case_images: PMC10766398_01
case_images: MRI findings of an intramuscular mass in the left upper arm. Images show a 9-cm-long mass in the lateral head of the triceps with iso-intensity on T1-weighted images (a), heterogeneously high intensity on T2-weighted images with fat suppression (b), and strong enhancement with gadolinium (c).
case_images: cro-2024-0017-0001-533924_F01.jpg
case_images: PMC10766398_01_cro-2024-0017-0001-533924_F01.jpg
case_images: F1
case_images: The lesion had iso-intensity on T1-weighted images (shown in Fig. 1a) and heterogeneous high intensity on T2-weighted images (shown in Fig. 1b), with strong enhancement with gadolinium (shown in Fig. 1c).
case_images: Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) findings at the time of presentation. Both upper arm masses show high FDG uptake (arrows). Relevant parts of a whole-body scan (a) and an axial image (b) are presented.
case_images: cro-2024-0017-0001-533924_F02.jpg
case_images: PMC10766398_01_cro-2024-0017-0001-533924_F02.jpg
case_images: F2
case_images: To further investigate, we performed fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT), which revealed high uptake in the masses of both upper arms, with a maximum standardized uptake of 13.14 (shown in Fig. 2).
case_images: Pathological findings on hematoxylin-eosin-stained sections of a biopsy specimen. Granulomatous changes consisting of epithelioid cells accompanied by inflammatory infiltration of lymphocytes and eosinophils, and multinucleated giant cells are apparent. The giant cells contain lucent cytoplasmic vacuoles of varying sizes. Magnification, x100 (a), x400 (b).
case_images: cro-2024-0017-0001-533924_F03.jpg
case_images: PMC10766398_01_cro-2024-0017-0001-533924_F03.jpg
case_images: F3
case_images: The multinucleated giant cells contained cytoplasmic vacuoles of varying sizes (shown in Fig. 3).