A rare case of solitary fibrous tumor of parotid gland: diagnostic work-up and treatment

The solitary fibrous tumor (SFT) originates from mesenchymal cells and was first described in 1931. This neoplasm often arises in pleura but it has been reported in others sites including head and neck, where it is very rare; the onset in the parotid gland has been described in 26 cases worldwide. This type of neoplasm has mainly a benign behavior with slow and progressive growth, indeed patients often complain poor symptomatology. The imaging usually reveals a well delimited lesion with an ovoid shape and an intense and heterogeneous enhancement, but the diagnosis is based on histological and immunohistochemical features, rather than clinical and radiological findings. SFT shows immunoreactivity for some markers as vimentin, CD99 and bcl-2. They are consistently negative for S-100 protein, cytokeratins, alpha-SMA, S-100, CD31. The patient observed was a 54-year-old male, who underwent left superficial parotidectomy, after a diagnostic work up including clinical examination, ultrasound, CT scan and core biopsy. Histological and immunohistochemical results reveal a solitary fibrous tumor of the parotid gland (BCL2+, CD34+, CD99+). Surgical therapy represents the gold standard for this type of neoplasm, instead radiochemotherapy is reserved to malignant tumors, cases of nonradical surgery and patients considered unfit for surgical treatment. It is suggested a long term clinical and radiological follow-up.