Recurrent USP6 rearrangement in a subset of atypical myofibroblastic tumours of the soft tissues: low-grade myofibroblastic sarcoma or atypical/malignant nodular fasciitis?

AIMS: Low-grade myofibroblastic sarcoma (LGMS) is a rarely metastasizing myofibroblastic tumour mostly affecting extremities and the head and neck of adults. Histologically, it shows long infiltrative fascicles of spindle cells with moderate nuclear atypia. By immunohistochemistry, it stains positive for smooth muscle actin (SMA) and sometimes for desmin. To date, no recurrent genetic abnormalities have been described. Ubiquitin-specific peptidase 6 (USP6) gene rearrangement is typically found in some benign bone and soft-tissue tumours including nodular fasciitis (NF), among others. Nevertheless, rare cases of USP6-rearranged tumours resembling NF with atypical features have been reported. METHODS AND RESULTS: One index case of LGMS of the deltoid in a 56-year-old man presented the THBS2::USP6 translocation by RNA sequencing (Archer FusionPlex Sarcoma v2 panel). Further screening of 11 cases of LGMS using fluorescent in situ hybridization (FISH) analysis with a USP6 break-apart probe identified two additional cases. These cases were investigated with RNA-sequencing, and a RRBP1::USP6 translocation was detected in one. The other case was not assessable because of low-quality RNA. Noteworthy, rearranged LGMSs presented distinctive features including variable multinodular/plexiform architecture, prominent vasculature with occasional wall thickening, scattered osteoclast-like multinucleated giant cells, and peripheral lymphoid aggregates. CONCLUSION: Our findings support the notion that among soft-tissue neoplasms with fibroblastic/myofibroblastic phenotype, USP6 rearrangement is not limited to benign tumours, and warrants further investigation of genetic changes in myofibroblastic sarcomas.

Sinonasal nodular fasciitis: report of a case with USP6 rearrangement.

Nodular fasciitis (NF) is a benign myofibroblastic proliferation characterized by rapid growth, a self-limiting course, and USP6 gene rearrangement. Although it can arise in the head and neck region, very few cases of NF involving the sinonasal tract have been reported to date. Herein we report a case of NF involving the nasal cavity presenting as a polypoid well-defined mass causing obstructive symptoms in a male with a history of multiple local surgeries. Although the mass had an unusual clinical presentation, the histopathologic and immunohistochemical findings were consistent with NF. Fluorescent in situ hybridization performed with break-apart probes flanking the USP6 locus on chromosome 17p13 revealed the presence of USP6 gene rearrangement. The patient remained free of disease 124 months after surgical treatment. Considering its remarkably benign behavior despite its alarming clinical and histologic features, the distinction of NF from sinonasal malignant tumors is essential.

The Histological Background of Recurrence in Laryngeal Squamous Cell Carcinoma: An Insight into the Modifications of Tumor Microenvironment.

Recurrent laryngeal carcinoma presents differences from the primary tumor that largely depend on the treatment. In this article, we review the histologic and molecular treatment-induced changes that may affect the diagnosis of recurrent laryngeal carcinoma, the assessment of predictive markers, and the response to treatment with immune checkpoint inhibitors. Radiotherapy induces profound modifications that are strictly related to necrosis of different tissue components, fibrosis, and damage of the tumor vessels. Postradiotherapy recurrent/persistent laryngeal squamous cell carcinoma typically presents a discohesive growth pattern within a fibrotic background associated with significant changes of the tumor immune microenvironment, with both important immunosuppressive and immunostimulatory effects. Overall, the increase of immunoregulatory cells and immune checkpoints such as CTLA-4, TIM-3, PD-1, and PD-L1 induced by radiotherapy and chemotherapy strongly supports the use of immune checkpoint inhibitors in recurrent/persistent laryngeal carcinoma. Future studies aiming to identify predictive factors of the response to immune checkpoint inhibitors should consider such treatment-induced modifications.

High proportion of inflammatory CD62Llow eosinophils in blood and nasal polyps of severe asthma patients.

