Application of 2016 WHO classification in the diagnosis of paediatric high-grade MYC-negative mature B-cell lymphoma with Burkitt-like morphological features

High-grade B-cell lymphoma with 11q aberrations: A single-center study

High-grade B-cell lymphoma with 11q aberrations (HGBL-11q) has been classified for the first time as a high-grade mature B-cell neoplasm according to the 5th edition of the World Health Organization Classification of Tumors of Hematopoietic and Lymphoid Tissues. HGBL-11q is morphologically and immunohistochemically similar to Burkitt lymphoma (BL) or HGBL; it is characterized by gain in the 11q23.2-11q23.3 region and loss in the 11q24.1-qter region but it lacks MYC translocation. HGBL-11q is a rare tumor, and its exact frequency in Japan remains unclear. In this study, we classified 113 Germinal center B-cell (GCB) type aggressive B-cell lymphomas (BCLs), which were divided into BL, high-grade (HG), and large cell (LC) morphologies. We performed fluorescence in situ hybridization (FISH) to identify 11q aberrations. Nine patients had 11q aberrations (7.96%, 9/113), including six HGBL-11q. The age range was from 8 to 87 years, and all were male. Six out of 14 patients with HG morphology were diagnosed with HGBL-11q (6/14, 42.9%). HGBL-11q has been found to occur primarily in children and young adults but also in middle-aged and older adults. Patients with HG morphology without MYC translocation should undergo FISH for 11q aberrations regardless of age. However, the pathogenesis, clinical findings, and prognosis of HGBL-11q remain unclear. The accumulation of cases with an accurate HGBL-11q diagnosis in daily practice and accurate and detailed data on HGBL-11q will contribute to further understanding of 11q aberrations.

Burkitt-like lymphoma with 11q aberration confirmed by needle biopsy of the liver: A case report

BACKGROUND

Burkitt-like lymphoma with 11q aberration (BLL-11q) is a rare provisional lymphoma, and the majority of cases are usually diagnosed by excisional lymph node biopsy. Here we report a case of BLL-11q diagnosed by needle biopsy of the liver in order to improve further understanding of the disease, reduce misdiagnosis, and identify treatment regimens.

CASE SUMMARY

The patient was a 67-year-old male. He complained of increased frequency of stools for more than one year, periumbilical pain and discomfort exceeding 3 mo. A computed tomography scan suggested an appendiceal malignant tumor with multiple metastases of the peritoneum, omentum, and liver. Needle biopsy of liver nodules showed that the tumor cells were of median size, the shape was consistent, a small number of tumor cells were large, the “starry sky” pattern was evident, and some tissue cells showed multiple apoptotic debris with coarse particles. Immunohistochemistry was positive for CD20, CD10, BCL6, and MYC. The Ki-67 proliferation index was more than 95%. Molecular biological detection indicated a lack of MYC, BCL2 and BCL6 gene rearrangement with 11q aberration. Therefore, the diagnosis was BLL-11q of the liver. After eight courses of chemotherapy, the abdominal and pelvic peritoneal masses and liver nodules had almost disappeared. The patient recovered well after a follow-up period of more than 13 mo.

CONCLUSION

BLL-11q is rare, but patients treated with standard chemotherapy for Burkitt lymphoma can have a good prognosis. Reducing the dose of chemotherapy or developing specific therapies to prevent overtreatment may be considered, but more case studies are needed.

New developments in non-Hodgkin lymphoid malignancies

The revised fourth edition of the World Health Organization (WHO) Classification of Tumours of Haematopoietic and Lymphoid Tissues (2017) reflects significant advances in understanding the biology, genetic basis and behaviour of haematopoietic neoplasms. This review focuses on some of the major changes in B-cell and T-cell non-Hodgkin lymphomas in the 2017 WHO and includes more recent updates. The 2017 WHO saw a shift towards conservatism in the classification of precursor lesions of small B-cell lymphomas such as monoclonal B-cell lymphocytosis, in situ follicular and in situ mantle cell neoplasms. With more widespread use of next generation sequencing (NGS), special entities within follicular lymphoma and mantle cell lymphoma were recognised with recurrent genetic aberrations and unique clinicopathological features. The diagnostic workup of lymphoplasmacytic lymphoma and hairy cell leukaemia has been refined with the discovery of MYD88 L265P and BRAF V600E mutations, respectively, in these entities. Recommendations in the immunohistochemical evaluation of diffuse large B-cell lymphoma include determining cell of origin and expression of MYC and BCL2, so called 'double-expressor' phenotype. EBV-positive large B-cell lymphoma of the elderly has been renamed to recognise its occurrence amongst a wider age group. EBV-positive mucocutaneous ulcer is a newly recognised entity with indolent clinical behaviour that occurs in the setting of immunosuppression. Two lymphomas with recurrent genetic aberrations are newly included provisional entities: Burkitt-like lymphoma with 11q aberration and large B-cell lymphoma with IRF4 rearrangement. Aggressive B-cell lymphomas with MYC, BCL2 and/or BCL6 rearrangements, so called 'double-hit/triple-hit' lymphomas are now a distinct entity. Much progress has been made in understanding intestinal T-cell lymphomas. Enteropathy-associated T-cell lymphoma, type II, is now known to not be associated with coeliac disease and is hence renamed monomorphic epitheliotropic T-cell lymphoma. An indolent clonal T-cell lymphoproliferative disorder of the GI tract is a newly included provisional entity. Angioimmunoblastic T-cell lymphoma and nodal T-cell lymphomas with T-follicular helper phenotype are included in a single broad category, emphasising their shared genetic and phenotypic features. Anaplastic large cell lymphoma, ALK- is upgraded to a definitive entity with subsets carrying recurrent rearrangements in DUSP22 or TP63. Breast implant-associated anaplastic large cell lymphoma is a new provisional entity with indolent behaviour. Finally, cutaneous T-cell proliferations include a new provisional entity, primary cutaneous acral CD8-positive T-cell lymphoma, and reclassification of primary small/medium CD4-positive T-cell lymphoma as lymphoproliferative disorder.