Ruxolitinib shows activity against Hodgkin lymphoma but not primary mediastinal large B-cell lymphoma.

BACKGROUND: The upregulated expression of the JAK/STAT pathway promotes tumor growth in Hodgkin lymphoma (HL) and primary mediastinal large B-cell lymphoma (PMBCL). Based on the hypothesis that JAK2 is a therapeutic target, we performed a prospective pilot study using ruxolitinib. METHODS: Relapsed or refractory patients with HL or PMBCL were eligible for this study, and JAK2 amplification was assessed by fluorescence in situ hybridization. Ruxolitinib was administered orally at a dose of 20 mg twice daily for a 28-day cycle. Treatment was continued for up to 16 cycles or until progressive disease or intolerability. The primary objective was to assess the overall disease control rate comprising complete response (CR), partial response (PR), or stable disease (SD). RESULTS: We analyzed 13 HL patients and six PMBCL patients. All responders (one CR, five PR, and one SD) had HL whereas all cases of PMBCL progressed after first or second cycle. The disease control rate for HL was 54% (7/13) with median response duration of 5.6 months. JAK2 amplification was present in six of nine patients tested (four HL, two PMBCL), and three of these HL patients showed PR (n = 2) or SD (n = 1). None of the three HL patients shown to not have JAK2 amplification responded to ruxolitinib. Most treatment-related adverse events were grade 1 or 2 and manageable. CONCLUSIONS: Ruxolitinib has single-agent activity against HL but does not act against PMBCL with or without JAK2 amplification. TRIAL REGISTRATION: The study population was patients who had relapsed or refractory HL or PMBCL, and patients were registered for our pilot study after providing written informed consent between November 2013 and November 2015 (CilinicalTrials.gov: NCT01965119).

TdT expression in germ cell tumours: a possible immunohistochemical cross-reaction and diagnostic pitfall.

AIMS: Very recent papers proposed a possible role for the expression of terminal deoxynucleotidyl transferase (TdT) in the tumourigenesis of gonadal and extragonadal germ cell-derived tumours (GCTs). Our multicentric study evaluated the magnitude of the immunoreactivity for TdT in GCTs, encompassing seminoma, dysgerminoma, mature teratoma and mixed GCTs. METHODS AND RESULTS: The histological series was stained with both monoclonal and polyclonal antibodies, yielding a positivity of 80% of cases with well-defined nuclear reactivity. A significant difference in staining intensity between monoclonal and polyclonal antibodies was observed (p=0.005). However, exploiting western blot and more innovative proteomic approaches, no clear-cut evidence of the TdT protein was observed in the neoplastic tissues of the series. CONCLUSIONS: Alternatively to the pathogenetic link between TdT expression and GCTs tumourigenesis, we hypothesised the occurrence of a spurious immunohistochemical nuclear cross-reaction, a well-known phenomenon with important implications and a possible source of diagnostic pitfalls in routine practice for pathologists.

Can pancreatic tissue cause haemoptysis?

A mature teratoma is a tumour of primary germ cells. It is often found in the mediastinum. The authors describe a case of a young man who demonstrated haemoptysis as the only symptom of a mediastinal tumour. The tumour was removed operatively, sent for histopathological examination and immunohistochemistry. The removed tumour was a mature teratoma including elements of the pancreas. The authors revealed the presence of trypsin in the pancreatic acinar cells. The proteolytic activity of the tumour was taken as the cause of haemoptysis because of enzymatic erosion of lung tissue intimately attached to the tumour. In such cases surgical removal saves life of patients.

Enlarging cystic lymphangioma of the mediastinum in an adult: is this a neoplastic lesion related to the recently discovered PIK3CA mutation?

Cystic lymphangioma, a lymphatic system malformation, is usually observed in infants and children and is rarely found in adults. It most commonly occurs in the cervicofacial region, followed by the axilla. Mediastinal cystic lymphangioma is rare, accounting for 1.8% of all mediastinal cysts. Herein, we present an exceedingly rare adult case of mediastinal cystic lymphangioma that had increased in size over a 5-year period. Although fluid collection might be an alternative explanation for this increase in size, this lymphangioma might harbor a neoplastic nature related to the recently discovered PIK3CA mutation.

DNMT3B7, a truncated DNMT3B isoform expressed in human tumors, disrupts embryonic development and accelerates lymphomagenesis.

