A 36-year-old African man presented to the emergency department (ED) with a large right-sided facial mass causing massive facial disfigurement. The patient's right ear was displaced superiorly while his mouth was deviated to the left (Figure 1(a)). The foul-smelling tumorous tissue appeared necrotic with purulent and bloody excretions. The mass had been growing over the past eight years, and the patient had undergone multiple resections in Africa, including a right parotidectomy prior presentation at our ED. In addition, the patient had a fever as high as 38.5 C without other systemic symptoms.
Contrast-enhanced computed tomography (CT) of the head and neck showed an exophytic and lobulated mass (dimensions, 28.0 x 9.5 x 23.5 cm) centred at the right preauricular region. It appeared as a moderately hypoattenuated lesion with moderate contrast enhancement without calcifications. In addition, a mass effect was shown on the surrounding tissues with bone scalloping of the right posterior mandibular ramus, the external auditive canal, and the mastoid, all of which are indicative of a slow-growing process. CT angiography showed multiple branches of the external carotid artery circumferentially encased by tumoral tissue. The right upper lobe showed findings compatible with an active open tuberculosis (TB), which most likely was causing the fever in this patient.
On magnetic resonance imaging (MRI), the tumour appeared hypointense on T1-weighted imaging and moderately hyperintense on T2-weighted imaging and showed marked homogeneous contrast enhancement with peripheral zones of necrosis (Figures 2(a)-2(c)). The adjacent right masseter muscle, medial and lateral pterygoid muscles, and the perioral muscles were not separately visible due to deep muscular invasion. In addition, there was anteroinferior displacement of the submandibular gland and the prestyloid and poststyloid parapharyngeal space without clear signs of invasion.
Positron emission tomography with CT showed F-18 fluorodeoxyglucose accumulation in the right facial tumour and in the right upper lobe (due to TB). However, there were no signs of metastasis.
Based on the imaging findings and the location of the tumour, we posed a differential diagnosis consisting of chronic tuberculous lymphadenitis, plexiform neurofibroma, liposarcoma, DFSP, and giant pleomorphic adenoma. Histopathological examination showed an unencapsulated but well-defined nodule consisting of monomorphic spindle cells in a storiform pattern. Immunohistochemistry for CD34 was strongly positive. These findings revealed the diagnosis of DFSP.
Given the tumour's massive size and proximity to important structures, the patient underwent a debulking excisional surgery, a mass of 2.8 kg tumorous tissue was removed in total (Figure 3). The tumour debulking included the excision of the right ear and was restored by means of a transposition flap of the masseter muscle to cover the buccal communication (Figure 1(b)).
A second reconstruction using a split-thickness skin graft from the right thigh was used to cover the remaining defect after two weeks of granulation of the original wound bed (Figure 1(c)). The resected specimen showed diffuse tumoral involvement of the peripheral and deep margins on histopathology. Therefore, curative adjuvant radiation therapy was performed on the resection site after complete healing of the skin graft.