The value of thymus and activation related chemokine immunohistochemistry in classic Hodgkin lymphoma diagnostics.

AIMS: Classic Hodgkin lymphoma (cHL) should be distinguished from its wide variety of histological mimics, including reactive conditions and mature B and T cell neoplasms. Thymus and activation-related chemokine (TARC) is produced in extremely high quantities by the Hodgkin/Reed-Sternberg (HRS) tumour cells and is largely responsible for the attraction of CD4+ T cells into the cHL tumour micro-environment. In the current study we evaluated the diagnostic potential of TARC immunohistochemistry in daily practice in a tertiary referral centre in the Netherlands. METHODS AND RESULTS: A total of 383 cases, approximately half of which were cHL mimics, were prospectively evaluated in the period from June 2014 to November 2020. In 190 cHL cases, 92% were TARC-positive and the majority of cases showed strong and highly specific staining in all HRS cells (77%). In most cases, TARC could discriminate between nodular lymphocyte-predominant and lymphocyte-rich Hodgkin lymphoma. HRS-like cells in mature lymphoid neoplasms were rarely positive (6.4%) and there was no TARC staining at all in 64 reactive lymphadenopathies. CONCLUSIONS: TARC immunohistochemistry has great value in differentiating between cHL and its mimics, including nodular lymphocyte-predominant Hodgkin lymphoma, reactive lymphadenopathies and mature lymphoid neoplasms with HRS-like cells.

18F-FDG PET/CT in the Diagnostic and Treatment Evaluation of Pediatric Posttransplant Lymphoproliferative Disorders.

We aimed to evaluate the diagnostic performance of 18F-FDG PET/CT for the detection of posttransplantation lymphoproliferative disorder (PTLD) in a pediatric population and explore its feasibility during response assessment. Methods: This retrospective study included 28 pediatric transplant recipients who underwent a total of 32 18F-FDG PET/CT scans due to clinical suspicion of PTLD within an 8-y period. Pathology reports and 2 y of follow-up were used as the reference standard. Twenty-one response assessment 18F-FDG PET/CT scans were reevaluated according to the Lugano criteria. Results: The diagnosis of PTLD was established in 14 patients (49%). Sensitivity, specificity, positive predictive value, and negative predictive value of 18F-FDG PET/CT for the detection of PTLD in children with a clinical suspicion of this disease were 50% (7/14), 100% (18/18), 100% (7/7), and 72% (18/25), respectively. False-negative results occurred in patients with PTLD in the Waldeyer's ring, cervical lymph nodes, or small bowel with either nondestructive or polymorphic PTLD. Two of 5 interim 18F-FDG PET/CT scans and 3 of 9 end-of-treatment 18F-FDG PET/CT scans were false-positive. Conclusion:18F-FDG PET/CT had good specificity and positive predictive value but low to moderate sensitivity and negative predictive value for the detection of PTLD in a 28-pediatric-patient cohort with a clinical suspicion of this disease. False-negative results were confirmed in the Waldeyer's ring, cervical lymph nodes, and small bowel with either nondestructive or polymorphic PTLD subtypes. 18F-FDG PET/CT appears to have a limited role in the response assessment setting of pediatric PTLD, given the observed high proportions of false-positives both at interim and at end-of-treatment evaluations.

Tubulopapillary adrenocortical adenoma in a patient with familial adenomatous polyposis: a morphologic, ultrastructural, and molecular study.

Patients with familial adenomatous polyposis have a higher incidence for developing adrenal neoplasms, most of which are nonfunctioning with conventional histologic appearance. We report a patient with a history of multiple colon polyps who developed an adrenocortical adenoma with unusual morphology. The tumor showed a tubulopapillary architecture and plasmacytoid cytomorphology that were distinct from conventional adrenocortical adenomas. ß-Catenin stain showed aberrant nuclear positivity in the tumor, suggesting an altered ß-catenin-related pathway. The unusual morphology prompted molecular characterization, and sequencing demonstrated the patient to be germline heterozygous for a 5-base-pair APC deletion at codon 1309 with loss of heterozygosity in the tumor. Our study provides further evidence of genetic predisposition to extraintestinal tumors in the familial adenomatous polyposis population.