BACKGROUND: In mice models, eosinophils have been divided into different subpopulations with distinct phenotypes and functions, based on CD62L and CD101 patterns of membrane expression. Limited data are available in humans. OBJECTIVE: To investigate eosinophils subpopulations in peripheral blood (PB) and nasal polyp tissue (NP) from severe eosinophilic asthma (SEA) patients plus concomitant chronic rhinosinusitis with nasal polyps (CRSwNP). METHODS: We recruited 23 SEA patients (14 with CRSwNP); as controls, we enrolled 15 non-severe asthma patients, 15 allergic rhinitis patients without asthma and 15 healthy donors. Eosinophils were isolated from PB and NP and analysed by FACS. Eotaxin-3 and eotaxin-1 mRNA expression in NP tissue was also evaluated. RESULTS: A significantly higher percentage of circulating CD62Llow cells was observed in SEA, as compared with controls, expressing higher levels of CCR3, CD69 and lower levels of CD125 (IL-5R), CRTH2, CD86 and CD28 in comparison with CD62Lbright cells. In NP, eosinophils showed a high proportion of CD62Llow phenotype, significantly greater than that observed in PB. Surface expression of IL-3R, IL-5R, CD69 and CD86 was significantly higher in CD62Llow eosinophils from NP than in those from blood. Moreover, eotaxin-3 mRNA expression positively correlated with the percentage of CD62Llow cells in NP. CONCLUSION: Two different eosinophil subphenotypes can be identified in blood and NP of SEA patients, with a preferential accumulation of CD62Llow inflammatory cells in NP.

Alteration of the Nucleotide Excision Repair (NER) Pathway in Soft Tissue Sarcoma.

Clinical responses to anticancer therapies in advanced soft tissue sarcoma (STS) are unluckily restricted to a small subgroup of patients. Much of the inter-individual variability in treatment efficacy is as result of polymorphisms in genes encoding proteins involved in drug pharmacokinetics and pharmacodynamics. The nucleotide excision repair (NER) system is the main defense mechanism for repairing DNA damage caused by carcinogens and chemotherapy drugs. Single nucleotide polymorphisms (SNPs) of NER pathway key genes, altering mRNA expression or protein activity, can be significantly associated with response to chemotherapy, toxicities, tumor relapse or risk of developing cancer. In the present study, in a cohort of STS patients, we performed DNA extraction and genotyping by SNP assay, RNA extraction and quantitative real-time reverse transcription PCR (qPCR), a molecular dynamics simulation in order to characterize the NER pathway in STS. We observed a severe deregulation of the NER pathway and we describe for the first time the effect of SNP rs1047768 in the ERCC5 structure, suggesting a role in modulating single-stranded DNA (ssDNA) binding. Our results evidenced, for the first time, the correlation between a specific genotype profile of ERCC genes and proficiency of the NER pathway in STS.

Low levels of miR-34c in nasal washings as a candidate marker of aggressive disease in wood and leather exposed workers with sinonasal intestinal-type adenocarcinomas (ITACs).

INTRODUCTION: Sinonasal intestinal-type adenocarcinomas (ITACs) are rare and aggressive tumors, closely related to professional exposure to wood dusts or leather. Here we explored the role of non-coding RNAs controlling MUC2 in liquid biopsies and tumors from ITAC patients with the aim of identifying biomarkers and molecular mechanisms to improve early diagnosis, prognosis, and therapeutic approaches for this rare cancer. METHODS: MiR-34c-3p, lncRNA AF147447 and MUC2 were measured in tumors and normal mucosa, in nasal washings (NW) from the affected and non-affected nostril and in plasma from 17 ITAC patients. The Apparent Diffusion Coefficient (ADC) was also evaluated by Magnetic Resonance Imaging. RESULTS: MiR-34c was higher in ITACs compared to the corresponding normal mucosa (p = 0.021). Differentiated tumors exhibited higher miR-34c levels (p = 0.025) and lower ADC values (p<0.001) compared to mucinous ones and these parameters were also inversely correlated (r = 0.87; p = 0.001). High MUC2 tumor expression was associated with orbital extension (p = 0.010). Low miR-34c levels in NW were associated with orbital (p = 0.009) and intracranial (p = 0.031) extension and with advanced TNM stage (p = 0.054). Functional analysis identified Wnt, Focal adhesion, MAPK and inflammatory signalings among the pathways most enriched in mir-34c targets. DISCUSSION: Our results suggest measuring miR-34c in NW as a biomarker for early diagnosis and monitoring of ITAC patients and for the surveillance of wood and leather exposed workers. Further research on the involvement of miR-34c regulated pathways in ITAC tumorigenesis may also allow the development of new therapeutic approaches for this rare cancer.

