Solitary fibrous tumor occurring in the parotid gland: a case report

Abstract

BackgroundSolitary fibrous tumor is an uncommon spindle cell neoplasm of unknown origin. It has been reported in many anatomic sites, with a rare occurrence in the head and neck region. Solitary fibrous tumors of the parotid gland are exceptional; their clinical and radiologic features are non specific, often mimicking more common salivary gland tumors. Pathologic examination and immunohistochemistry are required to make the correct diagnosis. The prognosis is favorable, with most tumors being benign, and complete surgical resection is the treatment of choice.Case presentationWe report the case of a 42-year-old man who presented with a painless mass involving the parotid gland. A parotidectomy was performed, and follow up was unremarkable. Gross examination showed a well circumscribed, firm tumor measuring 3,4 cm. Histologically, the tumor was composed of a spindle cell proliferation of variable cellularity, with staghorn vessels. A panel of immunohistochemical stains was performed, and confirmed the diagnosis of parotid gland solitary fibrous tumor.ConclusionIn this report we aim to increase awareness of this rare entity among clinicians and pathologists, and to emphasize the role of immunohistochemistry in confirming the diagnosis.

Diagnosis of solitary fibrous tumor in the submandibular gland: Case report and literature review

“…Previous reports on color Doppler US of SFTs in the head and neck have shown that these tumors are usually vascular . In contrast, none of the abdominal SFTs examined by Hui et al showed internal vascularity.…”

“…On high‐resolution gray scale US, SFTs have been reported as well circumscribed and hypoechoic, similar to benign tumors that commonly occur in the salivary glands . SFTs may also appear as heterogeneous and polycyclic masses,indicating the presence of necrosis, hemorrhage, and cystic areas.…”

“…SFTs may also appear as heterogeneous and polycyclic masses,indicating the presence of necrosis, hemorrhage, and cystic areas. However, even without these changes, SFTs may appear as heterogeneous, which is possibly due to the alternating zones of hypercellularity and hypocellularity, and the presence of collagenous fibrous tissue. We found that gray scale US had limited usefulness in the diagnosis of SFT, in agreement with Hui et al…”

“…The incidence is approximately the same in males and females, and these tumors usually occur in adults between the ages of 30 and 64 years. SFTs most frequently develop in the pleura, but they may involve any anatomic site, although there are few previous reports of SFTs in the head and neck region . The low incidence of SFTs makes preoperative imaging diagnosis challenging, and the diagnosis mainly relies on histopathologic and immunohistochemical (IHC) analysis after excision.…”

“…SFTs most frequently develop in the pleura, but they may involve any anatomic site, although there are few previous reports of SFTs in the head and neck region. [2][3][4][5][6][7] The low incidence of SFTs makes preoperative imaging diagnosis challenging, and the diagnosis mainly relies on histopathologic and immunohistochemical (IHC) analysis after excision. The primary treatment is complete surgical excision, 7 and long-term follow-up is necessary to monitor for possible local recurrence or malignancy transformation.…”