case_images: PMC10601723_01
case_images: Successive tomographic controls shows a progressive increase in the number and size of the osteolytic lesions throughout the entire extension of the skeleton, without cortical involvement or extension to soft tissues. a-d October 2020. b-e January 2021. c-f October 2021.
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case_images: PMC10601723_01_cro-2023-0016-0001-530897_F01.jpg
case_images: F1
case_images: At the end of the third cycle, in October 2020, a follow-up CT scan showed minimal decrease in size of the mediastinal mass: 146 x 100 x 147 mm and the emergence of osteolytic images in the L4 vertebral body (Fig. 1a-d). A PET/CT scan showed multiple lytic lesions in the spine and pelvis (Fig. 1b-e), all of which were suspicious of metastatic disease. In October 2021, the patient had progressive lesions (Fig. 1c-f), so he started a treatment with sirolimus 2 mg/day.
case_images: In the MRI study, these lesions present high signal intensity in T2 (a) and STIR sequences (b), as well as LAVA-Flex water images (c), with intense enhancement after contrast administration, which represents hypervascularization. In diffusion sequences (d, e), there are no areas of restriction (ADC values 1.0 x 10.3 mm2/seg), demonstrating the absence of high cellularity within the lesions.
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case_images: PMC10601723_01_cro-2023-0016-0001-530897_F02.jpg
case_images: F2
case_images: March 2021, and new lytic lesions were evidenced (Fig. 2a-ef). Multiple biopsies in different osteolytic lesions were performed, without findings that suggested tumoral involvement.
case_images: Histological sections exhibit a proliferation of vascular elements with different morphologies. a (H-E) Thin-walled blood-filled vessels lined by a single layer of flat, cytologically banal endothelial cells. The vessels permeate the marrow and surround preexisting trabecule. Immunohistochemistry: staining evidenced CD34 positivity in lymphatic vessels (b). CD31 (c) and D2-40 (d) positivity are also observed in vascular structures.
case_images: cro-2023-0016-0001-530897_F03.jpg
case_images: PMC10601723_01_cro-2023-0016-0001-530897_F03.jpg
case_images: F3
case_images: The immunohistochemistry showed positivity for CD34, CD31 (Fig. 3b, c), and D2-40 (podoplanin) (Fig. 3d) and negativity for AE1-AE2, kappa, lambda, and CD138 (Fig. 3a).