Mantle cell lymphoma growing in mantle zone pattern may be easily mistaken for follicular hyperplasia because the malignant lymphocytes grow at the periphery of follicles in an expanded mantle zone but leave unaltered the central germinal center, which shows the usual reactive features described above (Figure 4, E and F).
27) The definitive way to identify in situ mantle cell neoplasia is with a cyclin D1 immunohistochemical stain, which typically shows strong expression among B cells within the inner half of the mantle zone (Figure 4, H).
Progressive transformation of germinal centers is characterized by expansion of the cortex by very large macronodules of enlarged secondary follicles with expanded mantle zones that show progressive and multifocal inward migration of mantle zone cells into the germinal center, which leads to germinal center disruption and eventual obliteration (Figure 5, A).
In addition, the absence of proliferation centers and the distribution of neoplastic cells in the mantle zones surrounding germinal centers made this diagnosis highly unlikely.
Nodal and splenic marginal zone lymphomas are neoplasms of small B cells that show an expansion of cells around mantle zones.
Neoplastic follicles appear more ill defined and have indistinct mantle zones
, are devoid of tingible body macrophages, and lack polarity.
Staining for immunoglobulin (Ig) D may be helpful in highlighting mantle zones
, which are attenuated in primary cutaneous follicle center lymphoma as compared with reactive infiltrates.
The growth patterns in lymph nodes in these cases of MCL-B have been described as diffuse, vaguely nodular, vaguely nodular with a focal mantle zone pattern, and as a total mantle zone pattern.
3 82/M MCL-B (LN) Diffuse/focal mantle zone pattern 4 51/M BCL-B (LN) Diffuse and nodular 5 71/F MCL-B (GI tract) .
3] The follicles often have expanded mantle zones
composed of small lymphocytes surrounding abnormal germinal centers, which range in size from medium to barely recognizable.