Molecular and immunophenotypic characterization of SMARCB1 (INI1) - deficient intrathoracic Neoplasms.

The switch/sucrose-non-fermenting (SWI/SNF) complex is an ATP-dependent chromatin remodeling complex that plays important roles in DNA repair, transcription and cell differentiation. This complex consists of multiple subunits and is of particular interest in thoracic malignancies due to frequent subunit alteration of SMARCA4 (BRG1). Much less is known about SMARCB1 (INI1) deficient intrathoracic neoplasms, which are rare, often misclassified and understudied. In a retrospective analysis of 1479 intrathoracic malignant neoplasms using immunohistochemistry for INI1 (SMARCB1) on tissue micro arrays (TMA) and a search through our hospital sarcoma database, we identified in total nine intrathoracic, INI1 deficient cases (n = 9). We characterized these cases further by additional immunohistochemistry, broad targeted genomic analysis, methylation profiling and correlated them with clinical and radiological data. This showed that genomic SMARCB1 together with tumor suppressor alterations drive tumorigenesis in some of these cases, rather than epigenetic changes such as DNA methylation. A proper diagnostic classification, however, remains challenging. Intrathoracic tumors with loss or alteration of SMARCB1 (INI1) are highly aggressive and remain often underdiagnosed due to their rarity, which leads to false diagnostic interpretations. A better understanding of these tumors and proper diagnosis is important for better patient care as clinical trials and more targeted therapeutic options are emerging.

Fingolimod and tumor-infiltrating lymphocytes in checkpoint-inhibitor treated cancer patients.

Immune checkpoint inhibitors (ICIs) are emerging as the new standard of care for treating various metastatic cancers. It is known that effective anti-tumor immune responses are associated with a stronger presence of tumor-infiltrating lymphocytes (TILs) in solid tumor tissue. Cancer patients with relapsing-remitting multiple sclerosis (RRMS) are often under continuous treatment with fingolimod, an immune-modulating drug that inhibits lymphocyte egress from secondary lymphatic organs. Little is known about the effect of fingolimod on ICI cancer therapy, as fingolimod may limit the number of TILs. Here we present three patients with RRMS, who developed various cancers during fingolimod treatment. Histology of all tumors consistently showed low numbers of TILs. A second biopsy taken from one of the tumors, a melanoma, revealed a significant increase of TILs after stopping fingolimod and starting pembrolizumab, indicating a surge in the number and re-invigoration of T cells. Our study suggests that fingolimod limits the number of TILs in solid tumors and may, thus, inhibit anti-cancer immune responses.

Spindle cell/pleomorphic lipoma of the seminal vesicle: First description of a rare benign mesenchymal tumor.

We describe the first case of a spindle cell/pleomorphic lipoma of the seminal vesicle. A 6.2cm large mass originating from the left seminal vesicle was incidentally detected on imaging for peripheral arterial disease. A transrectal ultrasound-guided biopsy was negative for malignancy. We proceeded with a robotic tumor resection due to the size of the mass and sarcomatoid features present on MR imaging. The final pathological work-up revealed a spindle cell/pleomorphic lipoma, immunohistochemical staining was performed with no malignant features detected, in particular no signs of an atypical lipomatous tumor. Ejaculatory function was preserved with reduced volume at 6-weeks follow-up.

Evolution of PTLD following renal transplantation in a child.

We report the case of an eight-yr-old child with early onset PTLD half a year after renal transplantation. The patient developed gastrointestinal pain and bowel biopsies revealed imposing lymphoid infiltrates with small spots of lymphoid blasts in the colonic mucosa. These findings were interpreted as transplantation associated B-cell stimulation. However, the persistent severe abdominal pain led to the resection of a jejunal segment. Here, gut wall perforation caused by a tumor mass was seen. Histologically, a blastic lymphoid cell proliferation of B-cell origin with high proliferation rate and EBV association could be demonstrated. IgH rearrangement analysis and in situ hybridization revealed an oligoclonal B-cell pattern. Reduction of immunosuppression and treatment with rituximab led to lymphoma remission and conversion of EBV serology four wk later. The report presented herein demonstrates the evolution of an oligoclonal lymphoproliferation with direct disease progression towards EBV associated PTLD by analyzing different stages of the disease.

FOS Expression in Osteoid Osteoma and Osteoblastoma: A Valuable Ancillary Diagnostic Tool.

