CSF3R T618I mutated chronic myelomonocytic leukemia: A proliferative subtype with a distinct mutational profile.

Chronic myelomonocytic leukemia (CMML) is a clonal myeloid neoplasm characterized by sustained monocytosis and mutations in TET2, ASXL1, SRSF2, SETBP1, NRAS, and KRAS. We describe a rare case of CSF3R T618I mutated CMML that has a proliferative phenotype, myelodysplasia, and additional mutations in ASXL1, SETBP1, KRAS, and PTPN11. Comparing the clinicopathologic features of this case to previously reported cases of CSF3R T618I mutated CMML and CSF3R non-T618I mutated CMML, CSF3R T618I seems to define a unique proliferative subtype of CMML with a distinct mutational profile. The diagnostic challenges and molecular pathogenesis associated with this case are also briefly discussed.

A Combined Biomarker of Bright CD38 and MYC ≥55% Is Highly Predictive of Double-/Triple-Hit High-Grade B-Cell Lymphoma.

OBJECTIVES: Diagnosis of high-grade B-cell lymphoma with MYC and BCL2 or BCL6 rearrangements (double-/triple-hit lymphoma [DTHL]) appears to mandate fluorescence in situ hybridization (FISH) testing for all large B-cell lymphoma (LBCL). Given the low incidence of DTHL, we aimed to identify flow cytometry (FC) and immunohistochemistry (IHC) features of DTHL that could be used to develop an optimal screening strategy. This combined FC-IHC approach has not yet been studied. METHODS: We compared features of 40 cases of DTHL and 39 cases of diffuse LBCL (DLBCL) without MYC rearrangement. RESULTS: Bright CD38 expression (CD38bright) by FC, high MYC expression (≥55%), and double-expressor phenotype by IHC were significantly associated with DTHL. The biomarker combining FC and IHC, CD38bright and/or MYC ≥55%, was superior to FC and IHC markers alone in predicting DTHL. Restricting FISH testing to approximately 25% of LBCL based on CD38brightand/or MYC ≥55% would detect approximately 95% of DTHL-BCL2 and approximately 75% of DHL-BCL6. CONCLUSIONS: Our study demonstrated that the novel biomarker of CD38bright and/or MYC ≥55% is highly predictive of DTHL. Awareness of the advantages and limitations of this screening strategy would facilitate development of a rational diagnostic workflow to provide high-quality patient care.

Lymphomatoid granulomatosis of the central nervous system (CNS-LYG) posing a management challenge.

Isolated central nervous system lymphomatoid granulomatosis (CNS-LYG) can mimic aggressive glioblastomas. We describe a complex presentation of CNS-LYG coexisting with immune thrombocytopenia successfully managed with rituximab and ultra-low-dose radiation therapy.

A Wandering Missionary's Burden: Persistent Fever and Progressive Somnolence in a Returning Traveler.

Human African trypanosomiasis incidence has declined, but diagnosis remains difficult, especially in nonendemic areas. Our patient presented with fever, progressive lethargy, and weight loss for 5 months and had previously traveled to Ghana and Cameroon but had not been to areas with recently reported African trypanosomiasis. Extensive workup was negative, except for lymphocytic pleocytosis in cerebrospinal fluid; ultimately, a bone marrow aspiration revealed necrotizing granulomatous inflammation with 2 trypanosomes discovered on the aspirate smear, consistent with Trypanosoma brucei. The patient was treated with combination nifurtimox and eflornithine with full recovery.

Combined immune checkpoint blockade and radiotherapy induces durable remission in relapsed natural killer/T-cell lymphoma: a case report and review of the literature.

