case_images: PMC7201522_01
case_images: Core needle biopsy of the lesion in the right gastrocnemius muscle. H&E stain showing a dense infiltrate of large pleomorphic cells with prominent nucleoli and horseshoe or kidney-shaped nuclei (hallmark cells) consistent with ALCL.
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case_images: PMC7201522_01_CRIHEM2020-6309736.001.jpg
case_images: fig1
case_images: He underwent a core needle biopsy of the lesion with morphologic examination demonstrating a dense infiltrate of large pleomorphic cells with prominent nucleoli, many of which having horseshoe or kidney-shaped eccentric nuclei resembling hallmark cells (Figure 1).
case_images: Immunohistochemical features of the lymphoma. (a) Hematoxylin and eosin staining; (b) CD30 and (c) CD4 immunostaining showing a strong and uniform expression in the neoplastic cells; (d) TIA1 immunostaining; this marker was only expressed in a minority of cells (-/+).
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case_images: fig2
case_images: TIA1 was only expressed in a minority of cells (-/+); MIB-1 was >90%. These findings were consistent with ALK-negative anaplastic large cell lymphoma (Figure 2).
case_images: Bone marrow biopsy performed at diagnosis showed plasma cell infiltration with lambda-chain restriction. (a) H&E staining; (b) CD138 staining; (c) lambda staining.
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case_images: fig3
case_images: In order to complete lymphoma staging procedures, a bone marrow biopsy was performed, and a relevant infiltration (roughly 70%) by atypical plasma cells with lambda light-chain restriction was detected (Figure 3).
case_images: F18-FDG PET/CT performed at staging showed an intensely hypermetabolic lesion in the right leg and revealed three additional vertebral hypermetabolic lesions in D5, L2, and S1 (a). After chemotherapy, the hypermetabolic lesions in the right leg, D5, and L2 had completely disappeared, with persistence of moderate metabolic activity in the left sacral lesion (DS = 3) (b).
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case_images: PMC7201522_01_CRIHEM2020-6309736.004.jpg
case_images: fig4
case_images: In January 2018, after chemotherapy, an MRI showed a complete response of the ALCL lesion, and a 18F-FDG PET/CT revealed the complete disappearance of the right gastrocnemius muscle and of D5 and L2 lesions, with persistence of moderate metabolic activity in the left sacral lesion (Deauville score = 3) (Figure 4(b)).