Benign notochordal cell tumours (BNCT) are vertebral lesions that are usually asymptomatic and discovered incidentally on imaging of the head or spine. As this is a poorly-recognised entity, it can often be confused with aggressive vertebral lesions, such as a chordoma, when it is seen on imaging.
Autopsy studies show BNCTs are extremely common with a reported incidence of up to 20% in cadaveric specimens 1. While only the larger of these lesions can be seen on imaging it is felt they are under-reported 2.
The vast majority of lesions are asymptomatic but a small proportion of patients can present with chronic back pain and coccydynia 2.
The distribution is similar to chordomas:
- clivus (50%)
- vertebral body sclerosis
- can extend to the cortex or involve the entire vertebra
- preserved trabeculae
- no cortical destruction
- well-defined osseous lesions
- T1: hypo- or isointense; may demonstrate hyperintense intra-lesional punctiform foci representing fat lobules due to entrapped bone marrow
- T2: hyperintense
- T1 C+ (Gd): usually no enhancement (in around 75% of cases)
- DWI: no restricted diffusion
- no soft tissue component
Often show no uptake on bone scintigraphy.
Treatment and prognosis
While there is a consensus that no specific treatment is required for asymptomatic lesions, the long-term malignant potential of BNCTs to transform into chordomas is not known and many advocate interval follow-ups 5.
- 1. Yamaguchi T, Suzuki S, Ishiiwa H, Shimizu K, Ueda Y. Benign notochordal cell tumors: A comparative histological study of benign notochordal cell tumors, classic chordomas, and notochordal vestiges of fetal intervertebral discs. (2004) The American journal of surgical pathology. 28 (6): 756-61. Pubmed
- 2. Amer HZ, Hameed M. Intraosseous benign notochordal cell tumor. (2010) Archives of pathology & laboratory medicine. 134 (2): 283-8. doi:10.1043/1543-2165-134.2.283 - Pubmed
- 3. Nishiguchi T, Mochizuki K, Ohsawa M, Inoue T, Kageyama K, Suzuki A, Takami T, Miki Y. Differentiating benign notochordal cell tumors from chordomas: radiographic features on MRI, CT, and tomography. (2011) AJR. American journal of roentgenology. 196 (3): 644-50. doi:10.2214/AJR.10.4460 - Pubmed
- 4. Nouh MR, Eid AF. Magnetic resonance imaging of the spinal marrow: Basic understanding of the normal marrow pattern and its variant. (2015) World journal of radiology. 7 (12): 448-58. doi:10.4329/wjr.v7.i12.448 - Pubmed
- 4. Yamaguchi T, Yamato M, Saotome K. First histologically confirmed case of a classic chordoma arising in a precursor benign notochordal lesion: differential diagnosis of benign and malignant notochordal lesions. (2002) Skeletal radiology. 31 (7): 413-8. doi:10.1007/s00256-002-0514-z - Pubmed
- 5. Kyriakos M. Benign notochordal lesions of the axial skeleton: a review and current appraisal. Skeletal Radiology. 40 (9): 1141. doi:10.1007/s00256-011-1167-6
- 6. Lalam R, Cassar-Pullicino VN, McClure, Singh J. Entrapped intralesional marrow: a hitherto undescribed imaging feature of benign notochordal cell tumour. (2012) Skeletal Radiology. 41 (6): 725. doi:10.1007/s00256-012-1371-z - Pubmed