BCL2 gene abnormalities define distinct clinical subsets of follicular lymphoma

AIMS

Follicular lymphoma (FL) arising primarily in the skin has recently been proposed as a distinct entity on the basis of a low incidence of t(14;18)(q32;q21) and bcl-2 expression, with a very high percentage of patients surviving more than 5 years. However, cases of t(14;18)(q32;q21)-positive primary cutaneous FL (PCFL) and examples of t(14;18)(q32;q21)-negative FL at nodal and other extranodal sites, are well documented. The aim of this study was to test the hypothesis that there is a subtype of FL lacking t(14;18)(q32;q21), which preferentially involves certain sites but is not restricted by anatomical location.

METHODS AND RESULTS

A cohort of 47 stage 1 FL was stratified according to the presence or absence of t(14;18)(q32;q21) using conventional cytogenetics, polymerase chain reaction and interphase fluorescence in situ hybridization. Compared with t(14;18)(q32;q21)-positive cases, FL lacking the translocation were less likely to express CD10 or bcl-2 (P<0.01), made up a significantly greater proportion of cases arising at extranodal sites (P<0.001) and had a significantly better overall and disease-specific 5-year survival (P<0.01).

CONCLUSIONS

These results support the concept of a subtype of FL lacking t(14;18)(q32;q21), characterized by low-intensity bcl-2 expression, a predilection for extranodal sites, particularly the skin, and a more favourable outcome than t(14;18)(q32;q21)-positive FL.

Efficacy of screening the intermediate cluster region of the bcl2 gene in follicular lymphomas by PCR

BACKGROUND

The t(14;18) translocation is a common finding in nodal follicular B cell lymphomas and diffuse large B cell lymphomas, and results in the overexpression of the antiapoptotic bcl2 protein. This chromosome rearrangement can be detected by the polymerase chain reaction (PCR), with most breakpoints in the bcl2 gene occurring within either the major breakpoint region (mbr) or the minor cluster region (mcr). However, recent investigations have revealed several breakpoints between these two regions, which cluster 19 kb 3' of mbr in the "intermediate cluster region" (icr).

AIMS/METHODS

To analyse a series of 57 B cell follicular lymphomas known to carry the t(14;18) by PCR with primers directed against all three cluster regions to determine the efficacy of screening the icr site.

RESULTS

Twenty six samples had an mbr rearrangement, four an mcr rearrangement, and three an icr rearrangement.

CONCLUSIONS

These results suggest that screening for icr is at least as efficacious as screening for mcr rearrangements.

Follicular lymphoma with marginal zone differentiation: cytogenetic findings in support of a high-risk variant of follicular lymphoma

AIMS

The pathogenesis and clinical significance of marginal zone differentiation in follicular lymphoma remains to be determined, although genetic alterations are likely to be important determinants of both. We therefore report the cytogenetic findings in three cases of follicular lymphoma with marginal zone differentiation studied by routine karyotyping and in-situ hybridization.

METHODS AND RESULTS

The morphology and immunophenotype of each case was typical of follicular lymphoma displaying marginal zone differentiation. Karyotyping, performed on GTL-banded preparations of cell cultures derived from fresh lymph node tissue, revealed a complex karyotype in all three cases, including t(14;18)(q32;q21) and abnormalities associated with progression and/or transformation of follicular lymphoma. In addition, trisomy 3 was found in one case and translocations between the q27-29 region of chromosome 3 and chromosome 2 in the other two cases; the latter was identified only in subclones derived from less complex stem lines possessing t(14;18). In-situ hybridization, performed on sections cut from routinely processed paraffin-embedded tissue blocks, localized cells possessing these abnormalities of chromosome 3 to both the follicular and marginal zone components of two lymphomas studied in this way.

