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Temporal lobectomies usually come in two or three parts:

1) temporal cortex,
2) hippocampus, and
3) amygdala (optional)

Not always in that order. The temporal cortex is usually marked with a stitch in the anterior pole.

The specimen is handled in various ways depending on the clinical and radiological features (see #1, 2 and 3 below).

The specimens should be handled as little as possible prior to fixation and should be allowed to fix AT LEAST 48 hours prior to cutting.

NOTE: At Childrens, please request that these specimens be processed using the “autopsy” protocol in Histology (Lori Schmidt 412-692-6856 or email Lori.Schmitt@chp.edu)

TAKE IMAGES OF EACH PIECE PRIOR TO CUTTING.

1) CASES WITH CLEAR TUMOR BY NEUROIMAGING AND HISTORY

  • Put in representative sections of the tumor area and surrounding brain.
  • Orient hippocampus so that sections are taken in a coronal plane.
  • If uncertain how to do this, seek advice.

2) CASES WITH CLEAR HIPPOCAMPAL SCLEROSIS BY IMAGING AND HISTORY

  • Put in 3 representative section of the cortex (anterior, middle and posterior)
  • Orient hippocampus so that sections are taken in a coronal plane.
  • If uncertain how to do this, seek advice! The orientation is CRITICAL to the final evaluation of the case.

3) CASES WITHOUT OBVIOUS CAUSE OF SEIZURES

These are often cases in which the focus of seizure initiation has been localized using intracranial grid placement.

THE SEARCH IN THESE CASES IS FOR CORTICAL DYSPLASIA IN THE TEMPORAL LOBE CORTEX AND REQUIRES NUMEROUS WELL-FIXED SECTIONS TO EVALUATE.

SERIALLY SECTION FROM ANTERIOR TO POSTERIOR 2-3 MM INTERVALS THE ENTIRE TEMPORAL CORTEX.

PLACE EVERY OTHER SECTION IN A CASSETTE IN ORDER.

Orient hippocampus so that sections are taken in a coronal plane.

If uncertain how to do this, seek advice! The orientation is CRITICAL to the final evaluation of the case.

In all three cases, it is difficult if not impossible to orient the “amygdala” fragments. Place all in a cassette or two and submit.

Fig 1A – The smooth white surface in the lower right of the specimen is the inferior wall of the ventricle (beneath which is the alveus, the white matter track overlying the hippocampus). The irregular, jagged edge running diagnonally up the middle of the specimen (see the dotted yellow/black line in Fig 1B) is the cut surface of the white matter over the superior surface of the ventricle. The rounded smooth surface is the “key” to the hippocampus – in order to make a section so that the CA-1 region is easily identified, cut sections parallel to the ones shown in Fig 1B.

Fig 1B

Fig 1C – The lateral temporal lobe should always be oriented so the sections will be submitted anterior to posterior. Make multiple parallel cuts (Take photos before and after cuts if time). In cases of tumor, submit as needed. In cases of cortical dysplasia, it is best to submit all cut sections. In cases of mesial temporal sclerosis, where no cortical dysplasia is suspected, submit 3-4 representative sections.

Microscopic Grading