Superficial GLI1-amplified mesenchymal neoplasms: Expanding the spectrum of an emerging entity which reaches the realm of dermatopathology.

Mesenchymal neoplasms with GLI1 alterations (rearrangements and/or amplification) have been reported recently in several anatomic locations, which include head and neck, soft tissue, and gastrointestinal tract. Herein, to the best of our knowledge, we describe the first three cases of superficial/subcutaneous mesenchymal neoplasm with GLI1 amplification. The neoplasms exhibited low-grade cytologic features with predominant round cell morphology, glomangioma-like areas and a rich background capillary network. There were two to three mitotic figures per 10 HPF and focal necrosis in one case. The tumors exhibited variable expression of CDK4, MDM2, STAT6, D2-40, CD56 and cyclin D1. p16 had strong and diffuse nuclear and cytoplasmic expression in two cases. Numerous other stains were negative. Fluorescence in situ hybridization detected GLI1, DDIT3, and CDK4 coamplification in all cases, while next generation sequencing did not detect a GLI1 gene fusion. The overall features were compatible with a GLI1-amplified mesenchymal neoplasm. In Case 1 a new distant skin lesion appeared 1 month after the surgery exhibiting similar morphology albeit with a higher mitotic index. In Cases 2 and 3, there is no evidence of local recurrence or systemic disease after 8 years and 1 month of follow-up, respectively. These new cases of superficial GLI1-amplified neoplasm expand its clinical spectrum and enter the realm of dermatopathology. The combination of CDK4, cyclin D1, D2-40, and p16 expression with variable MDM2, STAT6, CD56, and S100 immunoreactivity in a low-grade neoplasm with round/ovoid cytomorphology resembling a vascular or adnexal neoplasm may suggest the possibility of GLI1-amplified neoplasm.

Atypical Histiocytic Lesion Preceding a Peripheral T-Cell Lymphoma Involving the Skin Exhibiting the Same Molecular Alterations.

Peripheral T-cell lymphoma (PTCL), not otherwise specified (NOS) is a diagnosis of exclusion, showing extreme cytological and phenotypic heterogeneity. Skin involvement of PTCL may be primary or secondary. Diagnosis of histiocytosis may be difficult, requiring clinical-pathological correlation. We describe a laryngeal atypical histiocytic lesion (AHL) and a nasal PTCL, NOS with cutaneous involvement in the same patient presenting with peculiar histopathologic and immunophenotypic features. The laryngeal neoplasm showed morphological and immunophenotypic evidence of histiocytic differentiation and does not fit any other category of the WHO classification nor the revised classification of histiocytosis. The nasal and cutaneous lesions presented features close to natural killer/T-cell lymphoma and gamma-delta T-cell lymphoma but did not meet accurately the WHO criteria. A somatic activating Q61K mutation was found on exon 3 of the NRAS gene in both AHL and PTCL, NOS. The mutation on NRAS gene in both AHL and PTCL, NOS may suggest a common origin from a precursor cell.

Apoptosis for prediction of radiotherapy late toxicity: lymphocyte subset sensitivity and potential effect of TP53 Arg72Pro polymorphism.

We tested apoptosis levels in in vitro irradiated T-lymphocytes from breast cancer (BC) patients with radiotherapy-induced late effects. Previous results reported in the literature were revised. We also examined the effect of TP53 Arg72Pro polymorphism on irradiation-induced apoptosis (IA). Twenty BC patients, ten with fibrosis and/or telangiectasias and ten matched controls with no late reactions, were selected from those receiving radiotherapy between 1993 and 2007. All patients were followed-up at least 6 years after radiotherapy. Using the combination of both CD3 and CD8 antibodies the in vitro IA was measured in CD3, CD8 and CD4 T-lymphocytes, and CD8 natural killer lymphocytes (CD8 NK) by flow cytometry. The TP53 Arg72Pro genotype was determined by sequencing. Patients with late radiotherapy toxicity showed less IA for all T-lymphocytes except for the CD8 NK. CD8 NK showed the highest spontaneous apoptosis and the lowest IA. IA in patients with toxicity appears to be lower than the control patients only in TP53 Arg/Arg patients (P = 0.077). This difference was not present in patients carrying at least one Pro allele (P = 0.8266). Our data indicate that late side effects induced by radiotherapy of BC are associated to low levels of IA. CD8 NK cells have a different response to in vitro irradiation compared to CD8 T-lymphocytes. It would be advisable to distinguish the CD8 NK lymphocytes from the pool of CD8+ lymphocytes in IA assays using CD8+ cells. Our data suggest that the 72Pro TP53 allele may influence the IA of patients with radiotherapy toxicity.