Osteoblastoma and osteoid osteoma together are the most frequent benign bone-forming tumor, arbitrarily separated by size. In some instances, it can be difficult to differentiate osteoblastoma from osteosarcoma. Following our recent description of FOS gene rearrangement in these tumors, the aim of this study is to evaluate the value of immunohistochemistry in osteoid osteoma, osteoblastoma, and osteosarcoma for diagnostic purposes. A total of 337 cases were tested with antibodies against c-FOS: 84 osteoblastomas, 33 osteoid osteomas, 215 osteosarcomas, and 5 samples of reactive new bone formation. In all, 83% of osteoblastomas and 73% of osteoid osteoma showed significant expression of c-FOS in the osteoblastic tumor cell component. Of the osteosarcomas, 14% showed c-FOS expression, usually focal, and in areas with severe morphologic atypia which were unequivocally malignant: 4% showed more conspicuous expression, but these were negative for FOS gene rearrangement. We conclude that c-FOS immunoreactivity is present in the vast majority of osteoblastoma/osteoid osteoma, whereas its expression is usually focal or patchy, in no more than 14% of osteosarcoma biopsies. Therefore, any bone-forming tumor cases with worrying histologic features would benefit from fluorescence in situ hybridization analysis for FOS gene rearrangement. Our findings highlight the importance of undertaking a thorough assessment of expression patterns of antibodies in the light of morphologic, clinical, and radiologic features.

Lung osteoma--a new benign lung lesion.

Extraskeletal osteomas have not been described in the lung. Tumors with osseous elements can be found, such as hamartoma and amyloid tumor, and reactive lesions such as osseous metaplasia. A 39-year-old male patient was treated for multiple myeloma and got a bone marrow transplantation 2 years and a few months before he presented with a solitary well-circumscribed tumor in the right middle lobe. The patient underwent surgical resection. The tumor presented with a fibrous capsule and consisted of mature bone trabecules. Within the tumor, fatty tissue was seen. There were small bone spicules interpreted as areas of new bone formation and appositional growth. No amyloid deposition, no immature epithelial tubules as in hamartomas, and no normal lung structure as in osseous metaplasia were seen. Within the osseous elements, a positive reaction was seen with antibodies for osteonectin, whereas the reaction for calcitonin was negative. To the best of our knowledge, this is the first case of an osteoma being reported in the lung looking like any other extraskeletal osteoma. This tumor might have been induced by circulating stem cells; however, due to autologous bona marrow transplantation, this cannot be proven.

Enhanced proliferation and decreased apoptosis in lung lavage cells of sarcoidosis patients.

BACKGROUND: Sarcoidosis is a systemic autoimmune disease where an inflammatory reaction involving alveolar macrophages, T-helper lymphocytes, and epitheloid cells is mounted against unknown antigens. A genetic predisposition for sarcoidosis is supposed by studies in twins, by geographical and racial distribution. In the current investigation we compared the expression patterns between slow onset and acute sarcodosis using a whole-genome cDNA array. METHODS: Bronchoalveolar lavage was performed in six patients with slow onset sarcoidosis and four patients with acute sarcoidosis (Löfgren's disease) and obtained cells were used for gene expression profiling. The results were confirmed by RT- and Taqman-PCR. In addition, protein expression was examined on paraffin sections of sarcoid granulomas by immunohistochemistry. RESULTS: In T-helper lymphocytes and alveolar macrophages we found an upregulation of genes belonging to the phosphoinositol-3-kinase/v-akt murine thymoma viral oncogene homolog/signal transducer and activator of transcription 3 pathway, as well as a downregulation of genes of the extrinsic and intrinsic apoptotic signaling cascades. In addition an upregulation of the genes encoding fatty acid binding protein 4 and 5, as well as peroxisome proliferative activated receptor delta in Löfgren's disease was detected. Differences in gene expression between slow onset sarcoidosis and Löfgren's syndrome were found mainly within genes of the major histocompatibility complex. CONCLUSIONS: In sarcoidosis enhanced cell proliferation and decreased apoptosis result in accumulation and prolonged survival of antigen-primed T-helper lymphocytes and activated macrophages. This is enhanced in Löfgren's disease, probably by hyper-stimulation via the peroxisome proliferation signaling, providing a larger pool of antigen-primed immune cells.

Characterization of nivolumab-associated skin reactions in patients with metastatic non-small cell lung cancer.

Immune checkpoint inhibitors have led to considerable therapy improvement in cancer patients. Autoimmune side effects including skin reactions are frequently observed. In melanoma, those include rash and vitiligo and were shown to be associated with a prolonged overall survival. Little is known about skin reactions in non-small cell lung cancer (NSCLC) patients during immunotherapy. Here, we retrospectively investigated immune-related adverse skin reactions (irAEs) in 40 patients with metastatic NSCLC treated with the anti-PD-1 antibody nivolumab. 7 out of 40 patients (17%) developed an irAEs. Skin irAEs correlated with tumor responses in 5 of 12 responders (42%) as compared to 2 of 27 non-responders (7%). Histologically, scaly plaques showed dermatitis consisting mainly of lymphocytes. We observed a positive correlation between skin irAEs and tumor responses in patients with NSCLC treated with nivolumab. Patterns of lymphocytic skin infiltration differed depending on the histological tumor subtype (adenocarcinoma versus squamous cell carcinoma NSCLC).