Epigenetic changes are among the most common alterations observed in cancer cells, yet the mechanism by which cancer cells acquire and maintain abnormal DNA methylation patterns is not understood. Cancer cells have an altered distribution of DNA methylation and express aberrant DNA methyltransferase 3B transcripts, which encode truncated proteins, some of which lack the COOH-terminal catalytic domain. To test if a truncated DNMT3B isoform disrupts DNA methylation in vivo, we constructed two lines of transgenic mice expressing DNMT3B7, a truncated DNMT3B isoform commonly found in cancer cells. DNMT3B7 transgenic mice exhibit altered embryonic development, including lymphopenia, craniofacial abnormalities, and cardiac defects, similar to Dnmt3b-deficient animals, but rarely develop cancer. However, when DNMT3B7 transgenic mice are bred with Emicro-Myc transgenic mice, which model aggressive B-cell lymphoma, DNMT3B7 expression increases the frequency of mediastinal lymphomas in Emicro-Myc animals. Emicro-Myc/DNMT3B7 mediastinal lymphomas have more chromosomal rearrangements, increased global DNA methylation levels, and more locus-specific perturbations in DNA methylation patterns compared with Emicro-Myc lymphomas. These data represent the first in vivo modeling of cancer-associated DNA methylation changes and suggest that truncated DNMT3B isoforms contribute to the redistribution of DNA methylation characterizing virtually every human tumor.

Expression and clinical significance of heparanase in neuroblastoma.

BACKGROUND: Previous studies indicate that heparanase (HPA), an endoglycosidase involved in tumor angiogenesis and metastasis, is up-regulated in a variety of malignancies. However, the expression of HPA in neuroblastoma (NB), one of the most common extra cranial solid tumors in children, remains unknown. This study was undertaken to explore the expression and clinical significance of HPA in NB. METHODS: Immunohistochemical staining was applied to detect the expression of HPA in 42 cases of NB. The relationships among HPA expression, international neuroblastoma staging system (INSS) stages, histopathological classification, and postoperative survival of the NB patients were analyzed. RESULTS: The expression rate of HPA in NB was 61.9% (26/42), mainly in the cytoplasm of neuroblastoma cells. The expression rates of stage 1-2, stage 3-4 and stage 4S were 35.7%, 80.0% and 62.5%, respectively. The differences between stage 1-2 and stage 3-4 were significant (P<0.01). The expression of HPA was significantly higher in the NB cases that had one of the histopathological factors: age more than 1 year (P<0.01), poorer differentiation (P<0.01), and higher mitosis karyorrhexis index (P<0.01). The survival time of HPA-negative patients was significantly longer than that of HPA-positive patients (P<0.05). CONCLUSION: Although these results indicate that heparanase might be correlated with development and progression of NB, a larger series of patients with a longer follow-up are probably needed to strengthen its role in assessment of NB prognosis.

Exhaled nitric oxide and nitric oxide synthase expression in Hodgkin's disease.

Hodgkin's disease (HD) is a malignant lymphoma with frequent mediastinal involvement, characterized by a significant inflammatory infiltration. Exhaled nitric oxide (FENO), is present in healthy humans, and has been proven to be increased in eosinophilic diseases such as allergic asthma. We investigated whether FENO is increased in mediastinal HD and whether NO is produced by lymphoma tissue. To this aim FENO was measured in 56 HD patients, 17 with and 39 without bulky mediastinal involvement, in the period from January 2007 to December 2008. Thirty-seven patients were reassessed after remission. Lymph node biopsies of 10 patients were evaluated for inducible (iNOS) and constitutive (eNOS) nitric oxide synthase expression by immunohistochemistry. FENO resulted significantly related to the mediastinal mass maximum diameter (p=0.009) and was significantly higher in patients with as compared to those without bulky mediastinal disease (38.7 ppb, CI 95% 19.3-58.0, versus 20.7 ppb, CI 95% 16.6-24.7; p=0.009). iNOS and eNOS immunoreactivity was observed in tumour and inflammatory cells (eosinophils and histiocytes). Only in patients with bulky mediastinal HD there was a significant decrease in FENO (from 50.4 ppb CI 95% 18.0-82.8 to 11.1 ppb CI 95% 4.4-17.8, p=0.011). In conclusion, high FENO and NOS expression in lymph-nodes indicate that NO is a component of the inflammatory network of HD. FENO may be proposed for the assessment and follow up of bulky mediastinal HD patients.

