case_images: PMC11057842_01
case_images: Patient 1: initial clinical examination and initial in-house MR scan. a Clinical appearance at first examination at our hospital, presenting with left face and eyelid swelling, diffuse erythema, and ophthalmoplegia. DWI (b) with corresponding ADC (c) revealed diffusion restriction of left optic nerve (arrows) indicative of optic nerve ischemia. d. Reduced left internal carotid artery (ICA) caliber indicative of secondary vasculitis (compare white arrow in the 3D reconstruction of the 3D-time of flight angiography [3D-TOF MRA]). The T1-weighted coronal (e, g) and axial (f) starVIBE with fat saturation after administration of contrast showed the left cavernous sinus thrombosis with reduced flow void of the ICA (white arrows in e). The left extraocular muscles were edematous with enhancement (see arrow in f and black star in g) as with myositis. The left optic nerve showed significant enhancement (arrow in g). There was a frank osseous destruction of the left paranasal sinus with mucous retention in the anterior ethmoid (black star in F) and imaging appearance of an "empty nose" on the left side in side comparison (f, g).
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case_images: F1
case_images: Magnetic resonance imaging (MRI) showed left optic nerve ischemia, severe orbital cellulitis, proptosis, and cavernous sinus thrombosis (Fig. 1). The left ethmoid air cells were partially destroyed ("empty nose sign," Fig. 1).
case_images: Patient 1: intraoperative endoscopic intranasal view and histopathology. a, b Intraoperative endoscopic intranasal view of the necrotic eschars within the left nasal cavity. c, d Periodic acid-Schiff (PAS) stain (x40). Variable sized, ribbon-like, nonseptate fungal organisms, with 90-degree angle branching. Extensive purulent and necrotizing inflammation, compatible with Mucor partly located within blood vessels, leading to an image of occlusive vasculitis.
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case_images: F2
case_images: The left nasal cavity was now covered in black necrotic eschars (Fig. 2). B (10 mg/kg/d) was administered. Biopsy tissue showed ribbon-like, nonseptate fungal hyphae, extensive necrotizing inflammation (Fig. 2), and angioinvasion.
case_images: Patient 1: postoperative clinical status and postoperative follow-up MRI after left orbital exenteration. a Clinical follow-up: situation after exenteration of the left orbital cavity. b, c The native axial T1-weighted starVIBE with fat saturation revealed a new filling defect of the left ICA (white arrow in b) in comparison to the normal flow void of the right ICA (black arrow in c). This was correlated in 3D-TOF MRA (arrow in C) confirming occlusion of the vessel. e, f The whole-brain post-contrast T1-weighted multiplanar reconstruction (MPR) (e axial and f coronal) showed perineural spread of the inflammation with extension and contrast enhancement of the frontobasal pachymeninx bilateral (arrows).
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case_images: F3
case_images: Extensive necrosectomy of the left nasal cavity and sinus with exenteration of the left orbit was performed (Fig. 3). A follow-up MRI 10 weeks later showed progressive ROCM involving the anterior skull base, the left masticator space, the optic chiasma and contralateral optic nerve, bilateral frontobasal, lepto- and pachymeningeal enhancement with edema in the adjacent gyri recti, and complete left ICA occlusion, without evidence of cerebral ischemia (Fig. 3).
case_images: PMC11057842_02
case_images: Patient 2: initial clinical examination and initial in-house MR scan. Due to the patient's pronounced movement, the scan is slightly superimposed by artifacts. Axial (a) and coronal (b) T2-weighted (T2w) images revealed extensive hypointense mucoid retentions on the right paranasal sinus (white arrows) with complete obliteration of the maxillary, ethmoid, and sphenoid sinus. c These mucoid retentions are without enhancement on the T1-weighted (T1w) post-contrast phase (white arrows) thus demonstrating the "black turbinate sign" indicative of angioinvasive fungal sinusitis.
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case_images: F4
case_images: A follow-up MRI showed severe intraorbital cellulitis (Fig. 4).
case_images: Patient 2: intraoperative endoscopic intranasal view and histopathology. a, b Intraoperative endoscopic intranasal view of the necrotic eschars within the right nasal cavity. c Periodic acid-Schiff (PAS) stain (x40). Ribbon-like, nonseptate fungal organisms, with 90-degree angle branching. Extensive purulent and necrotizing inflammation compatible with Mucormycetes partly located within blood vessels, resulting in occlusive vasculitis.
case_images: crn-2024-0016-0001-538539_F05.jpg
case_images: PMC11057842_02_crn-2024-0016-0001-538539_F05.jpg
case_images: F5
case_images: ROCM. Right orbital decompression and fronto-spheno-ethmoidectomy was performed (Fig. 5). Histopathological examination revealed nonseptate hyphae branching at 90  angles, with necrotizing inflammation and angioinvasion on hematoxylin and eosin and periodic acid-Schiff stained samples, compatible with mucormycosis (MM) (Fig. 5).
case_images: Patient 2: postoperative follow-up MRI after left orbital exenteration. a, b The axial T1-weighted MPR post-contrast shows progression of the inflammation with progressive opacification of the right cavernous sinus (arrows). c The coronal T1-weighted MPR after contrast revealed a perineural extension along the course of the left mandibular nerve on the right side (arrows). d The coronal T1-weighted MPR after contrast shows an avid enhancement of the right frontobasal pachymeninx.
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case_images: F6
case_images: MRI showed progression of the inflammation along the right trigeminal branches and into the right cavernous sinus with consecutive thrombosis, as well as pachymeningeal enhancement of the right temporal and frontobasal region (Fig. 6).