BACKGROUND: Extranodal natural killer/T-cell lymphoma is a rare, aggressive non-Hodgkin lymphoma that is treated upfront mostly with L-asparaginase containing regimens. Relapsed extranodal natural killer/T-cell lymphoma is associated with a poor prognosis, and there is no established standard of care. CASE PRESENTATION: We report the case of a 72 year-old white male with a distant extranasal relapse of extranodal natural killer/T-cell lymphoma that has been managed successfully with a combination of radiation and immune checkpoint blockade with pembrolizumab. Pseudoprogression with new skin and bone lesions on positron emission tomography imaging was encountered during this Caucasian patient's immunotherapy and was successfully managed with supportive care and continuation of immune checkpoint blockade. CONCLUSIONS: The patient has been in complete clinical, radiologic, and molecular remission for close to 3 years and has not had any immune-related adverse effects. Pseudoprogression is a clinical challenge that can be encountered while patients are treated with immunotherapy, and astute clinical acumen is needed for accurate management. We believe this is the longest duration of response to immune checkpoint blockade in relapsed extranodal natural killer/T-cell lymphoma reported to date in literature. There is a strong biologic rationale in combining radiation with immunotherapy. The optimal timing, dose, and duration of radiation combined with immunotherapy in extranodal natural killer/T-cell lymphoma need to be prospectively evaluated.

Lenalidomide-Associated Secondary B-Lymphoblastic Leukemia/Lymphoma-A Unique Entity.

OBJECTIVES: Autologous stem cell transplant with lenalidomide maintenance therapy has greatly improved the relapse-free and overall survival rates of patients with multiple myeloma but also has been associated with an increased risk of secondary B-lymphoblastic leukemia/lymphoma (B-ALL). METHODS: We report a comprehensive review of the clinicopathologic features of 2 patients with multiple myeloma who developed secondary B-ALL during lenalidomide maintenance. RESULTS: Our observations showed that the disease may initially present with subtle clinical, morphologic, and flow-cytometric findings. The flow cytometry findings in such cases may initially mimic an expansion of hematogones with minimal immunophenotypic variation. Both patients achieved complete remission of secondary B-ALL after standard chemotherapy; however, one patient continues to have minimal residual disease, and the other experienced relapse. Next-generation sequencing of the relapse specimen showed numerous, complex abnormalities, suggesting clonal evolution. CONCLUSIONS: Our findings suggest the need for increased awareness and further study of this unique form of secondary B-ALL.

Tumoral Mimics of Subdural Hematomas: Case Report and Review of Diagnostic and Management Strategies in Primary B-Cell Lymphoma of the Subdural Space.

BACKGROUND: Subdural lymphomas are a rare subtype of primary central nervous system lymphomas that can radiographically mimic epidural blood and pose a diagnostic challenge. They can complicate treatment if not preemptively identified. METHODS: We present a case report of a subdural lymphoma that mimicked a compressive subdural hematoma, and we review the PubMed database for similar cases. RESULTS: A 77-year-old woman presented with a transient left facial droop and what appeared to be a subdural hematoma on computed tomography scan. The patient underwent surgery, during which grossly abnormal solid epicortical adherent tissue was noted instead of the expected appearance of a subdural hematoma. An intraoperative biopsy was suggestive of lymphoma, and the surgery was converted to a craniectomy. Pathology confirmed the diagnosis of extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue. The patient underwent radiotherapy with no complications or recurrence. Magnetic resonance imaging demonstrated complete resolution of the mass at 3 months after treatment, at which time the patient underwent a synthetic cranioplasty. Seven case reports of primary dural lymphomas mimicking subdural blood were found, with variable pathologic subclassifications. CONCLUSIONS: Although rare, a primary dural lymphoma can be mistaken for a subdural hematoma on computed tomography scan. The most common subtype is low-grade extranodal marginal zone lymphomas. It is important to keep these diseases in the differential diagnosis, especially when there is incongruence between imaging and the clinical picture, as earlier detection correlates to a stronger therapeutic response.

What Are the Effects of Irreversible Electroporation on a Staphylococcus aureus Rabbit Model of Osteomyelitis?

