2013 年 59 巻 10 号 p. 632-636
Recently, a growing number of studies have suggested that solitary fibrous tumors (SFTs) occur throughout the body in multiple organs, other than the pleura. Reports on local recurrence and metastasis have proposed that extra-pleural SFTs (including soft-tissue tumors) are medium-grade malignancies among fibroblastic and myofibroblastic tumors according to the World Health Organization tumor classification. We report a case of solitary fibrous tumor in the submandibular region.
Our subject was a 23-year-old woman who presented with a painless swelling in the right side of the submandible. We confirmed the presence of a well-defined, oval tumor (38× 25 mm) in the right side of the submandible on magnetic resonance imaging. T1-weighted images showed uneven low signal intensity, while T2-weighted images showed uneven high signal intensity. Gadolinium-enhanced T1-weighted imaging showed contrast enhancement in a large portion of the tumor. Based on the clinical diagnosis of a benign tumor of the submandibular gland, the tumor was resected with the patient under general anesthesia. Histopathological analysis revealed that the tumor was restricted to the fibrous membrane, with a dense proliferation of spindle/ short-spindle cells. Immunohistochemical staining was positive for CD34 and bcl-2, which confirmed the diagnosis of SFT. Neither recurrence nor metastasis has occurred as of 34 months after surgery.