Sex
Male                       19         38
Female                     31         62

Age Groups (years)
<20                        5          10
20-40                      18         36
>40                        27         54

Table 2. Distribution of CNS Tumours According to
Histopathology

Tumour                            Number

Grade II astrocytoma                6
Grade III astrocytoma               5
Glioblastoma multiforme             6
Oligodendroglioma/Subependymoma     1
Meningioma                          18
Schwannoma                          3
Pituitary macroadenoma              2
Craniopharyngioma                   2
Medulloblastoma                     1
Central neurocytoma                 1
Tuberculoma                         3
Secondaries                         1
Oligoastrocytoma                    1

Table 3. Supratentorial and Infratentorial wise
Distribution of CNS Tumours

Compartment      Number

Supratentorial     38
Infratentorial     12

Table 4. Comparison of CT Diagnosis with
Histopathological Diagnosis

                          HPE

                 Positive   Negative

CT    Positive      41         5
      Negative      2          2

Table 5. Comparison of MRI Diagnosis with
Histopathological Diagnosis

                          HPE

                 Positive   Negative

MRI   Positive      44         3
      Negative      1          2

Table 6. List of False Positives and False Negatives on CT

CT Diagnosis               Histopathological Diagnosis

Metastasis                    Grade III Astrocytoma
Meningioma                      Oligoastrocytoma
Cerebral abscess              Grade III Astrocytoma
GBM                               Tuberculosis
Choroid plexus carcinoma        Craniopharyngioma
Choroid plexus carcinoma     Glioblastoma multiforme
Acute infarct                    Grade II glioma

Table 7. Comparison of CT in Present Study with Other
Studies

                            Present    Taghipour
                             Study    Zahir et al

Sensitivity                 95.35%        83%
Specificity                 28.57%        10%
Positive predictive value   89.13%        93%
Negative predictive value     50%         3%
Accuracy                      86%         78%

Table 8. False Positives and False Negatives on MRI

MRI diagnosis       Histopathological diagnosis

Metastasis             Grade III astrocytoma
High-grade glioma        Oligoastrocytoma
Tuberculosis          Glioblastoma multiforme
High-grade glioma          Tuberculosis

Table 9. Comparison of MRI in Present Study
with Other Studies

                            Present    Taghipour
                             Study    Zahir et al

Sensitivity                 97.78%        92%
Specificity                   40%         25%
Positive predictive value   93.16%        93%
Negative predictive value     66%         2%
Accuracy                      94%         87%
COPYRIGHT 2017 Akshantala Enterprises Private Limited
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2017 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:Original Research Article
Author:Gafoor, Jamkhana Abdul; Reddy, Onteddu Joji; Suresh, Baila; Harinath, D.; Kumar, Bandi Arun
Publication:Journal of Evolution of Medical and Dental Sciences
Article Type:Clinical report
Date:Oct 12, 2017
Words:2002
Previous Article:INDUCTION OF LABOUR WITH VAGINAL MISOPROSTOL IN INTRAUTERINE FOETAL DEATH.
Next Article:STUDY OF PREVALENCE OF GRANULOMATOUS LYMPHADENITIS IN INDIVIDUALS AFFECTED WITH HIV INFECTION.
Topics:

Terms of use | Privacy policy | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters