# Thoracic Spinal Sclerosing Epithelioid Fibrosarcoma Mimicking Schwannoma: Case Report and Literature Review

## TL;DR

A rare spinal tumor was mistaken for a schwannoma, highlighting the need for accurate diagnosis and multidisciplinary treatment.

## Contribution

This case report highlights the diagnostic challenges and management of a rare sclerosing epithelioid fibrosarcoma in the thoracic spine.

## Key findings

- The tumor was initially misdiagnosed as a schwannoma but was later identified as sclerosing epithelioid fibrosarcoma.
- The patient experienced recurrence despite initial surgery and chemotherapy, requiring further treatment with proton therapy.
- Literature review confirms the rarity of spinal SEF and the lack of standardized treatment protocols.

## Abstract

In this report, we describe the case of a young woman diagnosed with a thoracic foraminal lesion, initially suspected to be a common schwannoma. Following surgical resection, the lesion was identified as a rare malignant tumor, sclerosing epithelioid fibrosarcoma. The patient subsequently developed a recurrence, which required a second surgery and adjuvant proton therapy. By presenting this case alongside a review of previously published reports, our study underscores how this rare neoplasm can closely mimic more common spinal tumors, resulting in diagnostic delays or misclassification. We further highlight the need for a multidisciplinary management strategy and long-term surveillance. The insights gained from this work may assist spine surgeons in refining diagnostic accuracy and therapeutic decision-making for similarly rare spinal tumors.

Background/Objectives: Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue sarcoma with high rates of local recurrence and distant metastasis. Primary spinal involvement is exceedingly uncommon and often misdiagnosed due to radiological and histopathological resemblance to more frequent spinal tumors. The objective of this study is to present a rare case of thoracic spinal SEF and to contextualize it within the available literature. Methods: We describe the case of a 37-year-old woman presenting with progressive back pain and dysesthesia. MRI demonstrated a heterogeneously enhancing mass at the left T10–T11 neural foramen, initially interpreted as a common nerve sheath tumor. Gross total resection (GTR) was achieved, and histopathological analysis revealed a SEF. Clinical course, adjuvant therapies, and outcomes were evaluated, together with a review of previously reported spinal SEF cases. Results: Despite GTR followed by adjuvant chemotherapy, local recurrence occurred 18 months later. The patient underwent subtotal resection (STR) with adjuvant proton therapy. At 18-month follow-up after the second procedure, she remained neurologically stable and disease-free. The literature review confirmed the rarity of spinal SEF, its frequent misdiagnosis, and the absence of standardized therapeutic protocols. Conclusions: Spinal SEF is a rare malignancy that can mimic benign spinal tumors, delaying diagnosis. Its management relies on multidisciplinary assessment, individualized therapy, and long-term follow-up. This report increases awareness of spinal SEF and provides additional evidence to support clinical decision-making in rare spinal tumors.