Accuracy of grading gliomas on CT-guided stereotactic biopsies: a survival analysis

Venture in 101 Cranial Punctures: A Comparative Study between Frame-based versus Frameless Biopsy of 101 Intracranial Space Occupying Lesion

Background:

Presumptive diagnosis based solely on the clinical picture and imaging is not sufficient to provide appropriate treatment with certainty and hence histopathological confirmation of intracranial space occupying lesion (ICSOL) is essential. Needle biopsy via stereotactic frame-based or frameless neuronavigation technique is efficient procedure. The objective of this study is to compare their accuracy and efficacy and safety.

Methods:

This is a retrospective comparative study conducted among 101 biopsies of ICSOL. Patients data were retrieved from medical record. Data were analyzed in SPSS ver. 20. P value of <0.05 was considered significant.

Results:

Out of 101 patients, Frame-based stereotactic biopsy was done among 55 patients (54.4%) while 46 patients (45.6%) underwent frameless stealth neuronavigation guided biopsy. Male to female ration was 2.1:1. Age ranged from 5 to 82 years. 54.5% (55 patients) have deeper location of tumor while 45.5% (46 patients) have lobar location of tumor. Frontal (16.8%) and Thalamic (13.8%) were the common site. Mean size of tumor was 3.09±0.85cms. There was statistically significant difference in operative duration among study groups. Overall Diagnostic yield was 89.1%. Glioma was the most common (50.5%) diagnosis. Glioblastoma WHO Grade IV was 37.6% followed by lymphoma (12.8%).

Conclusion:

Needle biopsy via stereotactic frame-based or neuronavigation frameless technique is a safe and efficient procedure having high diagnostic yield. Reasons for negative biopsy could be missed target or retrieval of gliotic tissue.

The role of neuropathology in the management of patients with diffuse low grade glioma: A systematic review and evidence-based clinical practice guideline

TARGET POPULATION

Adult patients (age ≥18 years) who have suspected low-grade diffuse glioma.

QUESTION

What are the optimal neuropathological techniques to diagnose low-grade diffuse glioma in the adult?

RECOMMENDATION

LEVEL I: Histopathological analysis of a representative surgical sample of the lesion should be used to provide the diagnosis of low-grade diffuse glioma.

LEVEL III

Both frozen section and cytopathologic/smear evaluation should be used to aid the intra-operative assessment of low-grade diffuse glioma diagnosis. A resection specimen is preferred over a biopsy specimen, to minimize the potential for sampling error issues.

TARGET POPULATION

Patients with histologically-proven WHO grade II diffuse glioma.

QUESTION

In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is testing for IDH1 mutation (R132H and/or others) warranted? If so, is there a preferred method?

RECOMMENDATION

LEVEL II

IDH gene mutation assessment, via IDH1 R132H antibody and/or IDH1/2 mutation hotspot sequencing, is highly-specific for low-grade diffuse glioma, and is recommended as an additional test for classification and prognosis.

TARGET POPULATION

Patients with histologically-proven WHO grade II diffuse glioma.

QUESTION

In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is testing for 1p/19q loss warranted? If so, is there a preferred method?

RECOMMENDATION

LEVEL III

1p/19q loss-of-heterozygosity testing, by FISH, array-CGH or PCR, is recommended as an additional test in oligodendroglial cases for prognosis and potential treatment planning.

TARGET POPULATION

Patients with histologically-proven WHO grade II diffuse glioma.

QUESTION

In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is MGMT promoter methylation testing warranted? If so, is there a preferred method?

RECOMMENDATION

There is insufficient evidence to recommend methyl-guanine methyl-transferase (MGMT) promoter methylation testing as a routine for low-grade diffuse gliomas. It is recommended that patients be enrolled in properly designed clinical trials to assess the value of this and related markers for this target population.

TARGET POPULATION

Patients with histologically-proven WHO grade II diffuse glioma.

QUESTION

In adult patients (age ≥18 years) with histologically-proven WHO grade II diffuse glioma, is Ki-67/MIB1 immunohistochemistry warranted? If so, is there a preferred method to quantitate results?

RECOMMENDATION

LEVEL III

Ki67/MIB1 immunohistochemistry is recommended as an option for prognostic assessment.

