Solitary fibrous tumor of buccal mucosa: A rare entity

BACKGROUND an‎d AIM: Solitary fibrous tumor (SFT) is a quite uncommon tumor that commonly occurs in the pleura but occasionally involves an oral cavity. We are reporting this rare case in the oral cavity. The diagnosis depends on microscopic and immunohistochemical features. Patients with these tumors can be carefully treated with local excision, but tumors with positive margins necessitate close follow-up over several years due to the possible late local recurrence. CASE REPORT: A 60-year male patient came in the maxillofacial department in Abbasi Shaheed Hospital, Karachi, Pakistan with swelling on lower lip (right side) for the past 5 years which slowly increased in size with no history of pain. The excisional biopsy was performed under local anesthesia. Histopathological examination showed a well-circumscribed spindle cell tumor with alternating hypo and hypercellular areas with prominent collagenous stroma. Immunohistochemistry (IHC) investigation led to the positive expression of Cluster of Differentiation 34 (CD34) and Signal Transducer and Activator of Transcription-6 (STAT-6) in the spindle cells, and negative expression of Anti-Smooth Muscle Antibody (ASMA). Recurrent or postoperative complications were not observed over some time. CONCLUSION: SFT in the buccal mucosa of the cheek is a very sporadic condition. It needs to be identified with proper history and clinical examination.