Estimating survival after salvage surgery for recurrent salivary gland cancers: Systematic review.

Recurrent salivary gland carcinomas (RSCs) are poorly characterized and their clinical features and treatment options have not yet been fully described. The goal of this study was to analyze the therapeutic strategies and oncological outcomes of RSC patients through a literature review analysis. This systematic review was performed according to the PRISMA statements. Inclusion criteria for the systematic review were based on the population, intervention, comparison, and outcomes according to (PICO) framework. Two thousand seven hundred and four records were selected and 1817 recurrences were studied. Three hundred and sixty-five patients underwent salvage surgery (20.1%) and their 5-year mortality rate, overall survival and disease-free survival were 35%, 70%, and 42%, respectively. RSCs are aggressive neoplasms with a high rate of distant metastases (28.9%). Salvage surgery can be considered in patients with limited local and/or regional recurrences, even in case of single distant relapse, appearing within the first 3 years of follow-up.

Durvalumab with cetuximab and radiotherapy for locally advanced squamous cell carcinoma of the head and neck: A phase 1/2 trial.

BACKGROUND AND PURPOSE: To report on the anti-tumor activity of a novel combination in high-risk locally advanced head and neck squamous cell carcinoma. MATERIALS AND METHODS: At a fixed dose of 1500 mg every 28 days, anti PD-L1 Durvalumab was given concomitantly to Radiotherapy and Cetuximab starting from the first week of combined treatment, followed by adjuvant Durvalumab to a maximum of 6 months after completion of radiation. The primary endpoint of the study was 2-year progression-free survival (PFS). A safety run-in was planned. Due to regulatory issues which prevented from opening multiple centers, COVID-19 pandemic and withdrawal of Durvalumab from supporting company, the study was prematurely terminated in April 2021. RESULTS: Between July 2019 and August 2020, 9 patients were enrolled in the study. All tumors had a PD-L1 Combined Positive Score > 1. Optimal drug exposure was observed, with mean relative dose intensity of 85.5% and 87.5% for Cetuximab and Durvalumab, respectively. No radiation breaks were necessary. A grade 4 mucositis lasting for 14 days corresponded to the only dose limiting toxicity we reported. At a median follow-up of 11.5 months (IQR 7.7-16.7) all surviving patients (6 out of 9) are disease-free, with 1 and 2-year PFS rates of 77.7% and 58.3%, respectively. A selective sparing of node levels in the elective volume was performed in all cases, yielding a cumulative mean dose of 37.6 Gy (SD 8.4). CONCLUSION: Albeit limited by the small sample size, our preliminary observation of anti-tumor activity and tolerability of Durvalumab in addition to Cetuximab and radiation may warrant further investigations.

Stereotactic Body Radiotherapy in Oligomestatic/Oligoprogressive Sarcoma: Safety and Effectiveness Beyond Intrinsic Radiosensitivity.

BACKGROUND: Metastatic soft tissue sarcoma (STS) patients may benefit from local ablative treatments due to modest efficacy of systemic chemotherapy. However, use of stereotactic body radiotherapy (SBRT) is controversial because of presumed radioresistance of STS. METHODS: Patients treated with SBRT for oligometastatic and oligoprogressive metastatic STS were retrospectively reviewed to assess results in terms of local control (LC), disease-free survival (DFS), and overall survival (OS). Incidence and grade of adverse events were reported. Statistical analysis was performed to identify variables correlated with outcome and toxicity. RESULTS: Forty patients were treated with SBRT to a median biologic effective dose (BED) of 105 (66-305) Gy5 to 77 metastases. Two-year LC, DFS, and OS were 67%, 23%, and 40%. Improved LC was shown in patients receiving a BED >150 Gy5 (hazard ratio [HR], 3.9; 95% confidence interval [CI], 1.6-9.7; P = 0.028). A delay >24 months between primary tumor diagnosis and onset of metastases was associated with improved DFS (HR, 0.46; 95% CI, 0.22-0.96; P = 0.01) and OS (HR, 0.48; 95% CI, 0.23-0.99; P = 0.03). No toxicity grade ≥3 was observed. CONCLUSIONS: Stereotactic body radiotherapy is effective in metastatic STS with a benign toxicity profile. A BED >150 Gy5 is required to maximize tumor control rates. Metastatic relapse >24 months after diagnosis is correlated to improved survival.

