Brain tumour excision and lobectomy

Background

Specimens from the excision or lobectomy of brain tumours are infrequently received in the laboratory.

Meningiomas are the most common extra-axial tumours but other histological types occur and should not be discounted in these specimens.1

The size of tumours and the extent of their resection are important prognostic factors for disease recurrence.2-5

See separate protocol for brain biopsies and pituitary specimens.


Record the patient identifying information and any clinical information supplied together with the specimen description as designated on the container. See overview page for more detail on identification principles.

Fresh tissue received
  • No
    • Non-routine fixation (not formalin), describe.
  • Yes
    • Special studies required, describe.
    • Ensure samples are taken prior to fixation.

Fresh unfixed tissue should be handled in appropriate extraction cabinets and with suitable personal protection equipment for infection control. Where sufficient material is available, unfixed specimens may be sampled for special studies using a fresh, sterile blade and distributed to appropriate laboratories (internal and external). These may include frozen sections, imprints, flow cytometry, microbiology, cytogenetics, molecular studies, tissue bank and electron microscopy. In some instances only a small amount of tissue may be submitted. In such cases, specimen triage is critical and discussion with the reporting Pathologist is advisable to optimise the diagnostic yield of the tissue available. 1,2

Electron microscopy is commonly required for pituitary specimens.1

Transfer majority of specimen to formalin and allow to fix for adequate period.

Intraoperative consultation
  • Not performed
  • Performed, describe type and result
    • Frozen section
    • Imprints
    • Other, describe

If a frozen section is requested the entire specimen must not be submitted (unless further tissue will be sent) for frozen section as freezing introduces significant artefact that may compromise diagnosis.

Follow best practice procedures to minimise cross-over contamination of small fragments to other specimens. 6

general information for more detail on specimen handling procedures.

Inspect the specimen and dictate a macroscopic description.

External InspectionBack to top


Orientate and identify the anatomical features of the specimen.

  • Lobectomy –orientate and identify anatomical structures.7
  • Extra-axial tumours, orientate and identify the brain interface if possible.7
Orientation markers

Orientation markers may be used for temporal lobe excisions when correct orientation is critical in ensuring that the hippocampus is sectioned in the correct plane.

Record additional orientation or designation provided by operating clinician:

  • Absent
  • Present
    • Method of designation (e.g. suture, incision)
    • Featured denoted

Photograph the intact specimen if required.

Describe the following features of the specimen:

Procedure

Record as stated by the clinican.

Options
  • Resection of lesion
    • Partial
    • Total macroscopic
    • Extent uncertain
  • Lobectomy
  • Other, describe

Anatomical components included (more than one may apply) and specimen dimensions (mm)

Describe and measure the anatomical components present. 

  • Intact specimens, measure in three dimensions 1,7
  • Large resection specimens, record weight (g) 1,7
  • Intra-axial tumour, describe components present
    • Cerebrum
    • Cerebellum
    • Brainstem
    • Spinal cord
  • Extra-axial tumour, describe components present
    • Intradural
    • Extradural
    • Skull
    • Paraspinal

Specimen integrity 1

  • Intact
  • Disrupted/fragmented

Photograph the intact specimen, if required.

DissectionBack to top


Specimens containing bone or large areas of calcification may require decalcification (after sufficient fixation) prior to dissection and processing. 1,7

Tumour resection specimens

After sufficient fixation, paint the relevant surgical margins with ink and record the colours applied.
Intact specimens should be transversely sectioned at 4-5 mm intervals (i.e. perpendicular to the long axis of the specimen and through the pial surface).1

Lobectomy specimens

Section at 5mm intervals, perpendicular to the cortical surface. 1,7

It is essential that hippocampal specimens from temporal lobe resections for the treatment of epilepsy are correctly orientated. It is critical that the hippocampus is sectioned in the correct plane to facilitate diagnosis of lesions such as hippocampal sclerosis.

If unable to orientate or if ambiguities exist, contact the on-call pathologist or surgeon.

