(43) Similar to primary cutaneous follicular helper T-cell lymphoma, these cases are composed of follicular helper T-cells that do not display typical centrocyte
morphology; instead, they have round nuclei and relatively abundant cytoplasm.
The marginal zone or centrocyte-like cells are small to medium-sized lymphocytes with variable nuclear membrane irregularities, resembling a centrocyte
. (20) Commonly, the marginal zone cells appear monocytoid with abundant pale-staining cytoplasm and well-delineated borders (Figure 6, C).
Grade 1 or grade 2 follicular lymphoma shows predominantly medium-sized centrocytes
with irregularly cleaved nuclei, centroblasts with noncleaved nuclei, and follicular aggregates on Pap staining.
The histology of FL is characterized by germinal centers of B lymphocytes, predominantly centrocytes
and centroblasts with follicular growth pattern (2,5).
Some lymphoid follicles had a monotonous appearance of their germinal centres, being composed predominately of centrocytes
and only a few centroblasts and lacked tingible body
USG-guided fine-needle aspiration(FNA) taken from the mesenteric lymph nodes showed lymphocyte predominance, few centro blasts,and centrocytes
in the background of lympho glandular bodies and red blood cells without granuloma and epitheloid cells; which is suggestive of reactive lymphadenopathy.
Reactive lymphadenitis was second most common finding with 13(26%) cases showing predominantly small lymphocytes, transforming lymphocytes, centrocytes
, centroblasts, tingible body macrophages and few histiocytes.
Follicular lymphoma (FL) is the most common indolent lymphoma and second most common among non- hodgkin lymphoma (NHL) after diffuse large B-cell lymphoma (DLBCL).1 FL consists of centrocytes
and centroblasts which originate from germinal centre B cell which usually have a partially follicular pattern.2 It occurs in all races, equally among both genders.
Robertus et al., "miRNA profiling of B-cell subsets: specific miRNA profile for germinal center B cells with variation between centroblasts and centrocytes
," Laboratory Investigation, vol.
In the vast majority of cases, there are small to medium sized lymphocytes with irregular nuclear contours, mimicking centrocytes
of a germinal centre.
Through the subsequent stimulation of CD40 by [T.sub.FH] cells, centroblasts differentiate into centrocytes
and move to the light zone .
When naive B-cells (BCL6-, MUM1-, CD 138-) enter the germinal centre, they become centroblasts (BCL6+, MUM1-, CD138-) that subsequently mature into centrocytes
(BCL6+, MUM1-, CD138+) as they undergo immunoglobulin class switching, somatic hypermutation of the immunoglobulin variable genes and mutations of the proto-oncogene BCL6.