EpCAM Expression in Lymph Node Metastases of Urothelial Cell Carcinoma of the Bladder: A Pilot Study.

In this retrospective pilot study, the feasibility of the epithelial cell adhesion molecule (EpCAM) as an imaging target for lymph node (LN) metastatic disease of urothelial cell carcinoma (UCC) of the bladder was investigated. LN metastases and LNs without metastases of patients who underwent pelvic lymph node dissection because of muscle invasive bladder cancer (MIBC) were used. Primary tumors of the same patients were used from cystectomy specimen, transurethral resections, and biopsies. A pathologist, blinded to clinical data, scored EpCAM immunoreactivity. This method determines a total immunostaining score, which is the product of a proportion score and an intensity score. EpCAM expression was observed in 19/20 (95%) LNs with UCC metastases and in 11/12 (92%) of the primary tumors. EpCAM expression was absent in 14/14 (100%) LNs without metastases. Median EpCAM expression (TIS) in LN metastases was 5 (IQR 2.0-8.0) and in the primary tumors 6 (IQR 2.3-11.0). Based on the absence of staining in LNs without metastases, EpCAM show high tumor distinctiveness. EpCAM seems to be a feasible imaging target in LN metastases of UCC of the bladder. Pre- and perioperative visualization of these metastases will improve disease staging and improve the complete resection of LN metastases in MIBC.

MYC expression and translocation analyses in low-grade and transformed follicular lymphoma.

AIMS: Low-grade follicular lymphoma (FL) (grade 1/2, FL1/2) has an annual risk of transformation of ≈3%, which is associated with aberrations in CDKN2A/B, TP53, and MYC. As in diffuse large B-cell lymphoma, high MYC expression in transformed FL (tFL) might predict a MYC breakpoint. METHODS AND RESULTS: We quantified MYC expression by immunohistochemistry and digital analysis in 41 paired biopsies from 20 patients with FL1/2 with subsequent transformation and in four isolated biopsies of tFL. As controls, 28 biopsies of FL1/2 without transformation (median follow-up of 105 months) and nine biopsies of FL3A/B were analysed. In the 20 FL1/2-tFL pairs, MYC expression was significantly higher in tFL than in the initial FL1/2 biopsies (median 54% versus 6%; 7% in FL3A, and 35% in FL3B). MYC breaks (MYC-R) were detected in eight of 21 (38%) tFLs analysed by fluorescence in-situ hybridization (FISH), with a median MYC score of 86%. In two of the analysed tFL cases, the translocation was already detected in antecedent FL1/2. MYC partners were immunoglobulin (IG) loci in three of eight cases (one IGL, one IGH, and one IGK) and non-IG in five of eight cases (two PAX5, one BCL6, and two unknown). Of the eight MYC-R+ cases, six were BCL2+/MYC+ double-hit, one was BCL2+/BCL6+/MYC+ triple-hit, and one was MYC+ single-hit. All three IG-MYC+ cases showed a MYC expression level of >85%, whereas the five cases with a non-IG MYC partner had a wider range of expression (median 68%, range 13-86%). Among the 13 MYC-R- tFLs, two groups with almost dichotomous MYC expression could be observed (three cases showed ≥90% MYC expression), suggesting alternative mechanisms of MYC activation. CONCLUSIONS: we show an increase in MYC expression from FL1/2 to tFL. MYC breakpoints were present in ≈40% of the cases, which is markedly higher than in de novo DLBCL. MYC expression was uniformly high in cases with an IG-MYC translocation but much more heterogeneous and in part independent of the presence of a MYC break in non-IG-MYC and MYC-negative cases.

EpCAM Expression in Lymph Node and Bone Metastases of Prostate Carcinoma: A Pilot Study.