Achieving Higher Diagnostic Results in Stereotactic Brain Biopsy by Simple and Novel Technique

BACKGROUND:

Neurosurgeons have preferred to perform the stereotactic biopsy for pathologic diagnosis when the intracranial pathology located eloquent areas and deep sites of the brain.

AIM:

To get a higher ratio of definite pathologic diagnosis during stereotactic biopsy and develop practical method.

MATERIAL AND METHODS:

We determined at least two different target points and two different trajectories to take brain biopsy during stereotactic biopsy. It is a different way from the conventional stereotactic biopsy method in which one point has been selected to take a biopsy. We separated our patients into two groups, group 1 (N=10), and group 2 (N= 19). We chose one target to take a biopsy in group 1, and two different targets and two different trajectories in group 2. In group 2, one patient underwent craniotomy due to hemorrhage at the site of the biopsy during tissue biting. However, none of the patients in both groups suffered any neurological complication related biopsy procedure.

RESULTS:

In group 1, two of 10 cases, and, in group 2, fourteen of 19 cases had positive biopsy harvesting. These results showed statistically significant difference between group 1 and group 2 (P<0.05).

CONCLUSIONS:

Regarding these results, choosing more than one trajectories and taking at least six specimens from each target provides higher diagnostic rate in stereotaxic biopsy taking method.

Sources of Error in Neuropathology Intraoperative Diagnosis

Objective:

The goal of this study was to optimize intraoperative neuropathology consultations by studying trends and sources of diagnostic error. We hypothesized that errors in intraoperative diagnoses would have sampling, technical, and interpretive sources. The study also audited diagnostic strengths, weaknesses and trends associated with increasing experience. We hypothesized that errors would decline and that the accuracy of “qualified” diagnoses would improve with experience.

Methods:

The pathologist's first 100 cases (P1), second 100 (P2), and most recent 100 (P3, after ten years in practice) formed the data set. Intraoperative diagnoses were scored as correct, minor error or major error using the final diagnosis as the gold-standard. Incorrect diagnoses were re-examined by two reviewers to identify sources of error.

Results:

Among the 300 cases there were 22 errors with 11 in P1, 9 in P2 and 2 in P3. Sampling contributed to 17 errors (77%), technical factors to 7 (32%) and interpretive factors to 16 (73%). Improvement in diagnostic accuracy between P1 and P2 (p=0.8143), or P2 and P3 (p=0.0582) did not reach significance. However, significant improvement was found between P1 and P3 (p=0.0184).

Conclusion:

The present study was a practical and informative audit for the pathologist and trainees. It reaffirmed the accuracy of intraoperative neuropathology diagnoses and informed our understanding of sources of error. Most errors were due to a combination of sampling, technical and interpretive factors. A significant improvement in diagnostic proficiency was observed with increasing experience.

Progression from on-site to point-of-care fine needle aspiration service: Opportunities and challenges

Background

Standard-of-care requires the availability of an efficient, economical and accurate on-site fine needle aspiration (FNA) service. Presence of a trained individual during the procedure ensures an improved patient care. Appropriate selection of the equipment, interaction with the clinicians and compliance with the various regulations during the procedure is essential. This is often done by an on-site FNA service. Organization and implementation of such a system in a large academic center is challenging.

Method

we reviewed the ambulatory care needs in the new Perelman Center for Advanced Medicine (PeCAM). Multiple (9) FNA sites have been established keeping in view the patient's convenience, clinic demands, various regulatory requirements and laboratory staff. Each location has dedicated FNA station with microscopes and supplies. In addition, state- ofthe -art technologies including a mobile FNA cart (Penn-A- Cart), remote specimen evaluation (TeleCyP) have been incorporated.

Results

The new set up is extremely efficient and much valued by the patients and the clinicians. It has improved patient care.

Conclusion

With necessary investments and resources a point-of-care FNA service has been created which has improved patient care. This, albeit with certain modifications may serve as a model for FNA service.

