Synchronous Occurrence of Chronic Myeloid Leukemia and Mantle Cell Lymphoma

The dark side of stemness - the role of hematopoietic stem cells in development of blood malignancies

Hematopoietic stem cells (HSCs) produce all blood cells throughout the life of the organism. However, the high self-renewal and longevity of HSCs predispose them to accumulate mutations. The acquired mutations drive preleukemic clonal hematopoiesis, which is frequent among elderly people. The preleukemic state, although often asymptomatic, increases the risk of blood cancers. Nevertheless, the direct role of preleukemic HSCs is well-evidenced in adult myeloid leukemia (AML), while their contribution to other hematopoietic malignancies remains less understood. Here, we review the evidence supporting the role of preleukemic HSCs in different types of blood cancers, as well as present the alternative models of malignant evolution. Finally, we discuss the clinical importance of preleukemic HSCs in choosing the therapeutic strategies and provide the perspective on further studies on biology of preleukemic HSCs.

Synchronous Occurrence of Splenic Pleomorphic Mantle Cell Lymphoma and Esophageal Adenocarcinoma with Overexpression of BCL1 Protein

Synchronous occurrences of mantle cell lymphoma (MCL), or intermediate lymphocytic lymphoma, and other malignancies are rare. Such cases present diagnostic and especially therapeutic challenges, making them of particular interest to study. We report a case of synchronic MCL and an esophageal tumor in an elderly male patient. Morphologically, the tumors were classified as splenic pleomorphic MCL and adenocarcinoma of the esophagus occurring concurrently. The pleomorphic MCL mimicked diffuse large B cell lymphoma (DLBCL) but lacked larger centroblast- or immunoblast-like cells. Curiously, both tumors overexpressed cyclin D1 by immunohistochemistry. This is an important feature that distinguishes MCL pathologically from two of its closest entities in the differential diagnosis: chronic lymphocytic leukemia and DLBCL, the latter of which mantle cells cannot transform into. The lymphoproliferation revealed IGH/CCND1 translocation by FISH, but the esophageal adenocarcinoma only showed CCND1 aneuploidy without break-apart signals. Since the gastrointestinal (GI) tract is a common site of extranodal involvement by MCL and lymphomatous polyposis can present as GI polyps, adequate care was taken to differentiate the esophageal adenocarcinoma from advanced stagings of MCL, as well as metastatic adenocarcinoma. Despite numerous immunohistochemical stainings studied, only BCL1 was demonstrated to have partial overlap in both tumors. The patient underwent esophagectomy and splenectomy. A subsequent metastatic primary lung squamous cell carcinoma was diagnosed, after which the patient expired. MCL typically presents at an advanced stage and has been deemed incurable with a prognosis of only several years. It is unclear whether the patient succumbed to complications of his MCL or the metastatic squamous cell carcinoma. Furthermore, he was lost to follow-up for a year and only received treatment after his third cancer was diagnosed. We have reviewed previous reports of synchronic mantle cell lymphoma and other solid tumors or hematological malignancies in the literature.

Genetic heterogeneity and prognostic impact of recurrent ANK2 and TP53 mutations in mantle cell lymphoma: a multi-centre cohort study

The molecular features of mantle cell lymphoma (MCL), including its increased incidence, and complex therapies have not been investigated in detail, particularly in East Asian populations. In this study, we performed targeted panel sequencing (TPS) and whole-exome sequencing (WES) to investigate the genetic alterations in Korean MCL patients. We obtained a total of 53 samples from MCL patients from five Korean university hospitals between 2009 and 2016. We identified the recurrently mutated genes such as SYNE1, ATM, KMT2D, CARD11, ANK2, KMT2C, and TP53, which included some known drivers of MCL. The mutational profiles of our cohort indicated genetic heterogeneity. The significantly enriched pathways were mainly involved in gene expression, cell cycle, and programmed cell death. Multivariate analysis revealed that ANK2 mutations impacted the unfavourable overall survival (hazard ratio [HR] 3.126; P = 0.032). Furthermore, TP53 mutations were related to worse progression-free survival (HR 7.813; P = 0.043). Among the recurrently mutated genes with more than 15.0% frequency, discrepancies were found in only 5 genes from 4 patients, suggesting comparability of the TPS to WES in practical laboratory settings. We provide the unbiased genetic landscape that might contribute to MCL pathogenesis and recurrent genes conferring unfavourable outcomes.

A case of primary gastric diffuse large B-cell lymphoma occurring in chronic myeloid leukemia

Chronic myeloid leukemia (CML) and Non-Hodgkin Lymphoma (NHL) are two different origins of hematological malignancies, which rarely occur at the same time. Moreover, NHL secondary to CML is common in T cell lymphoma, while NHL of B cell origin is rare. Since 1999, only 22 cases with B cell lymphoma have been reported, of which 4 cases have diffuse large B-cell lymphoma (DLBCL). The lesions of DLBCL were in lymph node, liver, jejunum, and soft palate. To our knowledge, it has no report for the primary gastric DLBCL (PG-DLBCL) occurring in CML. Here we reported a 63-year-old man of chronic phase (CP) CML associated with PG-DLBCL. The patient was diagnosed with CML nearly eight years ago and was treated with imatinib and nilotinib successively. However, gastroscopy found malignant lesions in the patient’s stomach in March 2018, and the masses were diagnosed as PG-DLBCL. Subsequently, with the treatment of the RCOP + lenalidomide regimen chemotherapy for 3 cycles, the patient achieved nearly complete remission (CR).

Concurrent Diagnosis of Chronic Myeloid Leukemia and Follicular Lymphoma: An Unreported Presentation

Lymphadenopathy in chronic myeloid leukemia (CML) is usually due to extramedullary involvement with accelerated or blast phases of the disease. The occurrence of non-Hodgkin lymphoma (NHL) as a synchronous malignancy with CML is rare. We report a case of a 73-year-old male who presented with dyspnea and right-sided lower extremity edema in the setting of leukocytosis. Bone marrow evaluation indicated a chronic phase chronic myeloid leukemia (CML), confirmed by molecular testing. Imaging of the chest for persistent dyspnea revealed supraclavicular and mediastinal lymphadenopathy. Biopsy of the cervical node showed expanded lymphoid follicles with atypical germinal centers that were positive for CD10, BCL-2, and BCL-6, consistent with follicular lymphoma (FL). Nodal PCR demonstrated clonal IGH and IGK gene rearrangements, and FISH analysis was positive for IGH-BCL-2 fusion. Together, these tests supported the diagnosis of FL. Additionally, the lymph node showed paracortical expansion by maturing pan-hematopoietic elements, no blastic groups, and positive RT-PCR analysis for BCR-ABL1, indicating concomitant involvement by chronic phase-CML. To our knowledge, this is the first reported case of a patient with a concurrent diagnosis of CML and FL.