PMC4721194_01
Histological features of primary DLBCL arising from a leiomyoma of the uterine corpus. Diffuse proliferation of lymphoid cells dissecting the muscle fiber is observed (a). Lymphoid cells consist of medium- to large-sized cells with abundant, faintly basophilic cytoplasm and round to oval nuclei, which are occasionally convoluted and which contain dispersed nuclear chromatin and one to multiple prominent nucleoli (b). [A-B: hematoxylin and eosin (H & E) staining; A: original magnification (O.M.), 100x; B: O.M., 200x]
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Fig1
Within the leiomyoma without any mitosis or necrosis, the lymphoid infiltrate was diffuse, and there were only a few recognizable whorled bundles and fascicles of smooth-muscle cells (Fig. 1a). The lymphoid cells consisted of medium- to large-sized cells with abundant, faintly basophilic cytoplasm and round to oval nuclei, which were sometimes convoluted and which contained dispersed nuclear chromatin and one to multiple prominent nucleoli (Fig. 1b).
Immunohistochemical findings of primary DLBCL arising from a leiomyoma of the uterine corpus. Most lymphoid cells are positive for CD20 (a) and PAX5 (b). The proliferative index is high (approximately 50 %) (c). Smooth-muscle cells are positive for caldesmon (d). (A: CD20 stain, B: PAX5 stain, C: Ki-67 stain, D: caldesmon stain; A, B: O.M., 200x; C, D: O.M., 100x)
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Fig2
Most of the lymphoid cells were positive for CD79alpha, CD20 (Fig. 2a), PAX5 (Fig. 2b), bcl-2 and MUM-1 but negative for CD3, CD5, CD4, CD8, CD10, bcl-6, CD56, CD30, CD21, CD23, CD138, perforin and Gram beta. The proliferative index (based on Ki-67 staining) was high (approximately 50 %) (Fig. 2c). Smooth-muscle cells were positive for desmin and caldesmon (Fig. 2d).