Myeloid sarcomas with CBFA2T3 : GLIS2 fusion: clinicopathologic characterization of 4 cases mimicking small round cell tumors

• Published in: American journal of clinical pathology Vol. 163; no. 3; pp. 377 - 387
• Main Authors: Malik, Faizan, Eldomery, Mohammad K, Wang, Wei, Gheorghe, Gabriela, Khanlari, Mahsa
• Format: Journal Article
• Language: English
• Published: England 08.03.2025
• Subjects: Child, Preschool; Diagnosis, Differential; Female; Humans; Infant; Leukemia, Myeloid, Acute - diagnosis; Leukemia, Myeloid, Acute - genetics; Leukemia, Myeloid, Acute - pathology; Male; Oncogene Proteins, Fusion - genetics; Sarcoma, Myeloid - diagnosis; Sarcoma, Myeloid - genetics; Sarcoma, Myeloid - pathology; Sarcoma, Small Cell - diagnosis; Sarcoma, Small Cell - genetics; Sarcoma, Small Cell - pathology; acute myeloid leukemia; myeloid sarcoma; GLIS2
• ISSN: 0002-9173; 1943-7722; 1943-7722
• DOI: 10.1093/ajcp/aqae131

Acute myeloid leukemia with CBFA2T3::GLIS2 fusion can initially present as extramedullary lesions (myeloid sarcoma), leading to a misdiagnosis of nonhematologic pediatric solid tumors. We characterized the clinicopathologic features of 4 cases of CBFA2T3::GLIS2 fusion-positive myeloid sarcoma in pediatric patients where the sarcoma presented either without leukemic involvement (isolated myeloid sarcoma; 3/4 [75%]) or had concurrent leukemic disease (1/4 [25%]). All cases mimicked nonhematopoietic tumors at morphologic and immunophenotypic levels, so the initial evaluation did not raise suspicion for acute myeloid leukemia/myeloid sarcoma. After extensive workup, however, including molecular studies, the diagnosis of myeloid sarcoma with CBFA2T3::GLIS2 fusion was rendered. This study highlights the need for a high suspicion index of GLIS2-rearranged myeloid sarcoma in the differential diagnosis of pediatric small round cell tumors in tissue biopsies and the application of adequate workup to avoid misdiagnosing this entity.