Aberrant somatic hypermutation and expression of activation-induced cytidine deaminase mRNA in mediastinal large B-cell lymphoma.

To determine the possible role of aberrant somatic hypermutation (ASHM) and activation-induced cytidine deaminase (AID) expression in the pathogenesis of mediastinal large B-cell lymphoma (MBL), the mutational status of genes affected by ASHM, including c-MYC, PAX-5 and RhoH, was analysed, and the expression level of AID mRNA in tumour specimens from six patients with MBL was determined. Mutations in one or more genes and high expression of AID mRNA were detected in all the six cases of MBL. These results suggest that ASHM and AID expression may have a role in the pathogenesis of MBL.

Inflammatory myofibroblastic tumor of the posterior mediastinum: an older adult case with anaplastic lymphoma kinase abnormalities determined using immunohistochemistry and fluorescence in situ hybridization.

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm that usually occurs in children and young adults. Anaplastic lymphoma kinase (ALK) abnormalities in IMT, determined using immunohistochemistry and/or molecular genetic studies, including fluorescence in situ hybridization (FISH), have almost been limited to children and young adults. In elderly cases of IMT, these ALK abnormalities are very rare. We report on a case of IMT arising in the posterior mediastinum of a 59-year-old Japanese man that showed ALK abnormalities determined using immunohistochemistry and FISH, suggesting the neoplastic nature of a subset of IMTs in older patients similar to those in younger ones and the presence of an additional mechanism(s) that allows them to start to grow late.

A novel syngeneic murine model for thoracic neuroblastoma obtained by intramediastinal injection of tumor cells.

In this study, a new syngeneic murine neuroblastoma (NB) model resembling stage 3 NB with thoracic localization has been set up by intramediastinal injection of tumor cells. Two NB cell lines, the murine Neuro2a, and the hybrid NXS2, have been injected in A/J mice. In vivo tumor growth and dissemination have been assessed by macroscopic and microscopic histological analysis performed at different times post injection. Tumor cell localization and growth patterns were compared to those obtained by i.v. and r.p. injections. The results indicated that in the thoracic model both tumor cell lines grow rapidly as huge tumor masses but do not metastatize to distant organs. This new model may be relevant for testing the efficacy of novel immunotherapeutic strategies for poor prognosis NB patients with localized disease.

Blastic natural killer cell lymphoma arising from the mediastinum with terminal deoxynucleotidyl transferase expression.

Blastic natural killer (NK) cell lymphoma/leukemia is a relatively rare NK cell malignancy. We report the second case of blastic NK cell lymphoma arising from the mediastinum with an aggressive clinical course. The patient was a 63-year-old Japanese man with an anterior mediastinum tumor. The biopsy specimen showed diffuse proliferation of tumor cells with frequent mitotic figures and apoptotic bodies. Both angiocentric features and small foci of coagulative necrosis were found in this section. The tumor cells had medium to large nuclei with a fine chromatin pattern, inconspicuous nucleoli and scanty cytoplasm. The nuclear contour was oval to moderately irregular, showing slight pleomorphism as compared with typical lymphoblastic lymphoma. The tumor cells were positive for CD2, CD56 and terminal deoxynucleotidyl transferase, but negative for other T-cell antigens, B-cell antigens and myeloid markers. In situ hybridization for Epstein-Barr virus encoded small ribonucleic acid 1 was negative.

Do neuron-specific enolase levels discriminate between small-cell lung cancer and mediastinal tumors?

The capacity of pretherapeutically assessed neuron-specific enolase (NSE) to differentiate between small cell lung cancer (SCLC) and mediastinal tumors was investigated retrospectively in a series of 320 patients. NSE was found to be increased in 95/130 (73.1%) patients with SCLC, in 4/62 (6.5%) patients with Hodgkin's disease, in 10/58 (17.2%) patients with non-Hodgkin's lymphoma, in 5/16 (31.3%) patients with teratoma, and in 6/54 (11.1%) patients with thymoma. The cut-off value, defined as the 95% percentile of a reference population suffering from benign pulmonary disorders (n = 192), was set at 13.8 ng/ml. When this discrimination level was increased to 26.4 ng/ml, which corresponds to a 95% specificity versus the total group with mediastinal tumors, SCLC was recognized with a detection rate of only 49.2%. In conclusion, increased NSE concentrations in a patient with a hilar mass and/or mediastinal widening on X-ray are not always diagnostic of SCLC due to the high rate of elevated NSE values associated with mediastinal tumors. However, in a patient who presents with a hilar mass and a high NSE level, bronchoscopy is always indicated to obtain adequate specimens for histology in order to plan an appropriate therapeutic regimen.