Ewing family tumors of the appendicular skeleton: a retrospective analysis of prognostic factors.

PURPOSE: Authors retrospectively analyzed possible prognostic factors in a series of patients affected by Ewing sarcoma of extremities (eEWS) and treated over a 20-year period at a single institution. METHODS: Between 1997 and 2017, 88 bone eEWS were treated at our institution. Staging, age, gender, tumoral volume, local treatment, surgical margins, post-ChT necrosis were investigated for prognostic correlation with overall survival (OS) and event-free survival (EFS). Median follow-up was 74 months (1-236). RESULTS: Staging of disease correlated with OS (81% vs 59%, p = 0.01) and not with EFS (68% vs 57%, p = 0.28) in localized vs metastatic eEWS at presentation. Age ≥ 14 years (p = 0.002) and volume ≥ 100 cm3 (p = 0.04) were significant negative prognostic factors. No difference was found in local treatment: OS was 76% vs 63% (p = 0.33), while EFS was 68% vs 49% (p = 0.06) after surgery alone or surgery + radiotherapy, respectively. Regarding surgical margins, OS was 76% vs 38% (p = 0.14), and EFS was 65% vs 33% (p = 0.14) in adequate vs not adequate, respectively. OS was 86% and 68% in good and poor responders, respectively (p = 0.13). CONCLUSION: In eEWS, metastatic disease at presentation, age > 14 years and tumoral volume > 100 cm3 are negative prognostic factors. Intensified adjuvant ChT can improve prognosis in poor responders and metastatic patients.

MUC4 is a valuable marker for distinguishing secretory carcinoma of the salivary glands from its mimics.

AIMS: Secretory carcinoma (SC) (synonym: mammary analogue secretory carcinoma) is a low-grade salivary gland tumour that occurs in both major and minor salivary glands. SC is known for its wide morphological, architectural and immunohistochemical spectrum, which overlaps with those of several salivary gland neoplasms, including acinic cell carcinoma (AciCC) and intercalated duct-type intraductal carcinoma (IDC) in major salivary glands, and polymorphous adenocarcinoma (PAC) in minor salivary glands. These tumours share with SC some morphological features and SOX10 immunoreactivity; also, with the exception of AciCC, they all coexpress S100 and mammaglobin. METHODS AND RESULTS: We compared MUC4 and mammaglobin expression in 125 salivary gland carcinomas (54 genetically confirmed SCs, 20 AciCCs, 21 PACs, and 30 IDCs) to evaluate the potential of these two markers to differentiate these entities. Moderate to strong diffuse MUC4 positivity was detected in 49 SCs (90.7%), as compared with none of the IDCs and PACs. In contrast, mammaglobin was frequently expressed in SCs (30 of 36 cases; 83.3%), IDCs (24/28; 85.7%), and PACs (7/19; 36.8%). Two of three high-grade SCs lost MUC4 expression in the high-grade tumour component. No significant correlation was found between MUC4 expression and the fusion variant in SC (ETV6-NTRK versus non-ETV6-NTRK). CONCLUSION: The results of our study identify MUC4 as a sensitive (90.7%) and specific (100%) marker for SC, with high positive (100%) and negative (93.4%) predictive values. Thus, MUC4 may be used as a surrogate for SC in limited biopsy material and in cases with equivocal morphology.

TRPA1 Expression in Synovial Sarcoma May Support Neural Origin.

