Case Study 6
Harry Kellermier, M.D.
Question 1
Describe this T1 weighted MRI and give a radiologic
differential.
Answer
Destructive lesion involving the clivus. The radiologic
differential includes chordoma, chondrosarcoma, and less
likely metastasis.
Question 2
Describe the microscopic findings.
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Answer
This neoplasm is composed of hepatoid trabeculae of
epithelioid cells with eosinophilic and bubbly cytoplasm in
a myxoid matrix. Some areas appear somewhat
chondroid.
Question 3
What is your histologic differential diagnosis?
Answer
Chordoma, Chondrosarcoma, Adenocarcinoma
Question 4
What immunostains would you order?
Answer
Keratins (AE1/AE3, Cam 5.2, or Pankeratin), S100, EMA,
CEA
Question 5
Based on the following immunohistochemical results,
what is your diagnosis?
AE1/AE3
CAM5.2
PANKERATIN
EMA
S100
Answer
1. Chordoma - Keratin positive, EMA positive, S100
positive, CEA negative
2. Chondrosarcoma would be S100 positive, keratin
negative, EMA negative; Adenocarcinoma would be
Keratin positive, EMA positive, CEA positive, and
usually S100 negative.
Question 6
What are the "bubbly" cells called in this tumor?
Answer
Physaliphorous cells (Greek - bubble bearing)
Question 7
From what developmental structure does this tumor
arise?
Answer
The notochord
Question 8
What anatomic locations do they typically involve?
Answer
Chordomas involve the midline of the axial
skeleton. 30%-40% involve the base of the skull (clivus in
the region of the spheno-occipital synchondrosis),
approximately 49% involve the sacrum, and
approximately 15% involve the vertebral column, usually
the cervical spine.
Question 9
What is the name of the benign developmental remnant of
notochord that histologically resembles a chordoma?
Answer
Ecchordosis physaliphora. These lesions are small, wellcircumscribed gelatinous masses adherent to the
brainstem. They behave in a benign manner.
Question 10
How do chordomas clinically behave?
Answer
Although they grow slowly, chordomas are characterized
by local destruction and multiple recurrences. Complete
surgical resection may be curative, but is extremely
difficult to attain. Radiation therapy may improve survival.
Question 11
Name 2 other chordoid neoplasms of the CNS.
Answer
Chordoid glioma of the third ventricle and Chordoid
meningioma.