WT1 expression distinguishes astrocytic tumor cells from normal and reactive astrocytes

Particularly in small brain biopsies, it might be difficult to distinguish reactive astrogliosis from low-grade or infiltration zones of high-grade astrocytomas. So far no immunohistochemical marker allows a reliable distinction. Recently, the over-expression of Wilms' tumor gene product WT1 was reported in astrocytic tumor cells. However, no sufficient data on WT1 expression in normal or reactive astrocytes are available. Therefore, we investigated WT1 expression in paraffin-embedded brain sections from 28 controls, 48 cases with astrogliosis of various etiology and 219 astrocytomas [World Health Organization (WHO) grades I-IV] by immunohistochemistry. In normal brains and in astrogliosis, expression of WT1 was restricted to endothelial cells. In astrocytomas, WT1-positive tumor cells were found in pilocytic astrocytomas (66.7% of cases), diffuse astrocytomas (52.7%) WHO grade II (52.7%), anaplastic astrocytomas (83.4%) and glioblastomas (98.1%). Overall, the majority of all astrocytic neoplasms (84.5%) expressed WT1. Establishing a cut-off value of 0% immunoreactive tumor cells served to recognize neoplastic astrocytes with 100% specificity and 68% sensitivity and was associated with positive and negative predictive values of 1 and 0.68, respectively. Therefore, WT1 expression in astrocytes indicates a neoplastic origin and might represent an important diagnostic tool to differentiate reactive from neoplastic astrocytes by immunohistochemistry.

An analysis of stereotactic biopsy of brain tumors and nonneoplastic lesions: a prospective clinicopathologic study

BACKGROUND

Appropriate management of progressive, unverified brain lesions should be guided by conclusive pathological diagnosis. Stereotactic biopsy (SB) is established as a less invasive surgical procedure that provides diagnosis. In this prospective study, we analyzed the diagnostic difficulties and risk of SB in the various brain mass lesions, the rate of conclusive pathological diagnosis, and the rate of and the reasons for discrepancy between the intraoperative smear results and conclusive paraffin diagnosis.

METHODS

Using computed tomography (CT) and/or magnetic resonance imaging (MRI), 130 cases underwent SB procedure to assess intra-axial brain mass lesions. A CT-MRI fusion and a multiplanar image processing stereotactic program were used in cases who had lesions adjacent to the neurovascular and critical areas. The intraoperative evaluations were made with the smear preparations (SPs) of 1 or 2 biopsy specimens. The conclusive diagnosis was achieved by paraffin preparations of the remainder of the biopsies. The discrepancy between the smear results and the conclusive diagnosis was analyzed.

RESULTS

Conclusive histopathologic diagnosis was achieved in 99.23% of the cases. A discrepancy between smear results and conclusive diagnosis was detected in 6.98% of the conclusively diagnosed cases. The major reasons for the discrepancy were necrosis and improper quality of the preparations. There was no mortality, and hemorrhage-related morbidity was observed in 1 case (0.7%).

CONCLUSIONS

Necrosis and the improper quality of the smear preparations (SPs) can cause difficulties in establishing a histopathologic diagnosis in SB. Small tissue samples do not decrease the diagnostic yield with the new stereotactic technologies used by an experienced team consisting of a neurosurgeon, pathologist, and radiologist.

Clinical experiences with oligoastrocytomas WHO grade II and III

Between April 1991 and June 2002, 39 patients with an histologically proven oligoastrocytoma WHO grade II and III were operated on in our department. Twenty-two patients were male and 17 female. Mean age was 42 years (20-67 years). The tumor was localized in the frontal lobe in 22 patients, in the temporal lobe in seven patients, in the parietal lobe in nine patients and in the occipital lobe in one patient. The leading clinical symptoms were seizures in 33 patients. Seventeen patients were operated on under local anesthesia. One operation was performed in 22 patients, two operations in eight, three operations in five, four operations in three and six operations in one patient. Histological examination showed oligoastrocytoma WHO grade II in 12 patients and WHO grade III in 27 patients. Postoperative radiotherapy was performed in 33 patients and chemotherapy in six patients. One female patient developed spinal drop metastases 10 months after the operation. One patient with a primary oligoastrocytoma grade II and five patients with a primary oligoastrocytoma grade III died during follow-up. The follow-up period was between 6 months and 25 years (mean 7 years 6 months).

