- Visibility 385 Views
- Downloads 339 Downloads
- Permissions
- DOI 10.18231/j.jdpo.2025.019
-
CrossMark
Small cell osteosarcoma morphological overlap with Ewings sarcoma: A case report
- Author Details:
-
Sangeetha Sundaram *
-
Reshma Pagidyala
-
Ashwini HN
Sangeetha Sundaram *
Reshma Pagidyala
Ashwini HN
Background: Small cell osteosarcoma is an uncommon, aggressive subtype of conventional osteosarcoma characterized by small round cell morphology. Due to its histological overlap with Ewing sarcoma, accurate diagnosis remains challenging but is crucial for determining appropriate treatment and prognosis.
Case Presentation: A 22-year-old male presented with left knee pain and swelling following trauma. Imaging revealed irregular trabecular and cortical features in the distal femur. Biopsy showed sheets of small, round tumor cells with hyperchromatic nuclei, high mitotic activity, and osteoid deposition in a lacy pattern. Given the morphological resemblance to Ewing sarcoma, immunohistochemistry was performed. The tumor cells showed strong nuclear positivity for SATB2, confirming the diagnosis of small cell osteosarcoma.
Conclusion: This case highlights the diagnostic challenges posed by small cell osteosarcoma due to its histologic similarity to Ewing sarcoma. It emphasizes the pivotal role of SATB2 immunostaining in distinguishing between these entities and underscores the need for an integrated diagnostic approach that combines clinical, radiological, histological, and immunohistochemical data
Keywords: Small cell osteosarcoma, Ewing sarcoma, SATB2.
References
- Fletcher CDM, Bridge JA, Hogendoorn P, Mertens F, editors. WHO classification of tumours of soft tissue and bone. 4th ed. Lyon: IARC Press; 2013
- Machado I, Navarro S, Picci P, Llombart-Bosch A. The Utility of SATB2 Immunohistochemical Expression in Distinguishing between Osteosarcomas and Their Malignant Bone Tumor Mimickers, such as Ewing Sarcomas and Chondrosarcomas. Pathol Res Pract. 2016;212(9):811–6.
- Hiemcke-Jiwa LS, Sumathi VP, Baumhoer D, Smetsers SE, Haveman LM, van Noesel MM, et al. Small Cell Osteosarcoma versus Fusion-Driven Round Cell Sarcomas of Bone: Retrospective Clinical, Radiological, Pathological, and (Epi)Genetic Comparison with Clinical Implications. Virchows Arch. 2024;484(3):451–63.
- Lichtenstein L, Bernstein D. Unusual benign and malignant chondroid tumors of bone: A survey of some mesenchymal cartilage tumors and malignant chondroblastic tumors, including a few multicentric ones, as well as many atypical ben ign chondroblastomas and chondromyxoid fibromas. Cancer. 1959;12(6):1142–57
- Ozdemirli M, Fanburg-Smith JC, Hartmann DP, Miettinen M. Primary lymphoma of bone: a clinicopathologic and immunophenotypic study of 8 cases. Mod Pathol. 2000;13(8):900–
- 86 Sundaram et al / IP Journal of Diagnostic Pathology and Oncology 2025;10(2):82-86
- Gerstle JT, Srinivasan R, Al-Ibraheemi A. Desmoplastic small round cell tumor: an overview. Pediatr Dev Pathol. 2013;16(6):411-416.
- Righi A, Gambarotti M, Longo S, Benini S, Gamberi G, Cocchi S, et al. Small Cell Osteosarcoma: Clinicopathologic, Immunohistochemical, and Molecular Analysis of 36 Cases. Am J Surg Pathol. 2015;39(5):691–9.
- Dehner, C. A.; Lazar, A. J.; Chrisinger, J. S. A. Updates on WHO Classification for Small Round Cell Tumors: Ewing Sarcoma vs. Everything Else. Hum Pathol. 2024;147:101–13.