case_images: PMC9794988_01
case_images: Photographs of the bilateral anterior and posterior ears of the patient. Before the treatment (A, B), after 19 months of treatment with omalizumab (C, D), and after 16 weeks of treatment with dupilumab (E, F) (arrows indicate tumorous regions).
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case_images: Physical examination showed anterior and posterior masses around both ears, the right anterior being the most obvious ( Figures 1A, B ). Yet, no obvious improvements have been found after long-term therapy of 19 cycles; the masses did not shrink, and circulating eosinophils did not go down significantly ( Figures 1C, D ,  4 ). The bilateral masses began to shrink since the second week and were more pronounced by the end of the first treatment course (16 weeks) ( Figures 1E, F ,  4B ).
case_images: The anterior and posterior ears' color Doppler ultrasound. The right anterior mass is in the size of 5.2x2.2 cm and has a heterogeneous hypoechoic-isoechoic appearance (right ear in front, right ear behind, and left ear in front); (A-C) before treatment; (D-F) after 16 weeks of treatment with dupilumab.
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case_images: Ultrasound examination showed low echo masses in the front and back of the bilateral ear, patchy low echo area in the left parotid gland, and multiple lymph nodes enlargement in and around the bilateral parotid gland ( Figures 2A-C ). Ultrasound examination also showed clear reduction in the size of the anterior and posterior ear masses upon completion of the therapy compared with the size before ( Figures 2D-F ).
case_images: The pathological characteristics of ear masses. The gross view of pathological sections (A). In the cortical region, lymphoid tissue hyperplasia with numerous eosinophils infiltrating (B); hyperplasia of postcapillary venules with hyalinosis (C, D); the marked region with the rectangle in C shows hyaline blood vessels (Hematoxylin and Eosin staining).
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case_images: Histological sections of the mass tissue behind both ears revealed a large amount of eosinophils infiltration in the fibrous tissue and vascular hyperplasia with hyaline degeneration ( Figure 3 ).
case_images: Time-course changes in the levels of eosinophil count and serum IgE (A); the change in mass volume in each region during treatment (B).
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case_images: Yet, no obvious improvements have been found after long-term therapy of 19 cycles; the masses did not shrink, and circulating eosinophils did not go down significantly ( Figures 1C, D ,  4 ). The bilateral masses began to shrink since the second week and were more pronounced by the end of the first treatment course (16 weeks) ( Figures 1E, F ,  4B ). Although the IgE level in the serum was still >2000 IU/ml, the eosinophil count returned to normal after the dupilumab therapy ( Figure 4A ).