There is an urgent need for new imaging modalities in prostate carcinoma staging. A non-invasive modality that can assess lymph node and bone metastases simultaneously is preferred. Epithelial cell adhesion molecule (EpCAM) is a membranous protein of interest as an imaging target since it is overexpressed in prostatic carcinoma compared with benign prostate epithelium and compared with stroma. However, EpCAM expression in lymph node metastases is sparsely available in the literature and EpCAM expression in bone metastases is yet unknown. The current study evaluates the expression of EpCAM in prostate carcinoma lymph nodes, in matched normal lymph nodes, in prostate carcinoma bone metastases, and in normal bone by immunohistochemistry. EpCAM was expressed in 100% of lymph node metastases (21 out of 21), in 0% of normal lymph nodes (0 out of 21), in 95% of bone metastases (19 out of 20), and in 0% of normal bone (0 out of 14). Based on these results, EpCAM may be a feasible imaging target in prostate carcinoma lymph node and bone metastases. Prospective clinical trials are needed to confirm current results. Preoperative visualization of prostate carcinoma metastases will improve disease staging and will prevent unnecessary invasive surgery.

Paediatric nodal marginal zone B-cell lymphadenopathy of the neck: a Haemophilus influenzae-driven immune disorder?

Many hyperplasias and lymphomas of marginal zone B-cells are associated with infection. We identified six children and one adolescent with cervical lymphadenopathy showing prominent polyclonal nodal marginal zone hyperplasia (pNMZH) and four adolescents with monoclonal paediatric nodal marginal zone lymphoma (pNMZL). The clonality status was assessed using BIOMED-2-IG PCR analysis. Haemophilus influenzae was identified in all six cases of pNMZH that could be tested by direct culture (N = 3) or a very sensitive PCR for the H. influenzae gyrase gene in frozen materials (N = 5). H. influenzae was not detected in three pNMZLs and 28 non-specific reactive cervical lymph nodes of age-matched controls, except for a single control node that was obtained during oropharyngeal surgery for a cleft palate showing very low copy numbers of H. influenzae. pNMZH patients were younger than pNMZL patients (median age 12 versus 21 years). pNMZH showed a prominent nodular appearance with variable fibrosis without acute inflammation. Within the nodules, the expanded germinal centres and variably sized marginal zones were colonized by activated B-cells with weak expression of IgD and lack of CD10 and/or BCL6 expression. Some areas showed skewed light chain expression in plasma cells (4/5 cases lambda). In four cases tested, this was confirmed by flow cytometry for surface Ig (3/4 cases lambda). In contrast, pNMZL showed more extensive expansion of marginal zones by centrocytoid cells and often expression of BCL2 protein. Several H. influenzae strains are known to interact with the constant part of IgD on human B-cells, leading to their polyclonal proliferation and activation. We speculate that in vivo stimulation of IgD+ marginal zone B-cells by this bacterium may be implicated in this particular lymphadenopathy that should be distinguished from monoclonal pNMZL.

CXCR4 inhibition enhances radiosensitivity, while inducing cancer cell mobilization in a prostate cancer mouse model.

Preclinical studies show that stroma affects sensitivity of prostate cancer cells via activation of the CXCR4/CXCL12 pathway. Here we studied the effect of CXCR4 inhibition combined with irradiation in prostate cancer cells. In an in vitro co-culture with stromal cells, the CXCR4 inhibitor AMD3100 sensitized prostate cancer cell lines PC3-Luc and LNCaP to irradiation (P = 0.04). Tumor growth and metastasis were evaluated in mice xenografted with luciferase-expressing PC3 cells that received 5 Gy irradiation weekly ± 3.5 mg/kg AMD3100 daily intraperitoneally. The irradiated xenografts showed higher CXCR4 (P = 0.006) and CXCL12 (P = 0.01) expression, compared to controls. AMD3100 sensitized the xenografts to irradiation at the fourth week of treatment (P = 0.02). However AMD3100 also mobilized tumor cells at days 14 and 21 (P < 0.0001), as shown by bioluminescent imaging. In conclusion, AMD3100 transiently enhances prostate cancer radiosensitivity, but induces cancer cell mobilization.

