# A Case Report of a 17 cm Retropharyngeal Well-Differentiated Liposarcoma With Bilateral Neck Extension

## TL;DR

This case report describes a rare 17 cm retropharyngeal liposarcoma in an elderly man, highlighting diagnostic challenges and the importance of MDM2 FISH analysis for confirmation.

## Contribution

The novelty lies in presenting a rare retropharyngeal well-differentiated liposarcoma case with bilateral neck extension and emphasizing MDM2 FISH analysis for diagnosis.

## Key findings

- MDM2 FISH analysis confirmed MDM2 gene amplification in a retropharyngeal liposarcoma.
- A 17 cm tumor was successfully resected via a hockey stick incision with no vocal cord damage.
- Retropharyngeal liposarcomas are rare and often misdiagnosed as benign lesions.

## Abstract

Liposarcomas, malignant adipocytic tumors, primarily manifest in the lower extremities and retroperitoneum, with a strikingly low incidence in the head and neck region. Symptomatology typically remains absent until the tumor attains significant size, leading to cosmetic concerns or compression-related complications. This report presents a unique case of well-differentiated retropharyngeal liposarcoma in an 81-year-old male, emphasizing diagnostic challenges, management strategies, and the crucial role of Mouse double minute 2 (MDM2) fluorescence in situ hybridization (FISH) analysis in confirmation.

The patient exhibited dysphagia attributed to a retropharyngeal mass, prompting suspicion of malignancy. Diagnostic assessments, including flexible laryngoscopy and percutaneous tru-cut biopsy, highlighted unique features such as atypical nuclear features in adipocytes. MDM2 FISH analysis definitively confirmed the diagnosis by detecting MDM2 gene amplification.

The rarity of retropharyngeal liposarcomas complicates diagnosis, often leading to confusion with benign lesions. Surgical excision, the mainstay of treatment, varies based on tumor size and extension. In this case, a left neck dissection via a hockey stick incision successfully resected a 17 cm well-differentiated liposarcoma. Pathologic analysis revealed focal involvement of resection margins, with no complications or vocal cord damage.

In conclusion, retropharyngeal liposarcomas pose diagnostic challenges, warranting reliance on MDM2 FISH analysis for accurate confirmation. Early surgical intervention, guided by tumor size and extension, is paramount for optimal outcomes in managing these rare tumors. This case underscores the significance of a detailed surgical approach in achieving successful outcomes for retropharyngeal liposarcomas.