Abstract
Solitary Fibrous Tumours (SFT)s are rare soft-tissue tumours of mesenchymal origin, which are even more rare in the head and neck region. They are typically benign in nature but in rare circumstances may show transformation into malignancy. Histologically, they show a well-encapsulated biphasic lesion, having hypo- and hyper-cellular with cells with bland spindle shaped nuclei, arranged in fascicles, in a stroma comprised of ropey collagen, having haemangiopericytoma like patulous vasculature. Occasionally, the lesion may show cystic spaces. Usually, these tumours do not show necrosis, atypia or abnormal mitoses. SFTs are typically positive for STAT6, CD34, BCL2 and CD99. Complete surgical excision is the treatment of choice, but often the tumour shows recurrence. This case series presents three cases. The first case is a 32-year-old male presenting with a painless firm mass, in right submandibular region since last one year. The second case is a 41-year-old male presenting with a firm swelling over the right-side of his nose, with tenderness in the area, associated with epistaxis from his right nostril and difficulty in breathing. He was previously operated for the same in 2018, but few months after every surgery the symptoms had recurred, and he had undergone a total of three operative procedures and one session of radiotherapy till 2024. The third case is a 62-year-old male presenting with a slow growing, non tender swelling over the calf of his left leg for one year. All the cases have been managed with total surgical resection, and microscopically showed the above-mentioned histologic features of SFTs. On immunohistochemistry, they showed positivity for STAT6, BCL2, CD34 and CD99. Based on the histological and Immunohistochemistry (IHC) findings, the tumours were diagnosed to be SFT. This series is focused on the extrapulmonary unusual sites of presentation of SFT, because early diagnosis and treatment is always helpful to the patients.