Epstein-Barr virus, the germinal centre and the development of Hodgkin's lymphoma.

The relationship between Epstein-Barr virus (EBV) and the germinal centre (GC) of the asymptomatic host remains an enigma. The occasional appearance of EBV-positive germinal centres in some patients, particularly those with a history of immunosuppression, suggests that EBV numbers in the GC are subject to immune control. The relationship, if any, between lymphoid hyperplasia with EBV-positive germinal centres and subsequent or concurrent lymphomagenesis remains to be clarified. As far as the development of EBV-associated Hodgkin's lymphoma is concerned, the suppression of virus replication, mediated by LMP1 on the one hand, and the loss of B-cell receptor signalling on the other, appears to be an important pathogenic mechanism. A further important emerging concept is that alterations in the microenvironment of the EBV-infected B-cell may be important for lymphomagenesis.

PSMA, EpCAM, VEGF and GRPR as imaging targets in locally recurrent prostate cancer after radiotherapy.

In this retrospective pilot study, the expression of the prostate-specific membrane antigen (PSMA), the epithelial cell adhesion molecule (EpCAM), the vascular endothelial growth factor (VEGF) and the gastrin-releasing peptide receptor (GRPR) in locally recurrent prostate cancer after brachytherapy or external beam radiotherapy (EBRT) was investigated, and their adequacy for targeted imaging was analyzed. Prostate cancer specimens were collected of 17 patients who underwent salvage prostatectomy because of locally recurrent prostate cancer after brachytherapy or EBRT. Immunohistochemistry was performed. A pathologist scored the immunoreactivity in prostate cancer and stroma. Staining for PSMA was seen in 100% (17/17), EpCAM in 82.3% (14/17), VEGF in 82.3% (14/17) and GRPR in 100% (17/17) of prostate cancer specimens. Staining for PSMA, EpCAM and VEGF was seen in 0% (0/17) and for GRPR in 100% (17/17) of the specimens' stromal compartments. In 11.8% (2/17) of cases, the GRPR staining intensity of prostate cancer was higher than stroma, while in 88.2% (15/17), the staining was equal. Based on the absence of stromal staining, PSMA, EpCAM and VEGF show high tumor distinctiveness. Therefore, PSMA, EpCAM and VEGF can be used as targets for the bioimaging of recurrent prostate cancer after EBRT to exclude metastatic disease and/or to plan local salvage therapy.

Application of (99m)Technetium-HYNIC(tricine/TPPTS)-Aca-Bombesin(7-14) SPECT/CT in prostate cancer patients: a first-in-man study.

RATIONALE: The peptide bombesin (BBN) and its derivatives exhibit high binding affinity for the gastrin-releasing peptide receptor (GRPR), which is highly expressed in prostate cancer. We used the BBN-based radiopharmaceutical (99m)Technetium-HYNIC(tricine/TPPTS)-Aca-Bombesin(7-14) ((99m)Tc-HABBN) to perform a first-in-man clinical pilot study to evaluate the feasibility of (99m)Tc-HABBN SPECT/CT for detection of prostate cancer in patients. METHODS: Eight patients with biopsy-proven prostate cancer who were scheduled for either radical prostatectomy or external beam radiotherapy underwent (99m)Tc-HABBN scintigraphy and SPECT/CT prior to treatment. Serial blood samples were taken to assess blood radioactivity and to determine in vivo metabolic stability. Clinical parameters were measured and reported side effects, if present, were recorded. Prostate cancer specimens of all patients were immunohistochemically stained for GRPR. RESULTS: (99m)Tc-HABBN was synthesized with high radiochemical yield, purity and specific activity. There were no significant changes in clinical parameters, and there were no adverse or subjective side effects. Low metabolic stability was observed, as less than 20% of (99m)Tc-HABBN was intact after 30 min. Immunohistochemical staining for GRPR was observed in the prostate cancer specimens in all patients. (99m)Tc-HABBN scintigraphy and SPECT/CT did not detect prostate cancer in patients with proven disease. CONCLUSIONS: (99m)Tc-HABBN SPECT/CT for visualization of prostate cancer is safe but hampered by an unexpected low in vivo metabolic stability in man. The difference between the excellent in vitro stability of (99m)Tc-HABBN in human serum samples determined in our previous study regarding (99m)Tc-HABBN and the low in vivo metabolic stability determined in this study, is striking. This issue warrants further study of peptide-based radiopharmaceuticals.

