PMC9684465_01
Computed tomography (CT) images of nasal sinus alveolar rhabdomyosarcoma (ARMS) in case 1. (A) Plain image showed the lesion at the left nasal cavity and sphenoidal sinus with homogenous density and osteolytic destruction inside. (B) The arterial phase contrast image showed circular enhancement in the left mandibular and cervical masses. (C-F; C,D, transverse; E,F, coronal) Venous phase images showed bilateral lesions in the neck and parapharyngeal regions with heterogenous enhancement, which invaded the inner wall of the left orbit, the ethmoid inward, and the frontal lobe upward.
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Contrast-enhanced CT revealed the masses with circular enhancement and the lesions invaded the frontal lobe (Figure 1).
Magnetic resonance images of nasal sinus ARMS in case 1. (A) Transverse T1-weighted image (T1WI) showed the lesions at the left nasal cavity and nasal sinus with hypointensity. (B) Transverse T2-weighted image (T2WI) showed the lesions at the left nasal cavity and nasal sinus with homogenous hyperintensity. (C) Sagittal T2WI showed a cervical lesion with heterogenous hyperintensity. The lesions showed hyperintensity on diffusion-weighted imaging (DWI) (D) and hypointensity apparent diffusion coefficient (ADC) images (E). Coronal (F) and sagittal (G) enhanced images showed lesions in the nasal sinus with distinct enhancement. (H) Sagittal-enhanced images showed cervical lesions with distinct enhancement and clear boundaries.
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T1WI, hyperintensity on T2WI and diffusion-weighted imaging (DWI), and hypointensity on apparent diffusion coefficient (ADC) images, while the lesions showed significant enhancement on enhanced images (Figure 2). Then, the patient was injected with 0.1 mCi/kg of 18F-FDG after 6 h of fasting and PET/CT images were acquired 60 min later for further whole-body evaluation.
18F-FDG PET/CT images of nasal sinus ARMS in case 1. (A,B) The anteroposterior 3-dimensional maximum intensity projection image (MIP) demonstrated hypermetabolic lesions in the maxillofacial, neck region, 3rd lumbar vertebra, and the right sacrum. (C-F) The transverse images showed bilateral frontal sinus and left ethmoidal sinus, sphenoidal sinus, maxillary sinus, and nasal cavity filled with soft tissue shadows, with increased FDG uptake at a SUVmax of 12.6 and maximum section of about 4.1 cm x 4.6 cm. The lesion was shown with unclear boundaries from the adjacent structures. (G-I) The transverse images showed multiple enlarged lymph nodes in the left parapharyngeal regions and left cervical regions I-IV with significantly higher uptake of SUVmax about 18.6, a larger one was measured at 1.8 cm x 1.6 cm. (J,K) The transverse images showed the 3rd lumbar vertebra and the right sacrum with dense foci of radioactive distribution, SUVmax of about 5.2.
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The 3rd lumbar vertebra and the right sacrum were found with a local FDG-avid lesion with SUVmax at about 5.2 (Figure 3).
Histopathological results in case 1. (A) Hematoxylin-eosin (HE) staining (x200). Immunohistochemistry showed that the tumor cells were positive for CD56 (B), Syn (C), SOX-10 (D), MyoD1 (E), Myogenin (F), MSH2 (G), MSH6 (H), MLH1 (I), PMS2 (J), and MSH6 (K) [Envision (B-K) x200]. (L) Fluorescence in situ hybridization revealed FKHR gene rupture (x1,000).
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Based on the results of histological morphology, immunohistochemistry, and molecular testing, this case was finally diagnosed with ARMS (Figure 4).
PMC9684465_02
CT and MR images of nasal sinus ARMS in case 2. (A-D) CT images (A. transverse, B. coronal, C. sagittal, and D. bone window) showed soft tissue mass in the left nasal cavity, maxillary sinus, ethmoidal sinus, sphenoidal sinus, frontal sinus, and nasal cavity with local protrusion into the left orbit, interrupted bony continuity of the medial wall of the left maxillary sinus and lateral wall of the septal sinus. (E) The lesions showed slightly low signal T1WI. (F) High signal on T2WI. (G) High signal on DWI. (H) Significant heterogenous enhancement on enhanced images.
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CT demonstrated a soft tissue mass in the left nasal cavity, maxillary sinus, ethmoidal sinus, sphenoidal sinus, frontal sinus, and nasal cavity with the local protrusion into the left orbit interrupted bony continuity of the medial wall of the left maxillary sinus and lateral wall of the septal sinus (Figures 5A-D). T2WI and DWI, and significant heterogenous enhancement on enhanced images. The lesion could not be separated from the left abducens oculi and orbital wall, with compression of the left optic nerve and protrusion of the left eyeball (Figures 5E-H). 18F-FDG PET/CT demonstrated that soft tissues existed in the left ethmoidal sinus, the left maxillary sinus, and the left nasal cavity, with significant radioactive uptake of SUVmax at 19.1. The lesions invaded the left orbit without clear edges from the left abducens oculi, while bone destruction could be seen in the left ethmoidal-lamina papyracea, medial orbital wall, and maxillary sinus.
18F-FDG PET/CT images of nasal sinus ARMS in case 2. (A) The anteroposterior 3-dimensional MIP image demonstrated FDG-avid lesions located in the left maxillofacial region, without abnormal FDG metabolism. (B-D) The transverse images showed soft tissues existed in the left ethmoidal sinus, the left maxillary sinus, and the left nasal cavity, with high radioactivity distribution, SUVmax at about 19.1. The lesions invaded the left orbit without clear edges from the left abducens oculi, and bone destruction could be seen in the left ethmoidal-lamina papyracea, medial orbital wall, and maxillary sinus. (E) The transverse images showed a lymph node with elevated uptake of SUVmax at about 9.7 in the left parapharyngeal regions.
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Lymph nodes were revealed with elevated uptake of SUVmax at 9.7 in the left parapharyngeal regions, measuring about 0.5 cm x 0.7 cm (Figure 6).
Nasal endoscopic images of the nasal sinuses and histopathological results of ARMS in case 2. (A) Nasal endoscopy of the patient revealed a reddish neoplasm in the left middle nasal tract. (B) HE staining of biopsy tissue (x40). (C) The gene test image showed positive FKHR gene rupture (x1,000). (D) Postoperative pathological HE staining (x100).
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Nasal endoscopy of the patient revealed a neoplasm in the left middle nasal tract (Figure 7A). Biopsy of the lesion showed round and ovoid tumor cells with eosinophilic cytoplasm, heterogeneous deep-stained nuclei, and active nuclear division (Figure 7B). FLI-1 (partial+), Desmin (+), SMA (-), Myogenin (partial+), Myo D1 (+), ALK (+), and Ki-67 (80%+). Fluorescence in situ hybridization showed that FKHR gene rupture occurred in this case (Figure 7C). The postoperative pathology was consistent with ARMS (Figure 7D).
Computed tomography (CT) images and magnetic resonance imaging (MRI) of postoperative recurrence of alveolar rhabdomyosarcoma (ARMS) in case 2. (A) A coronal CT image showed soft tissue density masses in the sinuses, suggesting recurrence. (B) The lesions showed slight hypointensity on T1WI. (C) Slight hyperintensity on T2WI. (D) Hyperintensity on DWI. (E) Hypointensity on apparent diffusion coefficient (ADC) image. (F) Significant heterogeneous enhancement and compressed left optic nerve.
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After 2 weeks, CT and MRI imaging indicated recurrence (Figure 8).