Synovial sarcoma (SS) is a malignant mesenchymal soft tissue neoplasm. Despite its name, the cells of origin are not synovial cells, but rather neural, myogenic, or multipotent mesenchymal stem cells have been proposed as possible cells originators. Unlike other sarcomas, an unusual presentation of long-term pain at the tumor site has been documented, but the exact mechanisms have not been fully clarified yet. The transient receptor potential ankyrin 1 (TRPA1) is a nonselective cation channel mainly expressed in primary sensory neurons, where it functions as a pain sensor. TRPA1 have also been described in multiple non-excitable cells, including those derived from neural crest stem cells such as glial cells and, in particular, Schwann cell oligodendrocytes and astrocytes. We evaluated TRPA1 expression in SS. We selected a cohort of 41 SSs, and by immunohistochemistry, we studied TRPA1 expression. TRPA1 was found in 92.6% of cases. Triple TRPA1/pS100/SOX10 and TRPA1/SLUG/SNAIL staining strongly supports a neural origin of SS. TRPA1 positivity was also observed in a subset of cases negative with pS100, SOX10 and/or SLUG/SNAIL, and these divergent phenotypes may reflect a process of tumor plasticity and dedifferentiation of neural-derived SSs. Given the functional diversity of TRPA1 and its expression in neuronal and non-neuronal multipotent neural crest stem cells, it remains to be determined whether TRPA1 expression in SSs neoplastic cells plays a role in the molecular mechanism associated with premonitory pain symptoms and tumor progression.

Re-irradiation for oligoprogression under Nivolumab in recurrent head and neck squamous cell carcinoma: A case report.

Immune checkpoint inhibitors (ICIs) represent a recently introduced class of agents active in head and neck squamous cell carcinoma (HNSCC). For a subgroup of patients with recurrent or metastatic disease, long-term benefit can be achieved: maintaining a sustained response to immunotherapy is therefore a critical factor for its efficacy at an individual level. In analogy to targeted agents, a limited pattern of progression, or "oligoprogression", can occur. For locally recurrent HNSCC, the potential biologic interplay between the efficacy of ICIs and the design of radiation fields chosen for primary treatment is currently unknown. Here, we report on a patient who presented two subsequent oligoprogressions successfully treated with re-irradiation without interrupting Nivolumab. Both oligoprogressive lesions developed in previously unirradiated areas. We hypothesize the existence of a synergistic effect with optimal spatial cooperation between ICIs and re-irradiation for oligoprogressive disease under immunotherapy.

The natural history of epithelioid sarcoma. A retrospective multicentre case-series within the Italian Sarcoma Group.

INTRODUCTION: This case-series is aimed to describe the natural history of epithelioid sarcoma (ES) and to provide insights into the differential clinical behaviour of its two variants ("classic-type" and "proximal-type"). The value of a subtype-adapted grading system based on pathological features is explored. METHODS: Data from consecutive, primary, localised, INI1-deleted ES operated at three Italian sarcoma reference centres (1995-2015) were included. Centralised pathological review was performed. Classic-type ES was broken down into "high-grade" and "low-grade", according to number of mitoses, evidence of necrosis and nuclear atypia. Five- and 10-year overall survival (OS) and crude cumulative incidence (CCI) of local recurrence (LR) and distant metastasis (DM) were estimated. RESULTS: Fifty-two patients were included. 5- and 10-year OS estimates were 70% and 47% in the whole series, 57% and 37% in patients with proximal-type ES, 77% and 54% in patients with classic-type ES (P = 0.02). In classic-type ES, 5- and 10-year OS was higher for low-grade (95% and 72%, respectively) than high-grade tumours (P = 0.002). 5- and 10-year CCI estimates for LR were 21% and 33% in the whole series. 5- and 10-year CCI estimates for DM were 35% and 39% in the whole series, both 28% in classic-type ES, 47% and 59% in proximal-type ES (P = 0.03). CONCLUSIONS: Suffering from a proximal- or a classic-type is the stronger predictor of outcome in patients with localised ES, with proximal-type ES patients having lower survival due to a higher tendency toward metastatic spreading. However, the "high-grade" classic-type ES was associated with outcomes close to proximal-type ES.

Intestinal metaplasia of the sinonasal mucosa adjacent to intestinal-type adenocarcinoma. A morphologic, immunohistochemical, and molecular study.

