What is the clinical evidence from this study?

Study design: Case Report. Population: Sinonasal synovial sarcoma (n=1). Intervention: Neoadjuvant chemotherapy.

May 31, 2026Open Access

Rare Presentation of Sinonasal Synovial Sarcoma With Frontal Sinus and Limited Intracranial Extension Associated With Probable Paraneoplastic Vasculitis: A Case Report

Key Result

Neoadjuvant chemotherapy led to the regression of vasculitic findings in a 38-year-old male with sinonasal synovial sarcoma, suggesting a probable paraneoplastic vasculitic association.

Key Points

This case aims to illustrate the rare presentation of sinonasal synovial sarcoma and its associated complexities.
Detailed neuroimaging was performed, including CT and MRI scans to assess the tumor and related complications.
Histopathological evaluations and immunohistochemical analysis confirmed the diagnosis of synovial sarcoma.
The patient received neoadjuvant chemotherapy followed by considerations for chemoradiotherapy and surgical intervention.
Histopathological evaluations confirmed a spindle-cell neoplasm consistent with synovial sarcoma.
Neoadjuvant chemotherapy resulted in regression of vasculitic findings, indicating a probable paraneoplastic association.
Planned treatment included combined chemoradiotherapy due to the complexity of the tumor's anatomical location.

Study Design

Type

Case Report (n=1)

Structured PICO

Population

38-year-old male with sinonasal synovial sarcoma and probable paraneoplastic vasculitis

Intervention

Neoadjuvant chemotherapy

Outcome

Regression of vasculitic findings

This case highlights a rare presentation of sinonasal synovial sarcoma associated with probable paraneoplastic vasculitis that regressed after neoadjuvant chemotherapy.

Abstract

Synovial sarcoma is a high‐grade soft‐tissue sarcoma that commonly affects adolescents and young adults. Involvement of the head and neck region is rare, and tumors arising from the sinonasal tract are particularly uncommon and diagnostically challenging. We report the case of a 38‐year‐old male who presented with head trauma and decreased consciousness following a transient neurological episode while driving. Brain computed tomography revealed a lesion involving the left anterior ethmoidal air cells with associated old cerebral infarctions. Further magnetic resonance imaging demonstrated an aggressive enhancing sinonasal mass with limited intracranial extension, associated with radiologic findings suggestive of vasculitis and acute‐on‐chronic ischemic insults. Histopathological evaluation showed a spindle‐cell neoplasm considered most consistent with synovial sarcoma based on morphology and available immunohistochemical findings. The patient was started on neoadjuvant chemotherapy, after which the vasculitic findings showed regression, suggesting a probable paraneoplastic vasculitic association. Due to the complex anatomical location and local extension of the tumor, complete surgical resection was not initially feasible. Planned management included combined chemoradiotherapy with consideration of future surgical intervention. This case highlights the diagnostic and therapeutic challenges of sinonasal synovial sarcoma and emphasizes the importance of multidisciplinary evaluation, particularly in cases associated with unusual vasculitic and ischemic manifestations.