Andrés E. Quesada

The absolute percent deviation of IGHV mutation rather than a 98% cut‐off predicts survival of chronic lymphocytic leukaemia patients treated with fludarabine, cyclophosphamide and rituximab

The degree of somatic hypermutation, determined as percent deviation of immunoglobulin heavy chain gene variable region sequence from the germline (IGHV%), is an important prognostic factor in chronic lymphocytic leukaemia (CLL). Currently, a cut‐off of 2% deviation or 98% sequence identity to germline in IGHV sequence is routinely used to dichotomize CLL patients into mutated and unmutated groups. Because dissimilar IGHV% cut‐offs of 1–5% were identified in different studies, we wondered whether no cut‐off should be applied and IGHV% treated as a continuous variable. We analysed the significance of IGHV% in 203 CLL patients enrolled on the original frontline fludarabine, cyclophosphamide and rituximab (FCR) trial with a median of 10 years follow‐up. Using the Cox Proportional Hazard model, IGHV% was identified as a continuous variable that is significantly associated with progression‐free (PFS) and overall survival (OS) (P < 0·001). Furthermore, we validated this finding in 323 patients treated with FCR off‐protocol and in the total cohort (n = 535). Multivariate analysis revealed a continuous trend. Higher IGHV% levels were incrementally associated with favorable PFS and OS in both FCR‐treated cohorts (P < 0·001, both cohorts). Taken together, our data suggest that IGHV% is a continuous variable in CLL patients treated with FCR.

Increased MYC copy number is an independent prognostic factor in patients with diffuse large B-cell lymphoma

Patients with double-hit or triple-hit lymphoma have a significantly worse prognosis compared to patients with diffuse large B-cell lymphoma without MYC rearrangement. However, the prognostic importance of extra copies of MYC, BCL2, or BCL6 has not been fully explored. We studied 663 patients with de novo diffuse large B-cell lymphoma in whom the status of MYC/8q24, BCL2/18q21, and BCL6/3q27 were assessed by fluorescence in situ hybridization. Cases of double or triple extra copy lymphoma were defined by the presence of increased MYC copies and increased BCL2 and/or BCL6 copies or rearrangement. In total, 76 patients with diffuse large B-cell lymphoma had MYC extra copies including 43 cases of double or triple extra copy lymphoma; 105 patients had diffuse large B-cell lymphoma with MYC-R including 56 double- or triple-hit lymphoma; and 482 diffuse large B-cell lymphoma patients had no MYC abnormality (MYC normal). Patients with MYC extra copies, similar to MYC-R, had a worse overall survival compared with MYC normal patients (both P<0.01). The prognosis between patients with MYC extra copies and MYC-R was not statistically significantly different (P=0.086). Cell-of-origin classification failed to correlate with survival in the MYC extra copies group, similar to the MYC-R patient group. Compared with patients with double- or triple-hit lymphoma, patients with double or triple extra copy lymphoma had a higher complete remission rate (P=0.02), but there was no significant statistical difference in overall survival (P=0.089). Intensive induction chemotherapy regimens improved the overall survival of patients with double or triple extra copy lymphoma, but there was no significant improvement of overall survival in patients with MYC-R tumors. Multivariate analysis showed that MYC extra copy in diffuse large B-cell lymphoma is an independent poor prognostic factor, similar to MYC rearrangement.

Analysis of class I and II histone deacetylase gene expression in human leukemia

Histone deacetylase (HDAC) inhibitors are well-characterized anti-leukemia agents and HDAC gene expression deregulation has been reported in various types of cancers. This study sought to characterize HDAC gene expression patterns in several types of leukemia. To do so, a systematic study was performed of the mRNA expression of all drug-targetable HDACs for which reagents were available. This was done by real-time PCR in 24 leukemia cell lines and 39 leukemia patients, which included AML, MDS and CLL patients, some of whom received HDAC inhibitor treatment. Among the samples analyzed, there was no discernible pattern in HDAC expression. HDAC expression was generally increased in CLL patients, except for HDAC2 and HDAC4. HDAC expression was also generally increased in VPA-treated MOLT4 cells. However, this increased expression was not seen in AML patients treated with vorinostat. In summary, increased HDAC expression was noted in CLL patients in general, but the HDAC expression patterns in myeloid malignancies appear to be heterogeneous, which implies that the role of HDACs in leukemia may be related to global expression or protein function rather than specific expression patterns.