Stereotactic biopsy and cytological diagnosis of solid and cystic intracranial lesions

Cytological smears from 115 consecutive cases of stereotactic biopsies of intracranial lesions were reviewed. Ninety-five lesions were solid and 20 cystic. Material from 90 solid and 13 cystic lesions was sent both for cytological and histological examination. In 66 of the solid lesions, the cytological diagnosis was confirmed by histology (five were benign lesions and 61 malignant tumours: 56 primary brain tumours, three metastases and two lymphomas). In 24 cases with discrepant cytology and histology, the histology was inconclusive or insufficient in 14 cases, while cytology established the diagnosis of astrocytoma grade II (seven cases), metastases (two cases), gliosis (one case) and benign (four cases). Necrosis of tumour type was observed cytologically in six patients representing glioblastoma (two cases), anaplastic astrocytoma (one case), lymphoma (one case) and normal brain (two cases) histologically. Three cases reported cytologically as benign were primary brain tumour (two cases) and gliosis (one case). One smear of a glioblastoma was insufficient for cytological diagnosis. Cystic lesions were cytologically benign in 17 cases and malignant in three cases. Histology from the cyst wall confirmed the malignant diagnosis in three cases and showed tumour in six more cases, a benign process (two cases), changes induced by radiotherapy for arteriovenous malformation (one case) and insufficient material (one case). In conclusion, cytology from solid brain lesion allows an accurate diagnosis and subtyping of tumours in a majority of cases, and can thus be used to choose type of therapy. In cystic brain tumours, however, examination of the cystic fluid, is often inconclusive and a biopsy from the cyst wall should be performed if there is clinical or radiological suspicion of tumour.

Evaluation of rapid staining techniques for cytologic diagnosis of intracranial lesions

OBJECTIVE

To evaluate 4 rapid supravital stains and 3 preparation techniques for use in the intraoperative diagnosis of intracranial lesions.

ANIMALS

10 dogs and 1 cat euthanatized for intracranial lesions.

PROCEDURE

Specimens were taken from lesions and slides prepared, using 3 techniques: touch impression, medium-pressure impression, or smear preparation. Preparations were then stained with 4 stains: modified Wright stain, May-Grünwald-Giemsa, toluidine blue, and zynostain and examined in a blinded randomized fashion. Cytologic diagnosis was compared with histopathologic diagnosis and classified on the basis of identification of the pathologic process and specific diagnosis into the following categories: complete correlation, partial correlation, or no correlation.

RESULTS

An overall diagnostic accuracy of 81% (107/132) was achieved on the basis of a combination of partial and complete correlation. Of the stains examined, modified Wright stain appeared to be most accurate, with complete correlation in 17 of 33 (52%) specimens and partial correlation in 12 of 33 (36%) specimens. Of the preparation methods, touch preparation and smear preparation provided the most accurate results, with an overall diagnostic accuracy of 82% (36/44) for both methods. However, smear preparations appeared to be of greater diagnostic value, with fewer nondiagnostic specimens, compared with touch preparations.

CONCLUSIONS AND CLINICAL RELEVANCE

Cytologic preparations provide a useful diagnostic tool for the intraoperative diagnosis of intracranial lesions. All stains examined yielded promising results, the most accurate of which appeared to be the modified Wright stain. The smear preparation appeared to be the preparation method of greatest diagnostic value.

Differentiation between reactive gliosis and diffuse astrocytoma by in situ hybridization

The authors examined the use of chromosomal analysis by in situ hybridization to differentiate between nonneoplastic reactive gliosis and astrocytomas in cases in which routine histology was inconclusive. Numerical chromosomal aberrations were found in 80% of low-grade astrocytoma specimens and in none of the reactive gliosis specimens. Aneusomic tumor cells were detected in four of 13 stereotactic samples with an initially inconclusive tissue diagnosis, three of which were later diagnosed as astrocytoma. The in situ hybridization procedure may have additional value in the differential diagnosis of reactive gliosis versus low-grade astrocytoma.

ASTROCYTOMAS AND PROGNOSIS-FROM MORPHOLOGY TO TUMOR BIOLOGY

Twenty-seven cases of Astrocytoma were studied to assess the role of a newly introduced proliferation marker-Proliferating Cell Nuclear Antigen (PCNA) in improving prognostic accuracy in comparison to traditional histologic methods like grading. The study revealed a direct correlation between grading and PCNA expression as determined by labelling indices (LI). A 25% PCNA LI separated low and high grade tumors. The difference between PCNA LI's of patients who were alive and those who were dead at the end of the study was statistically significant. However, in this study with limited follow-up, statistically significant relation to survival and recurrence could not be established. The study introduces a new method of assessing tumor biology that enables objectivity in prediction of tumor behaviour.