Diagnostic Work-Up in the Histological Verification of A Rare Solitary Fibrous Tumor

Solitary fibrous tumors are an extremely rare group of ubiquitous tumors of mesenchymal origin with an incidence of 1 per 1 million per year. The scarcity of published clinical cases describing their cytological findings and clinical features is the reason why the topic is of unique importance to both pathological and surgical studies. Originally thought to be exclusive to the pleural lining, it is now known that solitary fibrous tumors can occur anywhere in the body. In the past decade the diagnostic and therapeutic landscape of patients with verified solitary fibrous tumors has been refined. While fine-needle aspiration remains more accessible, the ultrasound- and computed tomography-guided biopsy paves the way to a narrower differential diagnosis. In the following case report, we present a case of a malignant solid fibrous tumor, located in the abdominal cavity, its clinical presentation, and the arduous diagnostic workup, which lead to its histological verification.