case_images: PMC11208810_01
case_images: CD5-negative, EBV-negative low-grade MCL on cecal biopsy in November 2021. (a) Diffuse monotonous small, atypical lymphocytes with slightly irregular nuclear contour (hematoxylin-eosin, original magnification x200). (b) The atypical lymphocytes exhibit strong expression of CD20 and pax-5 (not shown), diffuse cyclin D1 positivity (1B), and lack of CD5 expression (1B inset). (c) Immunohistochemical stain for Ki-67 revealed a low proliferation index of approximately 10%. (d) EBER in situ hybridization for EBV showed no EBV infection.
case_images: CRIHEM2024-3267739.001.jpg
case_images: PMC11208810_01_CRIHEM2024-3267739.001.jpg
case_images: fig1
case_images: A CT scan showed asymmetric thickening of the cecum and an increase in spleen size to approximately 24 cm. A cecum biopsy in November 2021 (Figure 1) showed persistent classical mantle cell lymphoma.
case_images: Left axillary lymph node biopsy of May 2023 showing high grade pleomorphic mantel cell lymphoma. (a) H&E staining at 20x magnification showing large, atypical lymphocytes with fine chromatin in the background of necrosis. (b) Immunohistochemical staining for cyclin D1 was diffusely positive, while CD5 was negative (insert). (c) Immunohistochemical stain for Ki-67 revealed a high proliferation index (~90%) and large nuclear size. (d) EBER in situ hybridization for EBV detected diffusely positive cells.
case_images: CRIHEM2024-3267739.002.jpg
case_images: PMC11208810_01_CRIHEM2024-3267739.002.jpg
case_images: fig2
case_images: Biopsy of the left axilla lymph node (Figure 2) showed transformed pleomorphic variant of mantle cell lymphoma. The lymphoma cells were mostly large with irregular nuclear contours, frequent mitotic figures, and apoptotic bodies (2A).
case_images: B-cell gene rearrangements in the specimen of November 2021 (a) and May 2023 (b) showing the exact same clonal peaks, indicating evolution from the same clone.
case_images: CRIHEM2024-3267739.003.jpg
case_images: PMC11208810_01_CRIHEM2024-3267739.003.jpg
case_images: fig3
case_images: PCR analysis revealed that the sizes of the clonal peaks in immunoglobulin heavy chain and light chain gene rearrangements were identical to those observed in cecum biopsy conducted in November 2021 (Figure 3), confirming their same clonality.