A single center analysis of nucleophosmin in acute myeloid leukemia: value of combining immunohistochemistry with molecular mutation analysis.

Mutations of nucleophosmin 1 are frequently found in acute myeloid leukemia and lead to aberrant cytoplasmic accumulation of nucleophosmin protein. Immunohistochemical staining is therefore recommended as the technique of choice in front-line screening. In this study, we assessed the sensitivity and specificity of immunohistochemistry on formalin-fixed bone marrow biopsies compared with gold standard molecular analysis to predict nucleophosmin 1 mutation status in 119 patients with acute myeloid leukemia. Discrepant cases were further characterized by gene expression analyses and fluorescence in situ hybridization. A large overlap between both methods was observed. Nevertheless, nine patients demonstrated discordant results at initial screening. Five cases demonstrated nuclear staining of nucleophosmin 1 by immunohistochemistry, but a nucleophosmin 1 mutation by molecular analysis. In two cases this could be attributed to technical issues and in three cases minor subpopulations of myeloblasts had not been discovered initially. All tested cases exhibited the characteristic nucleophosmin-mutated gene expression pattern. Four cases had cytoplasmic nucleophosmin 1 staining and a nucleophosmin-mutated gene expression pattern without a detectable nucleophosmin 1 mutation. In two of these cases we found the chromosomal translocation t(3;5)(q25;q35) encoding the NPM-MLF1 fusion protein. In the other discrepant cases the aberrant cytoplasmic nucleophosmin staining and gene expression could not be explained. In total six patients (5%) had true discordant results between immunohistochemistry and mutation analysis. We conclude that cytoplasmic nucleophosmin localization is not always caused by a conventional nucleophosmin 1 mutation and that in the screening for nucleophosmin 1 abnormalities, most information will be obtained by combining immunohistochemistry with molecular analysis.

High acute myeloid leukemia derived VEGFA levels are associated with a specific vascular morphology in the leukemic bone marrow.

BACKGROUND: Acute Myeloid Leukemia (AML) bone marrow biopsies at diagnosis display enhanced angiogenesis and increased VEGFA expression. In a xenograft mouse model it was described that availability of free VEGFA versus bound VEGFA is related to different vascular morphology. In this study we investigate the relationship between vascular morphology within AML bone marrow biopsies and AML derived VEGFA levels. METHODS: Vessel count and surface area (Chalkley count) were calculated in AML bone marrow biopsies at diagnosis (n = 32), at remission (n = 8) and Normal Bone Marrow (n = 32) using immunohistochemical staining for FVIII, CD31, CTIV, SMA and VEGFA. VEGFA protein levels were measured. RESULTS: High vessel count was associated with an immature vessel status. Combining vessel count and Chalkley count different vessel morphology patterns were quantified within AML bone marrow biopsies. Three different subgroups could be distinguished. The subgroup (37.5% of the samples) exhibiting a high vessel count and vessels with predominantly large lumen (normal Chalkley count) was associated with high secreted VEGFA protein levels. CONCLUSION: Different vasculature patterns are seen in AML bone marrow biopsies, defined by combining number and size of vessel. These quantified morphology patterns, combined with VEGFA levels, might be of value in the success of VEGF/VEGFR-signaling interference approaches.

Efficacy of single-agent lenalidomide in patients with JAK2 (V617F) mutated refractory anemia with ring sideroblasts and thrombocytosis.

