Wotherspoon criteria combined with B cell clonality analysis by advanced polymerase chain reaction technology discriminates covert gastric marginal zone lymphoma from chronic gastritis

Abstract

Background and aims: Gastric mucosa associated lymphoid tissue lymphoma is a well defined B cell lymphoma yet often impossible to distinguish from severe chronic gastritis on morphological grounds alone. Therefore, it was suggested to use the clonality of the immunoglobulin (Ig) heavy chain (H) genes, as detected by polymerase chain reaction (PCR), as a decisive criterion. However, there is controversy as to whether B cell clonality also exists in chronic gastritis, hence rendering this approach futile at present. Methods: An expert panel re-examined the histology and immunohistochemistry of a total of 97 cases of gastric biopsies, including clearcut marginal zone lymphoma, chronic gastritis, and ambiguous cases, applying the Wotherspoon criteria on the basis of haematoxylin-eosin and CD20 immunostainings. In addition, a new and advanced PCR system for detection of clonal IgH gene rearrangements was independently applied in two institutions in each case. Results: The overall IgH clonality assessments of both institutions were in total agreement. Overt lymphoma (Wotherspoon score 5) was clonal in 24/26 cases. Chronic gastritis (Wotherspoon scores 1 and 2) was not clonal in 52/53 cases; the clonal case being Wotherspoon score 2. Of 18 cases with ambiguous histology (Wotherspoon scores 3 and 4) four were clonal. Conclusions: Using advanced PCR technology, clonal gastritis is extremely rare, if it exists at all. Thus B cell clonality in Wotherspoon 3 and 4 cases is regarded as suitable for definitively diagnosing gastric marginal zone lymphoma.

Lymphoproliferative Disorders of the Gastrointestinal Tract: A Review and Pragmatic Guide to Diagnosis

“…99 This recommendation was supported by another report 100 stating that a combination of the morphologic scoring system and B cell clonality analysis by an advanced PCR method accurately discriminated chronic gastritis from covert gastric marginal zone lymphoma. Polymerase chain reaction was particularly valuable in the interpretation of cases that exhibited an ambiguous score of grade 3 or 4.…”

Comparison of BIOMED-2 Versus Laboratory-Developed Polymerase Chain Reaction Assays for Detecting T-Cell Receptor-γ Gene Rearrangements

“…Others, including the original BIOMED-2 study, have shown that the use of a smaller amount of DNA (80 -300 ng per reaction) from cutaneous and gastric biopsies can be adequate to detect T-cell clonality. 8,28,29 Since the initial validation of BIOMED-2 primers was performed in both fresh/frozen and paraffinembedded tissue using 100 ng of DNA, 15 we used 184 Ϯ 146 ng of DNA (mean Ϯ SD; range: 10 -920 ng) per 25 l reaction based on the size of tissue compared with 500 to 2000 ng per 50 l reaction that is recommended by the manufacturer (InVivoScribe Technologies). It is possible that this lower amount of DNA is optimal for mono-V but not for multi-V PCR amplification of TCR-␥ V11.…”

Extranodal and splenic small B-cell lymphoma

“…Monoclonal population have been found in cases of uncomplicated H. pylori-associated gastritis, 14 although the frequency of detection of such clonal populations increases with an increasing certainty for a diagnosis of lymphoma. 15 Immunophenotypically, the cells of MALT lymphoma show a rather non-descript B-cell phenotype. The cells express pan-B-cell markers (CD19, CD20, CD79a and PAX5) and BCL2.…”