case_images: PMC10919911_01
case_images: a Initial MRI of the abdomen. b-i Whole-body FDG PET CT. b-ii Interim NM whole-body PET CT. b-iii End of treatment, NM whole-body FDG PET CT. c Hypercellular lymphoid tissue (large lymphocytes and centroblasts). d Abnormal B lymphocytes showed strong positivity with CD20 at 20X power field. e Positive BCL6 at 20X power field. f Positive CD10 at 20X power field. g A KI-67 index: 60%.
case_images: cro-2024-0017-0001-537780_F01.jpg
case_images: PMC10919911_01_cro-2024-0017-0001-537780_F01.jpg
case_images: F1
case_images: MRI of the abdomen showed an enlarged spleen, a 15-cm focal splenic lesion with peripheral diffusion restriction impressive of malignant neoplasm, showing peri-splenic and para-aortic lymph nodes (Fig. 1a). The radiologic impression was lymphoma versus primary splenic malignancy (angiosarcoma) (Fig. 1b-i). The patient underwent an ultrasound-guided splenic lesion biopsy in June 2022, which showed sheets of hypercellular lymphoid tissue (Fig. 1c) consisting of a dual population of aggregates of large lymphocytes of centroblast morphology and smaller lymphocytes of centrocyte morphology in the background. The immunohistochemical studies showed the following: positive reactivity in the centroblasts for CD20 (Fig. 1d), CD79b, and PAX5, which are B-cell markers; and positive reactivity for BCL6 (Fig. 1e) and CD10 (Fig. 1f), which are germinal center markers that are usually positive in diffuse large B-cell lymphoma (DLBCL) of the germinal center type. The Ki-67 (Fig. 1g) rate, a proliferation index, is 60% (high), as is usually seen in high-grade lymphomas. An interim whole-body PET CT on September 29, 2022, showed complete metabolic remission in the initial lymphoma manifestations (Fig. 1b-ii). At the end of treatment, NM whole-body FDG PET CT on May 13, 2023, showed complete metabolic remission: no pathologic uptake was seen as in the initial scan (Fig. 1b-iii).