After opening the specimen may require longer fixation in larger quantity of formalin. 

Internal InspectionBack to top


 Describe the cut surface appearance including the following items:

Tumour

  • Absent
  • Present
    • Number; if more than one tumour, designate and describe each tumour separately
    • Entire specimen consists of tumour

Tumour size (mm)

  • In three dimensions

Specimen description 7

  • Colour
  • Consistency
  • Haemorrhage
  • Necrosis
  • Cystic change
  • Calcification

Distance of tumour to margins

  • Where dura is included; distance of tumour to nearest radial dural  resection margin (mm) 7
  • Intra-axial tumours (including lobectomy specimens); note if tumour is:
    • Macroscopically apparent tumour at surgical resection margin 1
    • Macroscopically apparent tumour within leptomeninges  1

The assessment of margins is not critical intra-axial lesions.

Photograph the dissected specimen, if required.

Note photographs taken, diagrams recorded and markings used for identification.

ProcessingBack to top


Intra-axial tumour resections, including lobectomy specimens 1,7
  • Submit all fragments in their entirety if specimen < 10mm
  • Submit representative sections of larger specimens focussing on areas of possible haemorrhage and necrosis.
Extra-axial tumours 1,7
  • Submit one section per 10 mm of tumour including representative sections of adjoining brain, dura and radial margin (if present), focussing on areas of possible haemorrhage and necrosis. 1
  • For meningiomas, include sections from the junction with cortical tissue to enable reporting on the presence or absence of brain invasion i.e. breach of the pial barrier.1,8
Unprocessed tissue
  • If entire specimen is not processed, record amount of unprocessed tissue remaining (% or g) 7

Record details of each cassette.

An illustrated block key similar to the one provided may be useful.

Intra-axial tumour resections, including lobectomies1,7
Cassette id Site No. of pieces
A-C Brain tumour, representative sections including areas of possible haemorrhage and/or necrosis  
Extra-axial tumours 1,7
Cassette id Site No. of pieces
A-C Brain tumour  
D-E Brain tumour, possible areas of haemorrhage and/or necrosis  
Meningiomas 1,7
Cassette id Site No. of pieces
A-C Brain tumour  
D-E Brain tumour, possible areas of haemorrhage and/or necrosis  
F-G Brain tumour, representative sections from cortical tissue junction  

Acknowledgements

Dr Barbara Koszyca for her contribution in reviewing and editing this protocol.

ReferencesBack to top


  1. Wharton SB, Hilton D, Ironside JW, Grant R and Collins VP. Dataset for tumours of the central nervous system, including the pituitary gland, The Royal College of Pathologists, London, 2011.
  2. Timperley WR. ACP Best Practice No 158. Neuropathology. J Clin Pathol 2000;53(4):255-265.
  3. Berger MS, Deliganis AV, Dobbins J and Keles GE (1994). The effect of extent of resection on recurrence in patients with low grade cerebral hemisphere gliomas. Cancer 1994;74(6):1784-1791.
  4. Keles GE, Chang EF, Lamborn KR, Tihan T, Chang CJ, Chang SM et al. Volumetric extent of resection and residual contrast enhancement on initial surgery as predictors of outcome in adult patients with hemispheric anaplastic astrocytoma. J Neurosurg 2006;105:134-140.
  5. Pignatti F, van den Bent M, Curran D, Debruyne C, Sylvester R, Therasse P, Afra D, Cornu P, Bolla M, Vecht C and Karim AB. Prognostic factors for survival in adult patients with cerebral low-grade glioma. J Clin Oncol 2002;20(8):2076-2084.
  6. Lester SC. Extraneous Tissue. In: Manual of Surgical Pathology, Saunders Elsevier, Philadelphia, 2010;33-34
  7. Rodriguez M, Hovey E, Jeffree R, Koh E-S, Koszyca B, McKelvie P, McLean C, Robbins P and Robertson T. Central nervous system tumours structured reporting protocol, The Royal College of Pathologists of Australasia, Surry Hills, NSW, 2012.