case_images: PMC6415466_01
case_images: Computed tomography, the cytological findings of the sputum and the histological findings of the lung biopsy specimen: (a) Computed tomography on admission showed multiple nodular shadows in the bilateral lower lung field (left). Most of the nodular shadows disappeared spontaneously after the withdrawal of MTX (right). (b) A sputum smear on admission showed many atypical small cells with low cell cohesion (left). Necrotic debris was observed in the background of the sputum cytology (right) (papanicolaou staining; original magnification, x400). (c) A high-power view of the sputum revealed that the atypical cells had a high N/C ratio, foamy cytoplasm, increased chromatin and distinct nucleoli (papanicolaou staining; original magnification, x1000). (d) Lung biopsy after sputum cytology revealed atypical lymphoid cells with high N/C ratio, cleaved nuclei and distinct nucleoli (HE staining) (original magnification: x400).
case_images: 10.1177_2050313X19836017-fig1.jpg
case_images: PMC6415466_01_10.1177_2050313X19836017-fig1.jpg
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case_images: Cr (0.63 mg/dL). Chest computed tomography revealed multiple nodular shadows with interstitial pneumonia in the bilateral lower lung fields (Figure 1(a), left). Necrotic debris was observed in the background of the sputum cytology (Figure 1(b)). The sputum cytology showed many atypical lymphoid cells with low cell connectivity, a high nuclear-to-cytoplasmic (N/C) ratio, foamy cytoplasm, coarsely granular chromatin and distinct nucleoli (Figure 1(b) and (c)). Lung biopsy revealed atypical mid- to large-sized lymphoid cells with a high N/C ratio, cleaved nuclei and distinct nucleoli (Figure 1(d)). MTX-LPD (non-germinal center B-cell-like DLBCL histological type). Most of the nodules disappeared spontaneously about 3 weeks after the withdrawal of MTX (Figure 1(a), right); thereafter, only tacrolimus was used.
case_images: Immunohistochemical staining of a lung biopsy specimen showed that the atypical lymphoid cells were positive for CD20 (a) and MUM-1 (b), but negative for CD3 (c). ISH-EBER (d) was negative (original magnification: x200).
case_images: 10.1177_2050313X19836017-fig2.jpg
case_images: PMC6415466_01_10.1177_2050313X19836017-fig2.jpg
case_images: fig2-2050313X19836017
case_images: Immunohisto-chemical staining of the lung biopsy specimen showed that the atypical lymphoid cells were positive for CD20 (Figure 2(a)) and MUM-1 (Figure 2(b)), and weakly positive for bcl-6, but negative for CD3 (Figure 2(c)) and CD10. ISH-EBER showed no EBV-infectious lymphoid cells (Figure 2(d)).