Biphenotypic Sinonasal Sarcoma with a Novel PAX7::PPARGC1 Fusion: Expanding the Spectrum of Gene Fusions Beyond the PAX3 Gene.
Head Neck Pathol
; 17(3): 826-831, 2023 Sep.
Article
in En
| MEDLINE
| ID: mdl-37378830
ABSTRACT
Biphenotypic sinonasal sarcoma (BSNS) is a rare low-grade malignancy occurring in the sinonasal tract that is characterized by dual neural and myogenic differentiation. Rearrangements involving the PAX3 gene, usually with MAML3, are a hallmark of this tumor type and their identification are useful for diagnosis. Rarely, a MAML3 rearrangement without associated PAX3 rearrangement has been described. Other gene fusions have not been previously reported. Herein, we report a 22 year-old woman with a BSNS harboring a novel gene fusion involving the PAX7 gene (specifically PAX7PPARGC1A), which is a paralogue of PAX3. The histologic features of the tumor were typical with two exceptions a lack of entrapment of surface respiratory mucosa and no hemangiopericytoma-like vasculature. Immunophenotypically, the tumor was notably negative for smooth muscle actin, which is usually positive in BSNS. However, the classic S100 protein-positive, SOX10-negative staining pattern was present. In addition, the tumor was positive for desmin and MyoD1 but negative for myogenin, a pattern that is common among BSNS with variant fusions. Awareness of the possibility of PAX7 gene fusions in BSNS is important as it may aid in the diagnosis of PAX3 fusion negative tumors.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sarcoma
/
Soft Tissue Neoplasms
/
Paranasal Sinus Neoplasms
Type of study:
Prognostic_studies
Limits:
Adult
/
Female
/
Humans
Language:
En
Journal:
Head Neck Pathol
Journal subject:
NEOPLASIAS
/
PATOLOGIA
Year:
2023
Type:
Article
Affiliation country:
United States