Learning objectives
To make a brief review about the development of the spine.
To explain the anatomy of the sacrum.
To radiologically illustrate the most common sacral neoplasms: metastatic disease and primary bone tumor.
Background
Embryology:
Human spine development commences during embryogenesis and lasts until the age of thirty.
It occurs in four overlapping stages:
1.
Mesenchymal stage: The notochord forms in the 3rd gestational week and its role is to induce ectodermal and mesodermal differentiation resulting in formation of the neural plate,
which folds to form the neural tube.
It determines the spinal axis and contributes to the formation of the nucleus pulposus of the intervertebral disks.
Notochord cell remnants have been described in the cranial and caudal portions...
Imaging findings OR Procedure Details
BENIGN
Giant Cell Tumor: Fig. 1 Fig. 2 Fig. 3 Fig. 4
Only 3–7% of all giant cell tumors occur in spine; most of them in the sacrum.
Second most common primary tumor of the sacrum.
Women predominance (2:1).
Ages between 15 and 40 years.
Pain and neurologic deficits are the most common symptoms.
Composed of osteoclastic giant cells.
Locally aggressive.
Matrix calcifications and septations are absent.
Hemorrhagic and fibrotic areas are commonly found.
Spontaneous malignant transformation has been reported in fewer than 2% of...
Conclusion
The sacrum,
is optimally imaged with cross-sectional techniques.
The embriological development of the sacrum reflects some of the neoplastic lesions.
There are primary tumors,
particularly teratoma,
chordoma,
giant cell tumor,
and chondrosarcoma that have a predisposition for affecting the sacrum.
However metastatic disease is the most common sacral neoplasm.
Familiarity with all the tumors affecting the sacrum will enhance the possibility of arriving at a specific diagnosis,
appropriate differential diagnosis or management.
References
Primary Tumors of the Sacrum:Diagnostic Imaging.AJR2000;174:417–424 0361–803X/00/1742–417 © American Roentgen Ray Society
Diagnostic Imaging of Solitary Tumor of the Spine: What to Do and Say.RadioGraphics 2008; 28:1019–1041 • Published online 10.1148/rg.284075156.
The Sacrum: Pathologis Spectrum,
Multimodalit Imaging,
an Subspecialty Approach.RadioGraphics 2001; 21:83–104
The Sacrum: Pathologic Spectrum,
Multimodality Imaging,
and Subspecialty Approach.
RadioGraphics 2001; 21:83–104
Benign notochordal cell tumour: Case report.
http://dx.doi.org/10.1016/j.diii.2013.01.008