Exocrine pancreatic function in mediastinal teratomata: an aid to preoperative diagnosis?

The diagnosis of teratoma may be made by demonstration of high amylase content in fluid aspirated from anterior mediastinal lesions. In 2 cases of mediastinal teratoma proteolytic enzyme activity was evident at the time of operation. A diagnosis of mediastinal teratoma was aided in 2 subsequent cases by demonstration of elevated amylase activity in the aspirated fluid before definitive operation.

Neuron-specific enolase and thymidine kinase as an aid to the diagnosis and treatment monitoring of small cell lung cancer.

The serum levels of neuron specific enolase (s-NSE) and thymidine kinase (s-TK) were studied in detail in patients with small cell lung cancer (SCLC) to evaluate as to whether their combined use may aid to diagnosis and follow-up of this particular tumor. Only s-NSE could differentiate between SCLC and non-small cell lung cancer (NSCLC) or benign pulmonary diseases (BPD) to some extent, pathologic serum concentrations occurring in 81%, 17%, and 0%, respectively. The comparable figures for s-TK were 62%, 24%, and 28%, respectively. Serum NSE decreased and increased paralleling tumor regression and progression, respectively, except when brain metastases were present. Alterations of s-TK, in contrast, did not usually mirror the course of disease. During initial chemotherapy (CT) a transitory increase of serum levels was observed for both NSE and TK. Monitoring, based on daily blood samples, showed comparable peaks only for s-TK during the following CT cycles, whereas s-NSE was within the normal range even when tumor mass was still present. Those subsequent s-TK peaks under CT may be due to tumor cell lysis as a result of CT indicating the efficacy of treatment by this way. Rapidly proliferating tissues such as bone marrow or bowel mucosa, however, have also to be considered as possible sources of s-TK.

Secretion of creatine kinase MB isoenzyme by an immature teratoma with predominant rhabdomyosarcomatous elements.

A 37-year-old man with metastatic immature (malignant) teratoma with prominent rhabdomyosarcomatous elements had markedly increased activity of creatine kinase (EC 2.7.3.2) MB in serum. There was no electrocardiographic evidence of infarction or ischemia, and autopsy revealed no myocardial infarction, significant coronary atherosclerosis, myocarditis, or invasion of the heart by tumor. A high proportion of the creatine kinase activity in a homogenate of the tumor was attributable to the MB isoenzyme. Persistent increases of creatine kinase-MB and an unusually high MB isoenzyme activity, out of proportion to total creatine kinase activity, may indicate a nonmyocardial origin of this isoenzyme.

Lactate dehydrogenase isoenzyme-1 in the mediastinal yolk sac tumor.

LDH isozymes in both the serum and tumor tissues of 4 patients with mediastinal yolk sac tumors, and in the cystic content of tumors transplanted into nude mice was examined. Our findings suggested that LDH-1, along with AFP, is an important marker of this tumor, and that LDH isozyme study is necessary for its diagnosis.

Isoenzymes of alkaline phosphatase in germinoma cells.

Utilizing 18 germinomas, the characteristics of isoenzymes of alkaline phosphatase (ALP) in germinoma cells were examined by light and electron microscopic enzymohistochemical and immunohistochemical techniques and biochemical methods including inhibition tests, electrophoresis and electrosyneresis. ALP in germinoma cells was generally located on the cell surface. In a few germinoma cells, however, ALP was seen not only on the cell membrane but also in the endoplasmic reticulum. Enzymohistochemically as well as biochemically, ALP in germinoma cells was little sensitive to L-phenylalanine, moderately sensitive to L-homoarginine and somewhat resistant to heat in its inhibition tests. Immunohistochemical examinations and electrosyneresis showed the presence of the placental type of ALP in germinoma cells and biochemical analyses revealed that the heat-stable component of ALP in germinoma cells was consistent with the D-variant of the placental type of ALP. Therefore, germinoma cells possessed mixed isoenzymes of ALP, consisting mainly of the liver/bone type and a small amount of D-variant of the placental type on the cell surface. The prominent expression of ALP in germinoma cells may be due to the enhanced expression of gonadal genes active in the germinoma genome.