An Unusual Case: Solitary Fibrous Tumor of the Lateral Abdominal Wall Muscles

Abstract

Background: Solitary fibrous tumor (SFT) is a mesenchymal tissue-based soft tissue tumor known for its potential aggressiveness. SFTs located in the abdominal wall are particularly rare. This report presents a unique case of SFT originating from the muscles of the abdominal wall.

Case Report: A 40-year-old male patient was referred to our hospital due to a mass in the left hypochondrium. Abdominal ultrasonography (US) revealed a heterogeneous, hypoechoic tumor with lobulated margins and limited blood supply. Magnetic resonance imaging (MRI) using Gadobutrol (Gadovist® 1.0, Schering AG, Berlin, Germany) demonstrated signal intensity heterogeneity and significant enhancement. The mass was excised en bloc. The specimen was immunopositive for Cluster of Differentiation 34 (CD34), Signal Transducer and Activator of Transcription 6 (STAT-6), desmin, and showed a 10.0% positivity for Ki-67. Follow-up examinations showed no evidence of tumor recurrence.

Conclusion: SFTs can display aggressive behavior as they often lack morphological indications of malignancy at the initial stages. For patients diagnosed with SFT, complete surgical excision is curative.