BACKGROUND: The treatment of osteomyelitis can be challenging because of poor antibiotic penetration into the infected bone and toxicities associated with prolonged antibiotic regimens to control infection. Irreversible electroporation (IRE), a percutaneous image-guided ablation technology in which the targeted delivery of high-voltage electrical pulses permanently damages the cell membrane, has been shown to effectively control bacterial growth in various settings. However, IRE for the management of bone infections has yet to be evaluated. QUESTIONS/PURPOSES: We aimed to evaluate IRE for treating osteomyelitis by assessing (1) the efficacy of IRE to suppress the in vitro growth of a clinical isolate of S. aureus, alone or combined with cefazolin; and (2) the effects of IRE on the in vivo treatment of a rabbit model of osteomyelitis. METHODS: S. aureus strain UAMS-1 expanded in vitro to the log phase was subjected to an electric field of 2700 V/cm, which was delivered in increasing numbers of pulses. Immediately after electroporation, bacteria were plated on agar plates with or without cefazolin. The number of colony-forming units (CFUs) was scored the following day. ANOVA tests were used to analyze in vitro data. In a rabbit osteomyelitis model, we inoculated the same bacterial strain into the radius of adult male New Zealand White rabbits. Three weeks after inoculation, all animals (n = 32) underwent irrigation and débridement, as well as wound culture of the infected forelimb. Then, they were randomly assigned to one of four treatment groups (n = eight per group): untreated control, cefazolin only, IRE only, or combined IRE + cefazolin. Serial radiography was performed to assess disease progression using a semiquantitative grading scale. Bone and soft-tissue specimens from the infected and contralateral forelimbs were collected at 4 weeks after treatment for bacterial isolation and histologic assessment using a semiquantitative scale. RESULTS: The in vitro growth of S. aureus UAMS-1 was impaired by IRE in a pulse-dependent fashion; the number of CFUs/mL was different among seven pulse levels, namely 0, 10, 30, 60, 90, 120, and 150 pulses. With the number of CFUs/mL observed in untreated controls set as 100%, 10 pulses rendered a median of 50.2% (range 47.1% to 58.2%), 30 pulses rendered a median of 2.7% (range 2.5% to 2.8%), 60 pulses rendered a median of 0.014% (range 0.012% to 0.015%), 90 pulses rendered a median of 0.004% (range 0.002% to 0.004%), 120 pulses rendered a median of 0.001% (range 0.001% to 0.001%), and 150 pulses rendered a median of 0.001% (range 0.000% to 0.001%) (Kruskal-Wallis test: p = 0.003). There was an interaction between the effect of the number of pulses and the concentration of cefazolin (two-way ANOVA: F [8, 30] = 17.24; p < 0.001), indicating that combining IRE with cefazolin is more effective than either treatment alone at suppressing the growth of S. aureus UAMS-1. Likewise, the clinical response in the rabbit model (the percentage of animals without detectable residual bacteria in the bone and surrounding soft tissue after treatment) was better in the combination group than in the other groups: control, 12.5% (one of eight animals); IRE only, 12.5% (one of eight animals); cefazolin only, 25% (two of eight animals); and IRE + cefazolin, 75% (six of eight animals) (two-sided Fisher's exact test: p = 0.030). CONCLUSIONS: IRE effectively suppressed the growth of S. aureus UAMS-1 and enhanced the antibacterial effect of cefazolin in in vitro studies. When translated to a rabbit osteomyelitis model, the addition of IRE to conventional parenteral antibiotic treatment produced the strongest response, which supports the in vitro findings. CLINICAL RELEVANCE: Our results show that IRE may improve the results of standard parenteral antibiotic treatment, thus setting the stage for models with larger animals and perhaps trials in humans for validation.

Bright CD38 Expression by Flow Cytometric Analysis Is a Biomarker for Double/Triple Hit Lymphomas with a Moderate Sensitivity and High Specificity.