Pyrosequencing-Based Assays for Rapid Detection of HER2 and HER3 Mutations in Clinical Samples Uncover an E332E Mutation Affecting HER3 in Retroperitoneal Leiomyosarcoma.

Mutations in Human Epidermal Growth Factor Receptors (HER) are associated with poor prognosis of several types of solid tumors. Although HER-mutation detection methods are currently available, such as Next-Generation Sequencing (NGS), alternative pyrosequencing allow the rapid characterization of specific mutations. We developed specific PCR-based pyrosequencing assays for identification of most prevalent HER2 and HER3 mutations, including S310F/Y, R678Q, L755M/P/S/W, V777A/L/M, 774-776 insertion, and V842I mutations in HER2, as well as M91I, V104M/L, D297N/V/Y, and E332E/K mutations in HER3. We tested 85 Formalin Fixed and Paraffin Embbeded (FFPE) samples and we detected three HER2-V842I mutations in colorectal carcinoma (CRC), ovarian carcinoma, and pancreatic carcinoma patients, respectively, and a HER2-L755M mutation in a CRC specimen. We also determined the presence of a HER3-E332K mutation in an urothelial carcinoma sample, and two HER3-D297Y mutations, in both gastric adenocarcinoma and CRC specimens. The D297Y mutation was previously detected in breast and gastric tumors, but not in CRC. Moreover, we found a not-previously-described HER3-E332E synonymous mutation in a retroperitoneal leiomyosarcoma patient. The pyrosequencing assays presented here allow the detection and characterization of specific HER2 and HER3 mutations. These pyrosequencing assays might be implemented in routine diagnosis for molecular characterization of HER2/HER3 receptors as an alternative to complex NGS approaches.

Actionable mutational profiling in solid tumors using hybrid-capture-based next-generation sequencing in a real-world setting in Spain.

OBJECTIVE: This study aimed to describe the performance of a next-generation sequencing (NGS) panel for the detection of precise genomic alterations in cancer in Spanish clinical practice. The impact of tumor characteristics was evaluated on informative NGS and actionable mutation rates. MATERIALS AND METHODS: A cross-sectional study was conducted at the Fundación Jiménez Díaz University Hospital (May 2021-March 2022) where molecular diagnostic of 537 Formalin-Fixed Paraffin-Embedded (FFPE) tissue samples of diverse solid tumors (lung, colorectal, melanoma, gastrointestinal stromal, among others) was performed using AVENIO Tumor Tissue Targeted Kit. A descriptive analysis of the features of all samples was carried out. Multivariable logistic analysis was conducted to assess the impact of sample characteristics on NGS performance defined by informative results rate (for all tumors and for lung tumors), and on actionable mutations rate (for lung tumors only). RESULTS: AVENIO performance rate was 75.2% in all tumor samples and 75.3% in lung cancer samples, and the multivariable analysis showed that surgical specimens are most likely to provide informative results than diagnostic biopsies. Regarding the mutational findings, 727 pathogenic, likely pathogenic, or variant of unknown significance mutations were found in all tumor samples. Single nucleotide variant was the most common genomic alteration, both for all tumor samples (85.3% and 81.9% for all solid tumors and lung samples, respectively). In lung tumors, multivariable analysis showed that it is more likely to find actionable mutations from non-smokers and patients with adenocarcinoma, large cell, or undifferentiated histologies. CONCLUSION: This is the largest cohort-level study in Spain to profile the analyses of biopsy samples of different tumors using NGS in routine clinical practice. Our findings showed that the use of NGS routinely provides good rates of informative results and can improve tumor characterization and identify a greater number of actionable mutations.

Redefining the high-grade B cell lymphoma with double/triple rearrangements of MYC and BCL2/BCL6 genes. Learning from a case report.

We report a patient initially diagnosed with a triple hit high-grade B cell lymphoma (HGBL-TH), in which further morphologic, immunohistochemical, and next-generation sequencing studies of subsequent specimens disclosed it to be a germinal center diffuse large B cell lymphoma (GC-DLBCL) with BCL2/BCL6 gene translocations, PVT1-deletion, and gain of MYC genes evolving from a previous follicular lymphoma. However, fluorescence in situ hybridization (FISH) studies with the break-apart probe for MYC gene showed a fusion and two separated signals (red and green, respectively) leading to the interpretation of MYC gene translocation and a false diagnosis of a TH-lymphoma, according to the recent WHO classification. Nevertheless, PVT1 deletion plus MYC gain/amplification has been described as a cause of the double-hi transcription profile. These data highlight the need for new criteria to identify these highly aggressive lymphomas.

