case_images: PMC6914952_01
case_images: Image findings of Case 1 at the initial diagnosis. (a, b) Computed tomography images of the paranasal cavity (coronal section); bone thinning is evident (white arrow). (c) Gadolinium- (Gd-) enhanced T1-weighted MRI of the paranasal cavity (sagittal section). (d) Gd-enhanced T1-weighted image (coronal section). (e) T2-weighted image (axial section). (f) T2-weighted image (coronal section). Slightly high signals are evident at the paranasal sinus mucosa or nasal mucosa in the T1-weighted images, and a robust enhancing effect is evident in the Gd-enhanced image. Nonsignal regions are evident at the frontal, ethmoid, and sphenoid sinuses, along with an area showing low- to faint-high signal, indicating the possibility of allergic mucin in the nasal cavity. In the T2-weighted image, the paranasal sinus mucosa or nasal mucosa shows high signal levels, and most of the area with possible allergic mucin shows a low signal level.
case_images: CRIOT2019-9598283.001.jpg
case_images: PMC6914952_01_CRIOT2019-9598283.001.jpg
case_images: fig1
case_images: As CT showed soft-tissue contrast at all of the paranasal sinuses, as well as bone thinning at the middle cranial bottom, at both paries medialis orbitae and at the bottom of the sphenoidal sinus (Figures 1(a) and 1(b)), a possible tumorous lesion was undeniable. In the T2-weighted image, the paranasal sinus mucosa or nasal mucosa showed high signal levels and most of the area of possible allergic mucin showed low signal level (Figures 1(c)-1(f)).
case_images: Pathological findings of Case 1. (a, b) Hematoxylin-eosin stain; eosinophilic infiltration at the nasal polyp is evident. (c) Grocott stain. Mycelia are evident in the eosinophilic mucin, but it is not possible to identify the fungus (black arrow). (d) Image from the polarizing microscope. Calcium oxalate crystals are evident in the eosinophilic mucin.
case_images: CRIOT2019-9598283.002.jpg
case_images: PMC6914952_01_CRIOT2019-9598283.002.jpg
case_images: fig2
case_images: Also, mycelia, calcium oxalate crystals, and Charcot-Leyden crystals were evident in the colloidal mucus (Figure 2).
case_images: Case 1 recurrence. (a, b) Computed tomography (CT) image of the paranasal cavity in Case 1 after the first surgery. Pathways from the nasal cavity to each paranasal cavity are cleared. (c, d) CT image of the paranasal cavity in Case 1 after disease recurrence. Contrasts are evident in the ethmoid and frontal sinuses on both sides.
case_images: CRIOT2019-9598283.003.jpg
case_images: PMC6914952_01_CRIOT2019-9598283.003.jpg
case_images: fig3
case_images: Symptoms of diplopia and nasal obstruction subsided (Figures 3(a) and 3(b)), but they recurred after two years. There was exacerbation of the paranasal sinus contrast in CT images, mainly at the ethmoid bones on both sides and at the frontal sinus (Figures 3(c) and 3(d)).
case_images: Continued remission in Case 2. (a, b) Computed tomography image findings of Case 2 after the second surgery. (c, d) Pathological findings of the paranasal cavity in Case 2 after the second surgery. There is no apparent evidence indicating disease recurrence.
case_images: CRIOT2019-9598283.004.jpg
case_images: PMC6914952_01_CRIOT2019-9598283.004.jpg
case_images: fig4
case_images: Disease recurrence has not been confirmed (Figure 4).
case_images: PMC6914952_02
case_images: Case 2 MRI findings. (a) Computed tomography (CT) image of the paranasal cavity (axial section). (b) CT image of the paranasal cavity (sagittal section). (c) CT image of the paranasal cavity (coronal section). Soft-tissue contrasts are evident in the left maxillary sinus, the left frontal sinus, the left ethmoid sinus, and both sphenoid sinuses, along with bone thinning at the lamina papyracea and the base of the skull (white arrow). (d) T1-weighted MRI of the paranasal cavity (coronal section). (e) T2-weighted MRI of the paranasal cavity (coronal section). The paranasal sinus mucosa and nasal mucosa show isosignal intensity in the T1-weighted images, high signal intensity in the T2-weighted images, and the most of the allergic mucin show none to low signal intensity. (f, g) CT images of the paranasal cavity after the surgery (coronal section). There is no apparent evidence indicating disease recurrence.
case_images: CRIOT2019-9598283.005.jpg
case_images: PMC6914952_02_CRIOT2019-9598283.005.jpg
case_images: fig5
case_images: CT images showed soft-tissue contrast filled in the left maxillary sinus, the left frontal sinus, the left ethmoid sinus, and both sphenoid sinuses, along with bone thinning at the lamina papyracea and the base of the skull (Figures 5(a)-5(c)). MRI showed isosignals in T1-weighted images of the paranasal sinus mucosa and the nasal mucosa, high signals in T2-weighted images of the paranasal sinus and the nasal mucosa, and no signals to low signals at the substance suspected to be allergic mucin (Figures 5(d) and 5(e)). Subjective symptoms such as headache or dysosmia subsided, and CT images and visual inspection of the nasal cavity have not shown evidence of disease recurrence in the three years since the surgery (Figures 5(f) and 5(g)).