Am J Otolaryngol Head Neck Surg | Volume 8, Issue 1 | Case Report | Open Access
Department of Otolaryngology, Head and Neck Surgery Unit University Hospital of Ferrara, Italy
*Correspondance to: [email protected]
Fulltext PDFWe present a 50-year-old male with a diagnostically arising solitary fibrous tumor in the soft tissue of the neck. The tumor was well circumscribed and deeply localized in the neck adherent to the inferior oblique muscle of the head and the posterior big rectus muscle. Background: Solitary Fibrous Tumor (SFT) is a rare mesenchymal tumor, making up less than 2% of all soft tissue masses. While initially identified in the pleura, SFTs can develop anywhere in the body, including the head and neck region. Head and neck locations include the oral cavity, sinonasal region, neck soft tissues, thyroid, parotid gland, scalp, and larynx. Due to the low incidence of SFT, diagnostic strategies and treatment planning are challenging, as most data come from small retrospective series and case reports. SFTs have been linked to a NAB2-STAT6 gene fusion product, which is highly specific and sensitive for diagnosis. Pretreatment biopsy, ideally an open incisional biopsy or central needle biopsy, performed by an experienced professional, is crucial for diagnosis and classification. Tumor size varies significantly with location, with a median size between 7 cm – 10 cm. Grossly, these tumors are typically well-circumscribed with smooth surfaces, often lobular in shape. Distant metastasis is rare in reported SFT cases. This case report describes a solitary fibrous tumor located in the soft tissue of the neck in a 50-year-old male. Methods: A 50-year-old male presented with a painless mass on the right side of his neck. A Computed Tomography (CT) scan showed a well-defined, ovoid mass measuring 5.63×5.06 cm. The occipital artery and nerve were clearly separated and preserved during surgery. Magnetic resonance imaging (MRI) revealed a mass intimately related to the right inferior oblique muscle of the head, appearing T2 hyperintense and T1 isointense to the muscle, with no post-contrast enhancement. Numerous blood vessels were observed within the mass. Fine-needle aspiration cytology-biopsy confirmed a solitary fibrous tumor. The patient underwent surgery at Cona hospital (FE) by a multidisciplinary team of otolaryngologists, orthopaedists, and neurosurgeons. The surgery lasted two and a half hours, involving incisions of the skin, subcutaneous tissues, trapezius muscle, splenius capitis muscle of the neck, semifinal muscle of the head, and small rectus muscle of the head. Blunt dissection localized the neoformation, which was adherent to the inferior oblique muscle of the head and the posterior big rectus muscle. The occipital nerve and occipital artery were preserved. The neoformation was completely removed down to the posterior arch of the atlas and sent for pathological examination. The patient was re-evaluated at 3 and 5 weeks post-surgery. Results: The resected mass was a well-circumscribed, ovoid specimen measuring 7×6×5 cm, surrounded by fibro-adipose and skeletal muscle tissue. Macroscopically, the lesion was solid, whitish, and measured 4.4×3.8 cm. No necrosis or soft tissue invasion was identified. Microscopic examination revealed a well-circumscribed tumor composed of spindled to ovoidal cells with pale eosinophilic, scant cytoplasm, and indistinct cell borders. These cells were surrounded by abundant myxoid stroma mixed with branching and hyalinized staghorn-shaped blood vessels. Necrotic areas were absent, and mitotic figures were rare (equal to 1 per high power field). Based on these parameters, the patient’s age (50 years, i.e., <55 years), and the lesion size (i.e., <5 cm), the neoplasm was classified as low risk for recurrence and distant metastases according to the WHO 5th edition. Immunohistochemical analysis showed strong and widespread cytoplasmic positivity for CD34 and nuclear positivity for STAT6, supporting the SFT diagnosis. The growth fraction of neoplastic cells, evaluated with Ki67, was 2%. Post-surgical follow-up at 3 weeks showed a good surgical wound condition, with the patient reporting paraesthesia in the cervical region and scalp. Physio kinesis therapy was recommended. At 5 weeks post-surgery, the surgical wound remained good, but dysesthesia persisted in the cervical and scalp regions. The patient also reported a limitation in head torsion to the right, while other movements (flexion-extension and rotation) were preserved. The anatomy-pathological examination confirmed negative surgical margins. Given the low-risk classification per WHO guidelines, postoperative adjuvant radiotherapy was not implemented. Conclusion: We report the diagnosis, treatment, and 3- and 5-week post-radical surgery follow-up of a solitary fibrous tumor in the soft tissue of the neck in a 50-year-old male patient. The median age for SFT presentation is 51 years, and the median tumor size in the neck is 5 cm. While recurrence (distal or local) occurs in 10–30% of SFTs, with 10–40% of recurrences reported after 5 years, positive surgical resection margins are identified as a significant risk factor for local recurrence. In this case, complete surgical resection with negative margins was achieved, and no necrosis or soft tissue invasion was identified. The low mitotic rate (1 per 10 high power fields) further supported the low-risk classification. The multidisciplinary oncology group opted against postoperative adjuvant radiotherapy due to the lesion’s low-risk classification based on WHO guidelines. The literature generally suggests a favourable prognosis for SFTs. However, further studies on myxoid SFT are needed to fully understand its biological behaviour due to its rarity. A nuclear magnetic resonance imaging scan is recommended 3 months after the last follow-up.
Solitary Fibrous Tumor (SFT); Sarcoma; Neck; Soft tissue neoplasms
Serblin A. Treatment of Neck Solitary Fibrous Tumor: A Case Report. Am J Otolaryngol Head Neck Surg. 2025;8(1): 1265..