TY - JOUR
T1 - Rare FUS::FEV–Rearranged Adamantinoma-Like Ewing Sarcoma Arising in the Submandibular Gland
AU - Agboola, Tomilola
AU - Miller, Daniel L.
N1 - Publisher Copyright:
© The Author(s) 2025.
PY - 2025/12
Y1 - 2025/12
N2 - Background: Adamantimoma-Like Ewing Sarcoma (ALES) is a rare variant of Ewing sarcoma that poses significant diagnostic challenges in the head and neck due to morphologic overlap with basaloid carcinomas and neuroendocrine neoplasms. Case Presentation: We report a case of a middle-aged man with a left submandibular gland mass showing classic histologic features of ALES, including basaloid nests with peripheral palisading, rosette formation, and high mitotic activity. Results: Immunohistochemistry showed co-expression of p63/p40, CD99, and cytokeratins, with patchy synaptophysin positivity and an elevated Ki-67 proliferation index. FISH for EWSR1 was negative, but next-generation sequencing identified a rare FUS::FEV fusion, previously reported only three times in ALES and never in the submandibular gland. Conclusion: This case highlights the importance of extended molecular testing when EWSR1 FISH is negative; as alternate FET::ETS fusions may underlie the diagnosis.
AB - Background: Adamantimoma-Like Ewing Sarcoma (ALES) is a rare variant of Ewing sarcoma that poses significant diagnostic challenges in the head and neck due to morphologic overlap with basaloid carcinomas and neuroendocrine neoplasms. Case Presentation: We report a case of a middle-aged man with a left submandibular gland mass showing classic histologic features of ALES, including basaloid nests with peripheral palisading, rosette formation, and high mitotic activity. Results: Immunohistochemistry showed co-expression of p63/p40, CD99, and cytokeratins, with patchy synaptophysin positivity and an elevated Ki-67 proliferation index. FISH for EWSR1 was negative, but next-generation sequencing identified a rare FUS::FEV fusion, previously reported only three times in ALES and never in the submandibular gland. Conclusion: This case highlights the importance of extended molecular testing when EWSR1 FISH is negative; as alternate FET::ETS fusions may underlie the diagnosis.
KW - Adamantinoma-Like Ewing Sarcoma
KW - FUS::FEV fusion
KW - Salivary gland malignant neoplasm
UR - https://www.scopus.com/pages/publications/105021200954
U2 - 10.1007/s12105-025-01857-0
DO - 10.1007/s12105-025-01857-0
M3 - Article
C2 - 41212431
AN - SCOPUS:105021200954
SN - 1936-055X
VL - 19
JO - Head and Neck Pathology
JF - Head and Neck Pathology
IS - 1
M1 - 126
ER -