It has been hypothesized that the development of sinonasal intestinal-type adenocarcinoma (ITAC) occurs through intestinal metaplasia (IM) of the respiratory and/or glandular epithelium. The aim of this study was to characterize the histological, immunohistochemical, and molecular features of sinonasal IM. Histologic slides from 29 consecutive surgical specimens of ITAC were retrieved. Sections were stained for CDX2, cytokeratin 20 (CK20), MUC2, and p53. The status of TP53 gene exons 4-9 was assessed separately in areas of IM and in ITAC. Foci of IM were detected in eight cases (27.5%). They were all positive for CK20 and CDX2, while MUC2 was detected in six cases (75%). In six cases (75%), the metaplastic foci showed signs of dysplasia, including nuclear enlargement with increased nucleus to cytoplasm ratio, nuclear hyperchromasia, loss of nuclear polarity, and presence of prominent nucleoli. P53 nuclear immunoreactivity was observed in four cases. TP53 gene sequencing was successfully performed in six cases and revealed the same mutation in both IM and ITAC in two cases (c.832C > T and c.215G > C), while another ITAC showed a mutation that was not present in the adjacent IM (c.536A > G). In conclusion, our study suggests a possible clonal relationship between areas of sinonasal IM and ITAC, indicating that IM may represent a precursor lesion of ITAC. Improving the knowledge on the morphological and molecular features of IM is a key step to identify reliable biomarkers to determine the risk of sinonasal ITAC development.

Primary combined neuroendocrine and squamous cell carcinoma of the maxillary sinus: report of a case with immunohistochemical and molecular characterization.

Neuroendocrine neoplasms represent a rare subset of tumors in the sinonasal tract. Combined tumors, with an endocrine and a non-neuroendocrine component, are exceedingly rare, and mainly consist of a combination of neuroendocrine carcinoma with adenocarcinomas. We present the clinico-pathologic and immunohistochemical features of a neuroendocrine carcinoma combined with squamous cell carcinoma, arising in the maxillary sinus. In addition, we evaluated the clonal origin of the two components through analysis of TP53 gene status. Both components were positive for cytokeratins AE1/AE3, while the squamous cell carcinoma was positive for cytokeratin 5/6 and p63, and the neuroendocrine carcinoma showed immunoreactivity for neuron specific enolase, chromogranin, synaptophysin and CD56. In situ hybridization for human papilloma virus and Epstein-Barr virus were negative in both components. A missense mutation in TP53 exon 7 (c.734G>C) and strong nuclear immunostaining for p53 were detected only in the neuroendocrine carcinoma. This suggests that the tumor either derived from one precursor cell with squamous differentiation, which underwent TP53 mutation and acquisition of a neuroendocrine phenotype, or it derived from two separate clones, one with mutated TP53 and neuroendocrine differentiation, and the other with wild type TP53 and squamous differentiation (collision tumor).

Diagnostic utility of PLAG1 immunohistochemical determination in salivary gland tumors.

PLAG1 (pleomorphic adenoma gene 1) is a proto-oncogene whose overexpression is a crucial oncogenic event in salivary gland pleomorphic adenomas (PA), and in carcinoma ex-PA. The aim of the present study is to evaluate the sensitivity and the specificity of PLAG1 as a marker in the differential diagnosis of salivary gland benign and malignant tumors. We examined 101 cases, including 36 PAs, 8 myoepitheliomas, 3 basal cell adenomas, and 1 canalicular adenoma among benign tumors; 16 mucoepidermoid carcinomas, 10 adenoid cystic carcinomas, 8 acinic cell carcinomas, 8 polymorphous low-grade adenocarcinomas, 7 salivary duct carcinoma, and 4 epithelial-myoepithelial carcinoma among malignant tumors. PLAG1 was diffusely positive in 94.4% of PAs and in all myoepitheliomas, although with a lower staining intensity. Among malignant tumors, 2 (25%) polymorphous low-grade adenocarcinomas and 1 salivary duct carcinoma ex-PA were positive. In conclusion, PLAG1 is a marker with good specificity for PA and could be a useful diagnostic adjunct in the diagnosis of salivary gland tumors. In particular, this marker is negative in the most common salivary carcinomas, including adenoid cystic carcinoma, mucoepidermoid carcinoma, and acinic cell carcinoma. However, some mimickers of PA, like polymorphous low-grade adenocarcinoma, may show occasional positivity for PLAG1, thus limiting its diagnostic use. In addition, carcinoma ex-PA shows consistent positivity, and therefore should be considered as a diagnostic possibility in case of a malignant tumor with PLAG1 expression.

Low prevalence of K-RAS, EGF-R and BRAF mutations in sinonasal adenocarcinomas. Implications for anti-EGFR treatments.

