Related Experiment Video
Updated: Mar 28, 2026
A Syngeneic Orthotopic Osteosarcoma Sprague Dawley Rat Model with Amputation to Control Metastasis Rate
Published on: May 3, 2021
CIC-rearranged Sarcomas: A Study of 20 Cases and Comparisons With Ewing Sarcomas
Akihiko Yoshida1, Keisuke Goto, Makoto Kodaira
1Departments of *Pathology and Clinical Laboratories §Medical Oncology ∥Musculoskeletal Oncology ¶Pediatric Oncology #Head and Neck Oncology †Rare Cancer Center, National Cancer Center Hospital §§Department of Pathology, Tokyo Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo Departments of ‡Diagnostic Pathology **Neurosurgery, Kainan Hospital, Aichi Departments of ††Orthopedic Surgery ‡‡Clinical Laboratory Medicine and Diagnostic Pathology, Shiga University of Medical Science, Shiga, Japan.
Abstract:
The CIC gene rearrangement exists in a subset of small round cell sarcomas. As the nosologic relationship of these sarcomas to Ewing sarcomas remains undetermined, we examined 20 CIC-rearranged sarcomas to compare their clinicopathologic features with those of Ewing sarcomas. The CIC-rearranged sarcomas were from a group of 14 men and 6 women with a median age of 24.5 years. The primary tumor sites included the limbs, trunk wall, internal trunk, lung, cerebrum, and pharynx. A comparison of the demographic and clinical characteristics of the 20 patients with CIC-rearranged sarcomas with those of the 53 near-consecutive patients with EWSR1-rarranged Ewing sarcomas showed that there were no differences with respect to their ages and sexes. Although none of the CIC-rearranged sarcomas arose in the bone, 40% of the Ewing sarcomas primarily affected the skeleton. The overall survival of patients with Ewing sarcomas was significantly better than that for patients with CIC-rearranged sarcomas. A histologic comparison of the CIC-rearranged sarcomas with 20 EWSR1-rearranged Ewing sarcomas showed significantly higher degrees of lobulation, nuclear pleomorphism, the prominence of the nucleoli, spindle cell elements, and myxoid changes in the CIC-rearranged sarcomas. Distinguishing immunohistochemical features included heterogenous CD99 reactivity, nuclear WT1 expression, and calretinin expression in the CIC-rearranged sarcomas and NKX2.2 expression in the Ewing sarcomas. CIC-rearranged sarcomas are distinct from Ewing sarcomas clinically, morphologically, and immunohistochemically, and they should be considered a separate entity rather than being grouped within the same family of tumors.
Insights
CIC-rearranged sarcomas are distinct from Ewing sarcomas. These small round cell tumors differ in clinical presentation, histology, and immunohistochemistry, warranting separate classification.
Area of Science:
- Oncology
- Pathology
- Genetics
Background:
- CIC gene rearrangements are found in some small round cell sarcomas.
- The relationship between CIC-rearranged sarcomas and Ewing sarcomas is unclear.
Purpose of the Study:
- To compare clinicopathologic features of CIC-rearranged sarcomas with Ewing sarcomas.
- To determine if CIC-rearranged sarcomas represent a distinct entity.
Main Methods:
- Clinicopathologic analysis of 20 CIC-rearranged sarcomas.
- Comparison with 53 EWSR1-rearranged Ewing sarcomas.
- Histologic and immunohistochemical evaluation.
Main Results:
- CIC-rearranged sarcomas and Ewing sarcomas show similar demographics but differ in primary tumor sites (bone involvement in Ewing sarcomas).
- CIC-rearranged sarcomas have poorer overall survival compared to Ewing sarcomas.
- Histologic differences include lobulation, nuclear pleomorphism, and myxoid changes in CIC-rearranged sarcomas.
- Immunohistochemical markers like WT1 and calretinin are characteristic of CIC-rearranged sarcomas, while NKX2.2 is seen in Ewing sarcomas.
Conclusions:
- CIC-rearranged sarcomas are clinically, morphologically, and immunohistochemically distinct from Ewing sarcomas.
- CIC-rearranged sarcomas should be classified as a separate tumor entity.