Comprehensive Approach to Genomic and Immune Profiling: Insights of a Real-World Experience in Gynecological Tumors.

Gynecological cancer accounts for an elevated incidence worldwide requiring responsiveness regarding its care. The comprehensive genomic approach agrees with the classification of certain tumor types. We evaluated 49 patients with gynecological tumors undergoing high-throughput sequencing to explore whether identifying alterations in cancer-associated genes could characterize concrete histological subtypes. We performed immune examination and analyzed subsequent clinical impact. We found 220 genomic aberrations mostly distributed as single nucleotide variants (SNV, 77%). Only 3% were classified as variants of strong clinical significance in BRCA1 and BRCA2 of ovarian high-grade serous (HGSC) and uterine endometrioid carcinoma. TP53 and BRCA1 occurred in 72% and 28% of HGSC. Cervical squamous cell carcinoma was entirely HPV-associated and mutations occurred in PIK3CA (60%), as well as in uterine serous carcinoma (80%). Alterations were seen in PTEN (71%) and PIK3CA (60%) of uterine endometrioid carcinoma. Elevated programmed death-ligand 1 (PD-L1) was associated with high TILs. Either PD-L1 augmented in deficient mis-matched repair (MMR) proteins or POLE mutated cases when compared to a proficient MMR state. An 18% received genotype-guided therapy and a 4% immunotherapy. The description of tumor subtypes is plausible through high-throughput sequencing by recognizing clinically relevant alterations. Additional concomitant assessment of immune biomarkers identifies candidates for immunotherapy.

Validation and clinical application of a targeted next-generation sequencing gene panel for solid and hematologic malignancies.

BACKGROUND: Next-generation sequencing (NGS) is a high-throughput technology that has become widely integrated in molecular diagnostics laboratories. Among the large diversity of NGS-based panels, the Trusight Tumor 26 (TsT26) enables the detection of low-frequency variants across 26 genes using the MiSeq platform. METHODS: We describe the inter-laboratory validation and subsequent clinical application of the panel in 399 patients presenting a range of tumor types, including gastrointestinal (GI, 29%), hematologic (18%), lung (13%), gynecological and breast (8% each), among others. RESULTS: The panel is highly accurate with a test sensitivity of 92%, and demonstrated high specificity and positive predictive values (95% and 96%, respectively). Sequencing testing was successful in two-thirds of patients, while the remaining third failed due to unsuccessful quality-control filtering. Most detected variants were observed in the TP53 (28%), KRAS (16%), APC (10%) and PIK3CA (8%) genes. Overall, 372 variants were identified, primarily distributed as missense (81%), stop gain (9%) and frameshift (7%) altered sequences and mostly reported as pathogenic (78%) and variants of uncertain significance (19%). Only 14% of patients received targeted treatment based on the variant determined by the panel. The variants most frequently observed in GI and lung tumors were: KRAS c.35G > A (p.G12D), c.35G > T (p.G12V) and c.34G > T (p.G12C). CONCLUSIONS: Prior panel validation allowed its use in the laboratory daily practice by providing several relevant and potentially targetable variants across multiple tumors. However, this study is limited by high sample inadequacy rate, raising doubts as to continuity in the clinical setting.

Clinical, genetics and bioinformatics characterization of a campomelic dysplasia case report.

Campomelic dysplasia is a rare disorder characterized by skeletal and extraskeletal defects. Up to two-thirds of affected XY individuals have a gradation of genital defects or may develop as phenotypic females. This syndrome is caused by alterations in SRY-related HMG-Box Gene 9 (SOX9), a transcription factor essential in both chondrocyte differentiation and sex determination. We report a 27-week fetus with ambiguous genitalia and upper and lower extremities bone malformations. Gross photographs, radiologic and pathological studies led the clinical diagnosis to campomelic dysplasia. A new frameshift mutation (p.Pro415Serfs*163) was identified in the SOX9 gene by genetic analysis. This mutation not only alters almost the entire sequence of the C-terminal transactivation (TA) domain of SOX9, but also enlarges it. This altered sequence does not resemble any other existing sequence. Since TA domain is entirely affected, SOX9 could not establish its normal function. The comparison between p.Pro415Serfs*163 and other frameshift mutations that enlarges SOX9 showed the same nucleotides added. This new sequence is not conserved either. We speculate that the fact of adding a sequence downstream of the C-terminal domain alters SOX9 and leads to campomelic dysplasia. The clinical information is essential not only to achieve a correct diagnosis in fetuses with pathologic ultrasound findings, but also to offer a proper genetic counseling.