We have previously shown that a subset of sinonasal intestinal-type adenocarcinomas (ITAC) shows activation of the epidermal growth factor-receptor (EGFR) pathway. In this study we examine the status of the EGFR, KRAS and BRAF genes in a series of sinonasal intestinal (ITAC) and non-intestinal type adenocarcinomas (non-ITAC). Eighteen ITACs and 12 non-ITACs were studied immunohistochemically for EGFR expression. Point mutations were analyzed for EGFR exons 19 and 21, KRAS exon 2 and BRAF exon 15 by direct sequencing. Non-ITACs showed significantly higher expression of EGFR (p = 0.015). Mutation analysis revealed one ITAC with EGFR and one ITAC with KRAS mutation, while two non-ITACs presented mutation of BRAF. We conclude that a subset of sinonasal adenocarcinomas shows overexpression of EGFR, while activating mutations of the signaling cascade downstream of EGFR are rare, suggesting that these tumors could be good candidates for anti-EGFR therapies.

Primary juxtacortical myoepithelioma/mixed tumor of the bone: a report of 3 cases with clinicopathologic, immunohistochemical, ultrastructural, and molecular characterization.

We describe the clinicopathological, immunohistochemical, and molecular features of 3 primary juxtacortical myoepithelioma/mixed tumor of bone. The patients were 2 males (13 and 23 years of age) and a 15-year-old female. The juxtacortical lesions were all located in the femur, and were surgically removed, 2 with wide margins and one with marginal margins. This latter tumor recurred locally 18 months later. The 3 patients were free of disease at 6 to 17 months follow-up. Histologically, all lesions showed a prominent multinodular architecture, and were formed by epithelioid and stellate elements, organized in solid sheets, or embedded in myxoid or chondroid matrix. Areas of osteoid formation were also observed. One tumor had the appearance of classical mixed tumor, showing aspects of duct formation and focal squamous differentiation. Immunohistochemically, all cases were positive for cytokeratins, epithelial membrane antigen, and S100 protein. The expression of other myoepithelial markers, including p63, glial fibrillary acid protein and calponin was more limited. No rearrangement of Ewing sarcoma region 1 (EWSR1) and fused in sarcoma (FUS) genes was observed by fluorescent in situ hybridization. To our knowledge, this is the first report of primary myoepitheliomas of bone arising at juxtacortical sites. These lesions must be distinguished from other benign and malignant bone and cartilage-forming surface tumors, including periosteal chondroma and chondrosarcoma, juxtacortical chondromyxoid fibroma, and periosteal and paraosteal osteosarcoma. The clinicoradiologic presentation and their histological and immunohistochemical features are distinctive enough to allow the separation from these entities.

Immunohistochemical investigation of tumorigenic pathways in sinonasal intestinal-type adenocarcinoma. A tissue microarray analysis of 62 cases.

AIMS: Sinonasal intestinal-type adenocarcinoma (ITAC) is an uncommon neoplasm morphologically similar to colorectal adenocarcinoma, with a well-recognized association with occupational exposure to wood or leather dusts. Here, we analyse several gene products with pivotal roles in tumorigenesis, including p53, p16, deleted in colon cancer (DCC), retinoblastoma, adenomatous polyposis coli, ß-catenin, E-cadherin and CD10, and discuss their relation to clinical behaviour and to similar pathways in colorectal adenocarcinomas. METHODS AND RESULTS: Immunohistochemical analysis of 62 ITACs was conducted on a tissue microarray. Aberrant expression of p53 and p16 were the most commonly observed alterations (61.3% and 64.5% of cases, respectively). Analysis according to the histological subtype showed that p53 overexpression was less frequent in mucinous ITACs (35.3% versus 71.1%, P = 0.018), while loss of DCC and E-cadherin were observed more frequently in this subtype (76.5% versus 31.1%, P=0.002 and 82.4% versus 31.1%, P<0.001, respectively). No correlation was found between the aberrant expression of these and clinical behaviour while mucinous adenocarcinomas had a significantly worse prognosis, with shorter disease-free interval and overall survival (P=0.005 and P<0.001, respectively). CONCLUSIONS: Mucinous ITACs appear to follow a distinct molecular pathway(s) from the non-mucinous variants, and pursue an aggressive clinical behaviour.