Patients with refractory anemia with ring sideroblasts and thrombocytosis (RARS-T) are difficult to treat because the cytoreductive treatment might be beneficial for the thrombocytosis component but harmful for the RARS component. As lenalidomide has shown to be efficacious in both myelodysplastic syndromes and myeloproliferative neoplasms, we have treated 2 RARS-T patients, who were transfusion dependent, with lenalidomide. We report the results of lenalidomide treatment in these patients and show that lenalidomide has clinical activity in this rare disorder. Both patients became transfusion independent, and 1 of the patients attained indeed a complete molecular remission.

Specific expression of miR-17-5p and miR-127 in testicular and central nervous system diffuse large B-cell lymphoma.

Recent studies have shown that certain non-coding short RNAs, called miRNAs, play an important role in diffuse large B-cell lymphomas. Patients with diffuse large B-cell lymphoma have great diversity in both clinical characteristics, site of presentation and outcome. The aim of our study is to validate the differential expression in germinal center and non-germinal center diffuse large B-cell lymphoma,s and to study to the extent to which the primary site of differentiation is associated with the miRNA expression profile. We studied 50 cases of de novo diffuse large B-cell lymphoma for the expression of 15 miRNAs (miR-15a, miR-15b, miR-16, miR-17-3p, miR-17-5p, miR-18a, miR-19a, miR-19b, miR-20a, miR-21, miR-92, miR-127, miR-155, miR-181a and miR-221). Apart from 19 nodal cases without extranodal dissemination (stages I and II), we selected two groups with unambiguous stages I and II extranodal presentation; 9 cases of primary central nervous system, 11 cases of primary testicular and 11 cases of other primary extranodal diffuse large B-cell lymphomas. All cases were analyzed with qRT-PCR. In situ hybridization for the most differentially expressed miRNAs was performed to show miRNA expression in tumor cells, but not in background cells. MiR-21 and miR-19b showed the highest expression levels. No significant differences were seen between germinal center and non-germinal center diffuse large B-cell lymphomas in either the total or the nodal group for any of the 15 miRNAs. Two miRNAs showed significant differences in expression levels for diffuse large B-cell lymphoma subgroups according to the site of presentation. MiR-17-5p showed a significant higher expression level in the central nervous system compared with testicular and nodal diffuse large B-cell lymphomas (P<0.05). MiR-127 levels were significantly higher in testicular than in central nervous system and in nodal diffuse large B-cell lymphomas (P<0.05). We conclude that the location of diffuse large B-cell lymphoma is an important factor in determining the differential expression of miRNAs.

JNK is constitutively active in mantle cell lymphoma: cell cycle deregulation and polyploidy by JNK inhibitor SP600125.

Mantle cell lymphoma (MCL) is characterized by genetic instability and a poor prognosis. Many blastoid variants are (hypo)tetraploid and have an even worse prognosis. We investigated the role of signalling by mitogen-activated protein kinases (MAPKs) in MCL. As compared to normal tonsil B cells, MCL cells showed higher activation of the JNK MAPK in both an MAPK array and a sandwich ELISA assay. Immunohistochemistry showed overexpression of phospho (p)-JNK (Thr183/Tyr185) in 30 of 37 MCL cases. Inhibition of p-JNK with SP600125 resulted in growth arrest in all four MCL cell lines (Jeko-1, HBL-2, UPN-1, Granta-519), which could be partly reversed by the addition of CD40L and IL-4. Furthermore, SP600125 led to G2/M phase arrest on day 1 and a striking increase in endoreduplication on day 2 and day 3, which was confirmed by karyotype analysis. G2/M arrest was associated with down-regulation of EGR1 and p21 protein expression. SP600125-induced polyploidy could be blocked by the BCL-2 inhibitor YC137. These data suggest that constitutive JNK activity is necessary to promote proliferation and maintain diploidy in MCL. JNK inhibition leads to cell cycle deregulation and endoreduplication, mimicking the tetraploid state seen in a subset of MCL cases. Thus, our data also provide an experimental model to study polyploid MCL cells.