FIGURE 1

Histologic and immunohistochemical findings. A, low-power view of a lymph node infiltrated by mantle cell lymphoma (MCL), centrocytoid type. A vaguely nodular pattern can be seen. Original magnification, 100×. B, high-power view showing a monotonous population of MCL cells. Original magnification, 400×. C, positive nuclear immunostaining for cyclin D1 is present in the neoplastic lymphoid cells, whereas the germinal center cells are negative. Original magnification, 400×.