An otherwise well, a 48-year-old male patient presented with pain and swelling over right maxillary region for 4 months associated with inability to open mouth fully. Clinically, he was having fullness over right maxillary region and severe trismus (15 mm oral opening). Contrast-enhanced computed tomography (CECT) scan of face and neck region revealed a soft tissue mass in right maxillary antrum with bony destructions—intraorbital extraconal extension abutting the inferior rectus muscle with possible involvement of the infraorbital nerve, medial extension to middle meatus, inferior meatus and involving nasolacrimal duct, anterior extension to premaxillary space, inferior extension to alveolar process and posterolateral extension to infratemporal fossa, and pterygoid fossa with possible involvement of temporalis and lateral pterygoid muscles (Fig. 1). No evidence of lymph nodal or distant metastases was found on imaging. Biopsy from tumor was taken for histopathologic examination (HPE). HPE and subsequent immunohistochemistry (IHC) suggested it to be inflammatory myofibroblastic tumor (Fig. 2). Morphologically tissue consisted of plasma cells, eosinophils, and lymphocytes in a variably collagenized spindle cell stroma. The spindle cells had bland nuclear morphology. On IHC, tumor cells were positive for CD3, CD20, CD 138, CD19, kappa, lambda (kappa:lambda was 2:1), SMA, and calponin and negative for CD56, CK, Alk-1, desmin, h-Caldesmon, and Ki-67 was < 1%.
In view of extensive disease, he was deemed unresectable. Hence, he was treated with definitive radiotherapy (RT) with dose 60 Gy in conventional fractionation over 6 weeks concurrent with oral steroids. For simulation and treatment, he was immobilized with thermoplastic mold in supine position with head extended using head rest. Intraoral stent was inserted to depress tongue outside radiation field as much as possible. CT simulation using 3 mm thickness with IV contrast was performed. Wet cotton bolus was used during treatment. For target volume delineation, all visible tumor in CECT scan was taken into account as gross tumor volume (GTV); for clinical target volume (CTV), 1 cm margin was added to GTV all around and then carved out respecting anatomical boundaries. Ipsilateral nasal cavity medially till nasal septum, entire maxillary sinus, anteriorly and laterally till skin, ipsilateral ethmoid sinus, posteriorly infratemporal fossa, and pterygopalatine fossa were encompassed inside CTV. Superiorly intraorbital margins of CTV were reduced to exclude eye. Finally, 5-mm margin to CTV was given to produce planning target volume (PTV); however, margin was reduced to 1 mm beside ipsilateral eye and optic nerve. Radiation planning was done by forward planning IMRT (intensity-modulated radiation therapy) (Fig. 3). Prednisolone was given in tapering doses with starting dose 60 mg and was tapered by 10 mg every subsequent week. He responded well. After 1 month of RT completion, clinically no swelling was appreciated and trismus resolved. Contrast-enhanced magnetic resonance imaging (CEMRI) was done after 2 months of RT completion which revealed post-RT changes with complete resolution of tumor (Fig. 4). He is doing fine till 6 months follow-up now.