BACKGROUND: High-grade B-cell lymphomas (HGBCL) with MYC and BCL2 or/and BCL6 rearrangements (R), so-called double/triple-hit lymphomas (DH/THL), are uncommon, clinically aggressive lymphomas that require a prompt diagnosis. We aim to identify flow cytometric immunophenotypic (IP) features of DH/THL that may aid in triaging these cases followed by a timely confirmatory cytogenetic study. METHODS: We compared the IP features of 43 cases of DH/THL to those of 55 cases of single-hit lymphoma (SHL) and 59 cases of diffuse large B-cell lymphoma (DLBCL) without MYC-R (MYCneg DLBCL). We analyzed the expression patterns of CD10, CD19, CD20, CD38, and surface immunoglobulin light chain in lymphoma cells. RESULTS: Bright CD38 expression (CD38bright ) analyzed either qualitatively or semi-quantitatively was more common in DH/THL (56%) than in MYCneg DLBCL (17%) but less common compared to SHL (82%), indicating that CD38bright can serve as a biomarker for DH/THL. Additionally, CD38bright may be a better indicator for predicting DH/THL-BCL2 than DHL-BCL6, and very bright CD38 expression was exclusive to MYC rearranged lymphomas. The expression patterns of other markers were similar among these lymphoma groups. CONCLUSIONS: CD38bright is a biomarker associated with DH/THL with a moderate sensitivity (~50%) and high specificity (~90%). While this marker cannot be used as a screening tool, awareness of this correlation may aid in expediting the diagnosis and prioritizing FISH testing in resource limited settings or situations when samples are limited. Future studies to combine immunohistochemical markers are needed to further enhance the predictive power of CD38bright in diagnosing DH/THL. © 2019 International Clinical Cytometry Society.

Post-transplant Lymphoproliferative Disorder Presented in a Form of Primary Effusion Lymphoma with t (8; 14).

Post-transplant lymphoproliferative disorders (PTLD) are emergent complications of organ transplantation occurring in 2% to 10% of transplanted patients. Epstein-Barr virus (EBV) infections are considered the most important factors for the development of these heterogeneous disorders. Primary effusion lymphoma (PEL) is a lymphoproliferative disorder predominantly described in patients with advanced AIDS and it is almost universally associated with human herpesvirus 8 (HHV8). In rare case, PEL also occurs in HHV8-negative patient, in the setting of hepatitis B and C virus infection. However, all these cases showed pan B-cell markers to be positive. Here, we report a case of PTLD presented as HHV8-negative and HIV-negative primary effusion lymphoma lacking near all lymphoid markers except PAX5 on immunohistochemistry, which created a diagnostic challenge. The diagnosis requires multiple approaches including molecular and genetic tests.

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.

Impact of oncogene rearrangement patterns on outcomes in patients with double-hit non-Hodgkin lymphoma.

BACKGROUND: Double-hit lymphomas (DHLs) are collectively defined as B-cell non-Hodgkin lymphomas harboring rearrangements of MYC as well as B-cell lymphoma 2 (BCL2) and/or B-cell lymphoma 6 (BCL6). To the authors' knowledge, the impact of specific oncogene rearrangements on outcomes of patients with DHL who are treated with immunochemotherapy has not been previously described. METHODS: The authors identified patients whose diagnostic tissue specimens underwent metaphase karyotyping or fluorescence in situ hybridization for MYC as well as both BCL2 and BCL6 rearrangements. Cohorts were defined by the presence (+) or absence (-) of rearrangements: MYC+/BCL2+/BCL6- (BCL2-DHL), MYC+/BCL2-/BCL6+ (BCL6-DHL), and MYC+/BCL2+/BCL6+ (triple-hit lymphoma; THL). RESULTS: A total of 117 patients were included in the current analysis (76 BCL2-DHL patients, 16 BCL6-DHL patients, and 25 THL patients). Compared with patients with BCL2-DHL, those with BCL6-DHL were more likely to be classified as having a non-germinal center cell of origin, presented with extranodal disease, and appeared to achieve higher rates of complete response despite receiving intensive induction therapy less frequently. However, patients with BCL6-DHL experienced a shorter median overall survival if achieving an initial complete response compared with patients with BCL2-DHL. Patients with THL experienced survival outcomes similar to those of patients with BCL2-DHL. CONCLUSIONS: Recognition of the specific oncogene rearrangements may be of prognostic value and potentially guide future therapeutic strategies for patients with DHL.

Impact of induction regimen and stem cell transplantation on outcomes in double-hit lymphoma: a multicenter retrospective analysis.