Improving the efficacy of targeted trials by multiple-marker analysis in castration-resistant prostate cancer.

OBJECTIVES: In order to improve the efficacy of targeted therapy trials, the expression profiles of several molecular markers that are potential candidates for targeted therapy were analyzed in patients with progressive castration-resistant prostate cancer. METHODS AND MATERIALS: Paraffin-embedded samples of tumor tissue from 51 patients obtained from biopsies of metastases or remaining prostates were analyzed immunohistochemically for the expression of EGFR, PDGFRß, Her-2/neu, c-Kit, and VEGF. Staining was analyzed according to the percentage of positively stained tumor cells and the intensity of staining. RESULTS: According to the different cut-off values of 10%, 30%, 50%, or 70% for the percentage of positively stained cells, different rates of expression were found. Expression rates ranged from 30.6% to 61.2% for EGFR, from 34.7% to 57.1% for PDGFRß, from 9.6% to 28.8% for Her-2/neu, from 12.5% to 22.4% for c-Kit, and from 51.1% to 74.5% for VEGF. Defining positive expression as ≥ 30% positively stained tumor cells, with an intensity of staining of ≥ 2+, resulted in positive expression of EGFR in 38.8%, PDGFRß in 24.5%, Her-2/neu in 13.5%, c-Kit in 6.4%, and VEGF in 44.7% of the patients. CONCLUSIONS: Our results demonstrate simultaneous expression of several markers in castration-resistant prostate cancer tissue. Translation of the results into modern, multi-arm clinical trial designs will improve the efficacy of recruiting and obtaining results, compared with multiple double-arm trials.

Benchmarking of mutation diagnostics in clinical lung cancer specimens.

Treatment of EGFR-mutant non-small cell lung cancer patients with the tyrosine kinase inhibitors erlotinib or gefitinib results in high response rates and prolonged progression-free survival. Despite the development of sensitive mutation detection approaches, a thorough validation of these in a clinical setting has so far been lacking. We performed, in a clinical setting, a systematic validation of dideoxy 'Sanger' sequencing and pyrosequencing against massively parallel sequencing as one of the most sensitive mutation detection technologies available. Mutational annotation of clinical lung tumor samples revealed that of all patients with a confirmed response to EGFR inhibition, only massively parallel sequencing detected all relevant mutations. By contrast, dideoxy sequencing missed four responders and pyrosequencing missed two responders, indicating a dramatic lack of sensitivity of dideoxy sequencing, which is widely applied for this purpose. Furthermore, precise quantification of mutant alleles revealed a low correlation (r(2) = 0.27) of histopathological estimates of tumor content and frequency of mutant alleles, thereby questioning the use of histopathology for stratification of specimens for individual analytical procedures. Our results suggest that enhanced analytical sensitivity is critically required to correctly identify patients responding to EGFR inhibition. More broadly, our results emphasize the need for thorough evaluation of all mutation detection approaches against massively parallel sequencing as a prerequisite for any clinical implementation.

High diagnostic value of morphologic examination and molecular analysis of bone marrow biopsies in a case of BCR-ABL+ CML with clusters of blasts.

We report a clinical case of chronic myelogenous leukaemia (CML) with regional B-lymphoblastic transformation. Peripheral leukocytosis of 160 x 10(9)/L, splenomegaly and fatigue suggested CML. In peripheral blood and bone marrow smears, white blood cells in all maturation stages and only few blasts were seen and therefore the diagnosis of chronic phase CML was proposed. Cytogenetics performed on peripheral blood cells revealed the characteristic t(9;22)(q34;q11) translocation as solitary abnormality. Analyzing the bone marrow biopsy a focal nodular B-lymphoid blast component was additionally seen. BCR-ABL FISH analysis demonstrated 31% atypical split signals in the B-lymphoid blasts and in the maturing myeloid cells, furthermore, BCR-ABL fusion transcripts were seen in the RT-PCR assay. Imatinib-based therapy led to temporary regression of peripheral leukocytosis. Bone marrow examination 3 weeks after therapy induction demonstrated considerably reduced cellularity and the proportion of B-lymphoid blasts had decreased to 20% of the nuclear cells. BCR-ABL FISH analysis still presented 21% atypical split signals but levels of BCR-ABL transcripts had significantly fallen indicating a rather favourable prognosis. However, 3 months after diagnosis the patient relapsed and developed an immunodeficiency with soor esophagitis and aspergillus pneumonia. A therapy with dasatinib was not successful and the patient died in consequence of immunodeficiency. This report demonstrates the high diagnostic value of bone marrow biopsy in the evaluation of CML. Besides morphology investigation of diverse methods including RT-PCR and FISH performed on diagnostic bone marrow biopsies are obligatory for ideal monitoring of drug response.