Most morphologic features in chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) do not reliably predict underlying FISH genetics or immunoglobulin heavy chain variable region somatic mutational status

TP53 Staining in Tissue Samples of Chronic Lymphocytic Lymphoma Cases: An Immunohistochemical Survey of 51 Cases

Objective:

Chronic lymphocytic leukemia (CLL) is the most common lymphoproliferative disease in adults. The aim of this study is to find out if the extent of proliferation centers or the immunohistochemical expression of p53 is related to disease prognosis.

Materials and Methods:

In the scope of this study, 54 biopsy specimens from 51 patients (50 of lymph nodes; the others of spleen, tonsil, orbit, and liver) diagnosed with CLL at the Hacettepe University Department of Pathology in 2000-2013 were reevaluated. The clinical and demographic data of the patients were obtained from our patient database. Biopsy samples were assessed semi-quantitatively for the percentage of proliferation center/total biopsy area (PC/TBA) and an immunohistochemical study was performed on representative blocks of tissues for p53 expression.

Results:

When the patients were divided into two categories according to Rai stage as high and low (stages 0, 1, and 2 vs. stages 3 and 4), it was seen that patients with low Rai stage had a better prognosis than those with high stages (p=0.030). However, there was no statistically significant correlation between overall survival and PC/TBA ratio or p53 expression levels.

Conclusion:

In our cohort, PC/TBA ratio and immunopositivity of p53 did not show correlations with overall survival.

Reassessment of small lymphocytic lymphoma in the era of monoclonal B-cell lymphocytosis

BACKGROUND

In the 2008 World Health Organization classification, small lymphocytic lymphoma is defined as a neoplasm with the tissue morphology and immunophenotype of chronic lymphocytic leukemia, but with absence of leukemia. Minimal criteria of tissue involvement to separate small lymphocytic lymphoma from monoclonal B-cell lymphocytosis have not been defined.

DESIGN AND METHODS

We reviewed the clinicopathological features of 36 patients with extramedullary tissue biopsies containing chronic lymphocytic leukemia-type cells and less than 5×10(9)/L peripheral blood monoclonal B cells. Pathological features (extent and patterns of involvement, architectural preservation, presence of proliferation centers) as well as cytogenetic and radiological findings were examined in relation to clinical outcome.

RESULTS

The biopsies were performed to evaluate lymphadenopathy in 20 patients and for other reasons (most frequently staging of a non-hematologic neoplasm) in 16 patients. At latest follow-up (median 23 months), 21 untreated patients had no or stable lymphadenopathy, 3 had regressed lymphadenopathy, and 12 had developed progressive lymphadenopathy and/or received therapy for chronic lymphocytic leukemia/small lymphocytic lymphoma. Features associated with progression/treatment included lymph nodes 1.5 cm or greater on imaging studies (P=0.01) and presence of proliferation centers in the biopsied tissue (P=0.004). Neither the size nor extent of involvement of the excised lymph node correlated with progression/treatment.

CONCLUSIONS

Our findings suggest that biopsies containing chronic lymphocytic leukemia-type cells, but lacking proliferation centers and with non-enlarged or only slightly enlarged lymph nodes on imaging, represent a very indolent disease that may best be considered a tissue equivalent of monoclonal B-cell lymphocytosis rather than overt small lymphocytic lymphoma. We propose that such cases be designated as tissue involvement by chronic lymphocytic leukemia/small lymphocytic lymphoma-like cells of uncertain significance.

Chronic Lymphocytic Leukemia, Small Lymphocytic Lymphoma, and Monoclonal B-Cell Lymphocytosis

Chronic lymphocytic leukemia (CLL), small lymphocytic lymphoma (SLL), and monoclonal B-cell lymphocytosis (MBL) are clonal proliferations of small, mature B cells. CLL and SLL are considered neoplastic, although they are indolent and many patients with these lymphomas never require treatment. Most MBL cases share immunophenotypic and genetic features with CLL and SLL but have a small burden of clonal cells. This review focuses on the pathologic features of CLL, SLL, and MBL and their differential diagnoses. Guidelines are provided to separate the entities from one another and to avoid pitfalls in distinguishing these entities from other lymphomas and from reactive lymphoid proliferations.