Clinicopathologic Features and Prognostic Impact of Lymph Node Involvement in Patients with Breast Implant-associated Anaplastic Large Cell Lymphoma

Breast implant-associated anaplastic large cell lymphoma (BI-ALCL) is a rare T-cell lymphoma that arises around breast implants. Most patients manifest with periprosthetic effusion, whereas a subset of patients develops a tumor mass or lymph node involvement (LNI). The aim of this study is to describe the pathologic features of lymph nodes from patients with BI-ALCL and assess the prognostic impact of LNI. Clinical findings and histopathologic features of lymph nodes were assessed in 70 patients with BI-ALCL. LNI was defined by the histologic demonstration of ALCL in lymph nodes. Fourteen (20%) patients with BI-ALCL had LNI, all lymph nodes involved were regional, the most frequent were axillary (93%). The pattern of involvement was sinusoidal in 13 (92.9%) cases, often associated with perifollicular, interfollicular, and diffuse patterns. Two cases had Hodgkin-like patterns. The 5-year overall survival was 75% for patients with LNI and 97.9% for patients without LNI at presentation (P=0.003). Six of 49 (12.2%) of patients with tumor confined by the capsule had LNI, compared with LNI in 8/21 (38%) patients with tumor beyond the capsule. Most patients with LNI achieved complete remission after various therapeutic approaches. Two of 14 (14.3%) patients with LNI died of disease compared with 0/56 (0%) patients without LNI. Twenty percent of patients with BI-ALCL had LNI by lymphoma, most often in a sinusoidal pattern. We conclude that BI-ALCL beyond capsule is associated with a higher risk of LNI. Involvement of lymph nodes was associated with decreased overall survival. Misdiagnosis as Hodgkin lymphoma is a pitfall.

Prognostic significance of cytogenetic abnormalities in T‐cell prolymphocytic leukemia

T‐cell prolymphocytic leukemia (T‐PLL) is an aggressive mature T‐cell neoplasm. The most common cytogenetic abnormality associated with T‐PLL is inv(14)(q11.2q32) involving TCL1, but other abnormalities also have been reported. In this study, we correlated cytogenetic abnormalities with clinical outcome in 97 T‐PLL patients, including 66 men and 31 women with a median age of 63 years (range, 34‐81). Twenty‐seven patients had a normal karyotype (NK), one had two chromosomal aberrations, and 69 had a complex karyotype (CK). Patients with a CK had poorer overall survival (OS) than patients with a NK (P = .0016). In the CK group, the most common aberrations involved 14q (n = 45) and 8q (n = 38). Additional deletions of chromosomes 17p, 11q, 6q, 12p, 13q were observed frequently. No individual cytogenetic abnormality impacted OS. Patients with ≥5 aberrations had an OS of 11 months versus 22 months in patients with <5 aberrations (P = 0.0132). Fluorescence in situ hybridization for TCL1 successfully performed in 27 cases showed rearrangement in 8/10 (80%) NK versus 16/17 (94%) CK cases. OS of patients with TCL1 rearrangement and/or 14q aberrations was not significantly different from patients without TCL1 rearrangement and 14q aberrations (P = .3467). Patients with refractory disease showed worse OS in both the NK and CK groups (P = .0014 and P < .0001, respectively), compared with patients who achieved remission but then relapsed. Stem cell transplantation did not appear to improve OS regardless of karyotype complexity. In conclusion, patients with T‐PLL often have a CK which is a poor prognostic factor, particularly in patients with ≥5 cytogenetic aberrations.

Mixed phenotype acute leukemia contains heterogeneous genetic mutations by next-generation sequencing

Mixed phenotype acute leukemia (MPAL) is an uncommon manifestation of acute leukemia. The aim of this study is to further characterize the genetic landscape of de novo cases of MPAL that fulfill the 2016 World Health Organization (WHO) classification criteria for this entity. We identified 14 cases examined by next generation sequencing (NGS) using 28 (n = 10), 53 (n = 3) or 81 (n = 1) gene panels: 7 cases with a B-cell/myeloid (B/My) immunophenotype, 6 T-cell/myeloid (T/My) immunophenotype, and 1 B-cell/T-cell (B/T) immunophenotype. A total of 25 distinct mutations were identified in 15 different genes in 9/14 (64%) patients. FLT3-ITD was the only recurrent mutation in 2 patients. B/My MPAL cases less commonly harbored mutations compared with T/My MPAL cases (43% vs. 100%, p = 0.07). In contrast, B/My MPALs more commonly showed a complex karyotype compared to T/My MPALs (71% vs. 17%, p = 0.1). With NGS and karyotype combined, most (93%) MPAL cases had mutations or cytogenetic abnormalities. With a median follow-up of 12.5 months, there were no significant differences in median overall survival (OS) between patients with B/My or T/My MPAL (17.8 and 6.5 months, respectively, p = 0.81) or between patients with MPAL with versus without gene mutations (6.5 and 13.3 months, respectively, p = 0.86). Our data suggest that the distinguishing cases of MPAL according to immunophenotype has value because the underlying mechanisms of leukemogenesis might differ between B/My and T/My MPAL.