Patients with double-hit lymphoma (DHL), which is characterized by rearrangements of MYC and either BCL2 or BCL6, face poor prognoses. We conducted a retrospective multicenter study of the impact of baseline clinical factors, induction therapy, and stem cell transplant (SCT) on the outcomes of 311 patients with previously untreated DHL. At median follow-up of 23 months, the median progression-free survival (PFS) and overall survival (OS) rates among all patients were 10.9 and 21.9 months, respectively. Forty percent of patients remain disease-free and 49% remain alive at 2 years. Intensive induction was associated with improved PFS, but not OS, and SCT was not associated with improved OS among patients achieving first complete remission (P = .14). By multivariate analysis, advanced stage, central nervous system involvement, leukocytosis, and LDH >3 times the upper limit of normal were associated with higher risk of death. Correcting for these, intensive induction was associated with improved OS. We developed a novel risk score for DHL, which divides patients into high-, intermediate-, and low-risk groups. In conclusion, a subset of DHL patients may be cured, and some patients may benefit from intensive induction. Further investigations into the roles of SCT and novel agents are needed.

Breast implant-associated anaplastic large cell lymphoma: sensitivity, specificity, and findings of imaging studies in 44 patients.

UNLABELLED: Breast implant-associated anaplastic large cell lymphoma (BIA ALCL) is a newly described clinicopathologic entity. The purpose of this study is to describe the imaging findings of patients with BIA ALCL and determine their sensitivity and specificity in the detection of the presence of an effusion or a mass related to BIA ALCL. A retrospective search was performed of our files as well as of the world literature for patients with pathologically proven BIA ALCL who had been assessed by any imaging study including ultrasound (US), computerized tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET)-CT, as well as mammography. The sensitivity and specificity of each imaging modality in the detection of an effusion or a mass around breast implants was determined. We identified 44 patients who had BIA ALCL and imaging studies performed between 1997 and 2013. The sensitivity for detecting an effusion was 84, 55, 82, and 38 %, and for detecting a mass was 46, 50, 50, and 64 %, by US, CT, MRI, and PET, respectively. The sensitivity of mammography in the detection of an abnormality without distinction of effusion or mass was 73 %, and specificity 50 %. Progression-free survival was worse in patients with an implant-associated mass (p = 0.001). CONCLUSIONS: Current imaging with US, CT, MR, and PET appears suboptimal in the detection of an imaging abnormality associated with BIA ALCL. This under diagnosis may reflect a lack of awareness of this rare entity suggesting the need for better understanding of the spectrum of imaging findings associated with BIA ALCL by breast imagers.

Atypical chronic myeloid leukemia is clinically distinct from unclassifiable myelodysplastic/myeloproliferative neoplasms.

Atypical chronic myeloid leukemia (aCML) is a rare subtype of myelodysplastic/myeloproliferative neoplasm (MDS/MPN) largely defined morphologically. It is, unclear, however, whether aCML-associated features are distinctive enough to allow its separation from unclassifiable MDS/MPN (MDS/MPN-U). To study these 2 rare entities, 134 patient archives were collected from 7 large medical centers, of which 65 (49%) cases were further classified as aCML and the remaining 69 (51%) as MDS/MPN-U. Distinctively, aCML was associated with many adverse features and an inferior overall survival (12.4 vs 21.8 months, P = .004) and AML-free survival (11.2 vs 18.9 months, P = .003). The aCML defining features of leukocytosis and circulating myeloid precursors, but not dysgranulopoiesis, were independent negative predictors. Other factors, such as lactate dehydrogenase, circulating myeloblasts, platelets, and cytogenetics could further stratify MDS/MPN-U but not aCML patient risks. aCML appeared to have more mutated RAS (7/20 [35%] vs 4/29 [14%]) and less JAK2p.V617F (3/42 [7%] vs 10/52 [19%]), but was not statistically significant. Somatic CSF3R T618I (0/54) and CALR (0/30) mutations were not detected either in aCML or MDS/MPN-U. In conclusion, within MDS/MPN, the World Health Organization 2008 criteria for aCML identify a subgroup of patients with features clearly distinct from MDS/MPN-U. The MDS/MPN-U category is heterogeneous, and patient risk can be further stratified by a number of clinicopathological parameters.