A Rare Case of Malignant Fibrous Histiocytoma Mimicking Benign Tumour in Maxillofacial Region.

Sarcomas are malignancies arising from mesenchymal (nonepithelial) tissue and are broadly classified into sarcomas of soft tissue and bone. Soft tissue sarcomas of the head and neck are rare; they comprise < 1% of head and neck cancers and < 10% of all soft tissue sarcomas (Chang et al. in Otolaryngol Head Neck Surg 151:976-983, 2014). There have been few large series, and most have included embryonal rhabdomyosarcomas which are different from other sarcomas and are both radio- and chemosensitive (Eelesl et al. in Br J Cancer 68:201-207, 1993). Malignant soft tissue tumours differ from benign ones in that they are rapidly growing, and invade adjacent tissues and vital structures, and distant metastases through haematogenous or lymphatic routes (Sinha in Cancer Ther Oncol Int J 10(3):1-3, 2018). Benign tumours are well encapsulated and do not infiltrate the adjacent structures both clinically and radiographically. In the following case report, a male patient represented with a soft tissue movable swelling in left cheek; though it shows clinical and radiographic characteristics of benign soft tissue lesion, indeed histopathological presentation was suggestive of undifferentiated pleomorphic sarcoma. This gives us insight into how a malignant lesion can mimic benign lesion and subsequent changes in treatment and follow-up strategy. © The Association of Oral and Maxillofacial Surgeons of India 2020.