Chronic Myelomonocytic Leukemia with Fibrosis Is a Distinct Disease Subset with Myeloproliferative Features and Frequent JAK2 p.V617F Mutations

A subset of patients with chronic myelomonocytic leukemia (CMML) presents with significance myelofibrosis. In myelodysplastic syndromes, significant myelofibrosis has been associated with adverse outcomes and p53 dysregulation. However, in CMML the clinical and molecular correlates of significant myelofibrosis at presentation remain poorly understood. From a cohort of 651 CMML patients, we identified retrospectively 20 (3.1%) cases with moderate to severe reticulin fibrosis (CMML-F) detected at diagnosis, and we compared them to CMML patients without fibrosis (n=631) seen during the same period. Patients with CMML-F had a median age of 69.8 years (range, 24.8 to 91.2 y) and most (13; 65%) were men. Patients with CMML-F differed significantly from other CMML patients across the following parameters: white blood count, absolute monocyte count, serum lactate dehydrogenase level, splenomegaly, and bone marrow blast percentage. Notably, the frequency of JAK2 p.V617F mutation was higher in CMML-F patients compared with other CMML patients (P<0.001). Most CMML-F patients (12/20; 60%) had myeloproliferative CMML. Dysregulation of p53 was uncommon in CMML-F. CMML-F patients tended to have a shorter median overall survival compared with other CMML patients (P=0.079). Multivariate analysis using the Cox proportional hazards model showed an independent association between CMML-F and overall survival (P=0.047). In summary, unlike typical CMML, CMML-F is commonly associated with JAK2 p.V617F. The high frequency of myeloproliferative features and JAK2 p.V617F mutation, and the low frequency of p53 dysregulation, suggest that fibrosis in the context of CMML has a different pathogenesis from that previously reported in myelodysplastic syndrome.

Classical Hodgkin lymphoma arising in a patient with chronic lymphocytic leukemia (Richter syndrome)

![Figure][1] A 66-year-old man was diagnosed with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) in 2006, observed until 2011, and then treated with fludarabine/cyclophosphamide/rituximab followed by ibrutinib/venetoclax without complete remission. In 2017, an abdominal

Burkitt lymphoma presenting as a mass in the thyroid gland: a clinicopathologic study of 7 cases and review of the literature

Burkitt lymphoma presenting in the thyroid gland is rare, and only a few cases have been reported. We retrospectively reviewed 7 patients diagnosed with Burkitt lymphoma of the thyroid gland between 2000 and 2015. There were 4 men and 3 women with a median age of 41 years (range, 19-49 years). All patients presented with a rapidly growing neck mass associated with upper airway compression in 5 (71%) patients. Two patients presented with localized (stage I/II) and 5 patients with disseminated (stage III/IV) disease. All cases showed morphologic and immunophenotypic features of Burkitt lymphoma with MYC rearrangement in all 5 cases tested. One case showed evidence of concurrent Hashimoto thyroiditis. Six of 7 patients were treated primarily with rituximab, hyperfractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone. One patient was treated primarily with dose-adjusted rituximab, etoposide, prednisolone, vincristine, and cyclophosphamide. At the end of the study period, 5 patients were alive: 4 in complete remission and 1 with persistent disease. Two patients died with persistent disease (median follow-up, 25 months; range, 12-361 months). We conclude that Burkitt lymphoma of the thyroid gland shows clinicopathologic features similar to sporadic Burkitt lymphoma at other anatomic sites, but patients present at an older median age. The clinical course is aggressive with a high frequency of disseminated disease at diagnosis; however, a subset of patients responds well to aggressive chemotherapy.

Phosphorylated STAT3 expression in hematopoietic stem cell transplant-associated large granular lymphocytic leukemia

Phosphorylated STAT3 expression in hematopoietic stem cell transplant-associated large granular lymphocytic leukemia