A 47-year-old woman was seen with left-sided facial weakness and swelling for 2 months. She was diagnosed as having recurrent high-grade serous cystadenocarcinoma of the ovary and developed these symptoms after cycle 4 of chemotherapy. She was receiving oral antidiabetic agents, and her blood glucose level was 110 mg/dL. Physical examination findings were consistent with left lower motor neuron type of facial nerve palsy. She was conscious and well-oriented, with no other relevant clinical signs or focal neurological deficits. There was no history of prior COVID-19 infection. MRI of the brain was requested, with clinical suspicion of metastasis in view of mildly elevated CA125 levels. The results of MRI of the brain did not reveal any neuroparenchymal or meningeal lesions. However, both maxillary sinuses showed mucosal thickening, which was intermediate to hypointense on T2-weighted imaging and hypointense on T1-weighted imaging with post-contrast enhancement. CT sections confirmed bony destruction with foci of remodeling involving the walls of the maxillary sinuses. Fat stranding and enhancing soft tissue was seen in the retroantral spaces bilaterally as well as the pterygopalatine fossae. Anteriorly, enhancing soft tissue was present in the premaxillary space, from which contiguous linear enhancement was seen extending to the left parotid gland—along the expected course of the buccal branch of the left facial nerve. The entire extracranial left facial nerve proximal to this showed diffuse enhancement and thickening. Associated stylomastoid foramen widening was present with subtle enhancement along its mastoid and tympanic segments. Additionally, there was involvement of the mandibular branch of the trigeminal nerve via intercommunication between the auriculotemporal branch of the trigeminal nerve and the intraparotid facial nerve. Diffuse enhancement and thickening were seen up to the left foramen ovale, without involvement of the trigeminal ganglion.Figure 1. A, Axial T2-weighted magnetic resonance imaging (MRI) shows T2 heterogeneous soft tissue in the maxillary sinus with perimaxillary inflammatory changes (yellow arrowhead). B, In this axial contrast-enhanced, T1-weighted (T1 + C) image, linear enhancement corresponds to expected course of buccal branch of facial nerve (VII) (white arrow). The enhancement extends medially and involves the mandibular branch of the trigeminal nerve (V3). P indicates parotid gland, and the yellow dashed line outlines the edge of the parotid gland. B and C, The white arrow shows the intercommunication between the auriculotemporal branch of V3 and the intraparotid facial nerve (green marker). C, Additionally, involvement of enhanced thickening is seen up to the left foramen ovale, without involvement of the trigeminal ganglion. D, In oblique sagittal images, the thick enhancing branches of the facial nerves within the left parotid gland are seen (orange arrows). The enhancement of facial nerve extends up to the stylomastoid foramen (SMF) (blue arrow), and there is subtle enhancement along its mastoid segments (MSs). Iodinated contrast medium was used. A. Maxillary carcinoma with perineural spread B. Schwannoma C. Invasive fungal sinusitis (mucormycosis) with perineural spread D. Metastases from ovarian primary