Related Experiment Video
Updated: Jun 26, 2026

Unraveling Key Players of Humoral Immunity: Advanced and Optimized Lymphocyte Isolation Protocol from Murine Peyer's Patches
Published on: November 21, 2018
Histopathological and molecular features of persistent polyclonal B-cell lymphocytosis (PPBL) with progressive
Ilaria Del Giudice1, Stefano A Pileri, Maura Rossi
1Department of Cellular Biotechnologies and Haematology, Division of Haematology, Sapienza University, Rome, Italy.
Abstract:
Five cases of persistent polyclonal B-cell lymphocytosis (PPBL) with progressive splenomegaly are reported; three were splenectomized. BCL2/IGH rearrangements were found in three cases; HLA-DRB1*07 in all. Bone marrow (BM) trephines showed a moderate lymphoid infiltrate with intrasinusoidal distribution resembling a splenic marginal-zone lymphoma. Splenic white pulp revealed an enlargement of the marginal-zone area; red pulp was infiltrated by the same lymphocytes engulfing the sinuses. Splenic and BM B-lymphocytes were CD79a(+)/CD20(+)/IgM(+)/IgD(+)/bcl-2(+)/CD27(+)/DBA.44(-)/CD31(-) and polyclonal by immunophenotype/polymerase chain reaction. PPBL features an expansion of splenic marginal-zone B-lymphocytes, which infiltrate BM sinusoids and circulate in the blood with no evidence of clonality, even in cases with progressive splenomegaly.
Related Concept Videos
Tumor Progression
Colon cancer is one of the best-documented examples of tumor progression. Early mutation in the APC gene in colon cells causes a small growth on the colon wall called a polyp. With time, this polyp grows into a benign, pre-cancerous tumor. Further...
Primary Lymphoid Organs
The red bone marrow is a soft, spongy tissue nestled in the interior of long bones such as the humerus and femur. It is the site...
Secondary Lymphoid Organs
The spleen is a vital organ in the lymphatic system, nestled in the upper left side of the abdomen. It is composed of two primary regions: the red pulp and the white pulp, each having distinct functions. The red pulp performs a significant role in blood filtration. It efficiently purges the blood of old or damaged red blood cells and...