Related Experiment Video
Updated: Jul 13, 2026
08:57
Identifying, Diagnosing, and Grading Malignant Peripheral Nerve Sheath Tumors in Genetically Engineered Mouse Models
Published on: May 17, 2024
Diffuse-type giant cell tumor/pigmented villonodular synovitis arising in the sacrum: malignant form
Yoshinao Oda1, Tomonari Takahira, Ryohei Yokoyama
1Department of Anatomic Pathology, Graduate School of Medical Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan. surgpath.med.kyushi-u.ac.jp
Pathology International
|August 10, 2007
Summary
Diffuse-type giant cell tumor (GCT)/pigmented villonodular synovitis (PVNS) is rare in the spine. This case presents the first instance of malignant GCT/PVNS in the spine, highlighting the need for careful surveillance of these tumors at unusual sites.
Area of Science:
- Orthopedic Oncology
- Skeletal Pathology
- Tumor Recurrence Studies
Background:
- Diffuse-type giant cell tumor (GCT), also known as pigmented villonodular synovitis (PVNS), is an uncommon neoplastic proliferation of joints.
- GCT/PVNS typically affects appendicular joints, with axial skeleton involvement being exceptionally rare.
Observation:
- A case of diffuse-type GCT/PVNS involving the sacrum and fifth lumbar vertebra is presented.
- The patient experienced recurrence with regional lymph node swelling.
- Histological examination of the recurrent tumor revealed atypical features, including spindle cell morphology, cytological atypia, and a high mitotic rate.
Findings:
- The observed atypical histological features meet the criteria for secondary malignant diffuse-type GCT/PVNS.
- Although nodal lesions were not biopsied, clinical and histological data strongly suggest malignant transformation.
- This represents the first reported case of malignant diffuse-type GCT/PVNS originating in the spine or axial skeleton.
Implications:
- This case underscores the potential for GCT/PVNS to undergo malignant transformation, even at rare spinal locations.
- It highlights the importance of vigilant surveillance for diffuse-type GCT/PVNS, particularly when it occurs in unusual sites like the axial skeleton.
- Further research into the behavior and management of spinal GCT/PVNS is warranted.