CONCLUSIONS

Trisomy 3 and alterations involving the q27-29 region of chromosome 3 are implicated in the pathogenesis of de novo marginal zone lymphoma. Their presence in the current cases indicates that they may also be responsible for marginal zone differentiation in follicular lymphoma when cells harbouring these genetic alterations are exposed to the appropriate microenvironment. Our findings are consistent with follicular lymphoma with marginal zone differentiation as a high-risk variant of follicular lymphoma.

Lymphadenopathy and lymph node infarction as a result of gold injections

This report describes a case of lymphadenopathy and lymph node infarction as a consequence of intramuscular gold administered to a patient suffering from rheumatoid arthritis, to highlight this rare association. A 34 year old woman with a four year history of rheumatoid arthritis affecting multiple joints was started on intramuscular gold injections after little response to anti-inflammatory medication. After her sixth injection the patient developed enlarged neck and axillary lymph nodes. Biopsy showed subtotal infarction of a reactive node, confirmed by histochemical, immunohistochemical, and molecular techniques. The patient continued to suffer from rheumatoid arthritis with no evidence of malignant lymphoma after three years. This case provides strong evidence that lymphadenopathy with infarction is a rare complication of gold injections. In such a situation, it is particularly important to exclude a diagnosis of lymphoma, because this is the most common cause of spontaneous lymph node infarction. This can be achieved through awareness of the association, and by the use of ancillary histochemical, immunohistochemical, and molecular techniques on the biopsy material.

Primary cutaneous B-cell lymphoma and Borrelia burgdorferi infection in patients from the Highlands of Scotland

Although a link between primary cutaneous B-cell lymphoma (PCBCL) and Borrelia burgdorferi infection has long been suspected, previous studies have not demonstrated a significant association. The authors looked for evidence of B. burgdorferi in 20 cases of PCBCL from the Scottish Highlands, an area with endemic Lyme disease, and compared their findings with those in 40 control patients (20 undergoing wide reexcision at sites of malignant melanoma and 20 biopsies of inflammatory dermatoses). All studies were performed on formalin-fixed, paraffin-embedded tissues. The cases of PCBCL were classified according to criteria described by the European Organization for Research and Treatment of Cancer Cutaneous Lymphoma Project Group using a combination of morphology, immunohistochemistry, and seminested polymerase chain reaction (PCR) for immunoglobulin heavy chain gene rearrangement. A nested PCR was performed on deoxyribonucleic acid (DNA) extracts from the lymphoma and control cases using primers to a unique conserved region of the B. burgdorferi flagellin gene. B. burgdorferi-specific DNA was detected in seven of 20 lymphoma cases (five of 12 marginal zone lymphomas, one of five primary cutaneous follicle center cell lymphomas, one of three diffuse, large B-cell lymphomas of the leg) and in one melanoma reexcision patient of 40 control subjects. The relationship between B. burgdorferi and PCBCL was significant when compared with the control groups separately (p <0.05) or in combination (p <0.01). These results provide strong evidence to support the concept of B. burgdorferi-driven lymphomagenesis in the skin.

Persistence of two Y chromosomes through meiotic prophase and metaphase I in an XYY man

Studies of spermatogenesis in an XYY male, presenting at a subfertility clinic, confirm the tendency for the germ cells to lose the second Y chromosome but for some XYY cells to reach metaphase I (MI). Light microscope studies of MI revealed the presence of YY bivalents and EM studies of microspread, silver-stained pachytene stages showed 30% of the cells to have two Y chromosomes; 13 out of 16 of these showing a YY synaptonemal complex. Strikingly, the Y axes show only partial synapsis; in no case was synapsis of the long arm heterochromatic regions apparent.

45,X/46,X dic (Y) mosaicism in a phenotypic male

Cytogenetic analysis, confirmed by in situ hybridisation studies, showed a mosaic 45,X/46,X dic (Y) (q12) karyotype in a 14 year old boy who was initially diagnosed as having Noonan's syndrome. He made an early response to recombinant growth hormone; this suggests that this treatment may improve final height.