A Rare Case of Malignant Solitary Fibrous Tumor on the Scalp

Abstract

Solitary fibrous tumor (SFT) is an uncommon tumor that typically originates in the pleural cavity but may also be found in extra-pleura sites like the head and neck, spine, lungs, mediastinum, peritoneum, and pelvis. There are few reports of SFT of the scalp, and malignant SFT of the scalp appears to be so rare that only two cases of it were reported previously. A 47-year-old woman was admitted to our institution with a large, rapidly growing mass on the left parietal scalp. An analysis of her scalp condition and imaging findings of the mass revealed two different appearances between the superior and inferior halves; the scalp of the inferior half looked normal, but that of the superior half did not. Also, computed tomography findings of the mass confirmed different patterns between the superior and inferior halves. The mass with the abnormal superior half scalp was removed totally. The pathological diagnosis was malignant SFT, but the inferior mass was revealed to have a benign nature. The patient underwent prophylactic radiotherapy and experienced no local recurrence or distant metastasis at the final follow-up at 12 months. We present a third case of malignant SFT originating on the scalp and describe our clinical and surgical experience managing malignant SFT of the scalp.