Esthesioneuroblastoma: updating histologic grading as it relates to prognosis

Development of an evaluation and treatment strategy for olfactory neuroblastoma: a review of evidence from large-scale studies, including population-based and multicenter studies, and meta-analyses

Olfactory neuroblastoma is a rare sinonasal malignancy arising from the olfactory epithelium that is characterized by skull base involvement and a modest natural history. Because of its rarity and long course, identification of independent prognostic factors is dependent on multivariate analysis of large, long-term data. In this review, we outline evidence for the evaluation and treatment of olfactory neuroblastoma obtained from recent large-scale population-based studies, meta-analyses and multicenter studies. Hyams grade is currently the only pathological grade system for olfactory neuroblastoma. The modified Kadish staging and Dulguerov classification are available for clinical staging. The results of large-scale studies have confirmed Hyams, the modified Kadish and Dulguerov as independent prognostic factors. Surgery followed by radiotherapy provides the best overall survival and recurrence-free survival for resectable disease. The question of whether postoperative radiotherapy should be administered for all cases or only for those at risk of recurrence remains unanswered. Exclusively endoscopic resection is indicated for modified Kadish A/B cases without any increase in the risk of death or recurrence, and is also indicated for modified Kadish C cases if a negative surgical margin is ensured. For more advanced cases, such as those with extensive brain infiltration, the open approach is indicated. Elective nodal irradiation prevents late nodal recurrence of N0 patients. Chemotherapy has failed to show a benefit in survival or disease control. Current needs for olfactory neuroblastoma include the development and validation of refined staging systems suitable for current practice; expansion of indications for endoscopic surgery; less invasive surgery; definitive radiotherapy and novel systemic therapy.

Molecular Evidence for Olfactory Neuroblastoma as a Tumor of Malignant Globose Basal Cells

Olfactory neuroblastoma (ONB, esthesioneuroblastoma) is a sinonasal cancer with an underdeveloped diagnostic toolkit, and is the subject of many incidents of tumor misclassification throughout the literature. Despite its name, connections between the cancer and normal cells of the olfactory epithelium have not been systematically explored and markers of olfactory epithelial cell types are not deployed in clinical practice. Here, we utilize an integrated human-mouse single-cell atlas of the nasal mucosa, including the olfactory epithelium, to identify transcriptomic programs that link ONB to a specific population of stem/progenitor cells known as olfactory epithelial globose basal cells (GBCs). Expression of a GBC transcription factor NEUROD1 distinguishes both low- and high-grade ONB from sinonasal undifferentiated carcinoma, a potential histologic mimic with a distinctly unfavorable prognosis. Furthermore, we identify a reproducible subpopulation of highly proliferative ONB cells expressing the GBC stemness marker EZH2, suggesting that EZH2 inhibition may play a role in the targeted treatment of ONB. Finally, we study the cellular states comprising ONB parenchyma using single-cell transcriptomics and identify evidence of a conserved GBC transcriptional regulatory circuit that governs divergent neuronal-versus-sustentacular differentiation. These results link ONB to a specific cell type for the first time and identify conserved developmental pathways within ONB that inform diagnostic, prognostic, and mechanistic investigation.

Recurrent Esthesioneuroblastoma: Long-Term Outcomes of Salvage Therapy

INTRODUCTION

Esthesioneuroblastoma (ENB) is a rare malignant neoplasm arising from the olfactory epithelium of the cribriform plate. Although survival is excellent with a reported 5-year overall survival (OS) of 82%, recurrence is frequent and occurs in 40-50% of cases. This study investigates the characteristics of ENB recurrence and the subsequent prognosis of patients with recurrence.

METHODS

The clinical records of all patients diagnosed as having ENB with subsequent recurrence at a tertiary hospital from 1 January 1960 to 1 January 2020 were retrospectively reviewed. Overall survival (OS) and progression-free survival (PFS) were reported.

RESULTS

A total of 64 out of 143 ENB patients had recurrences. In total, 45 out of 64 recurrences met the inclusion criteria and were included in this study. From these, 10 (22%) had a sinonasal recurrence, 14 (31%) had an intracranial recurrence, 15 (33%) had a regional recurrence, and 6 (13%) had a distal recurrence. The average interval from initial treatment to recurrence was 4.74 years. There were no differences in rates of recurrence with respect to age, sex, or types of surgery (endoscopic, transcranial, lateral rhinotomy, and combined). The time to recurrence was shorter for Hyams grades 3 and 4 compared to Hyams grades 1 and 2 (3.75 years vs. 5.70 years, p < 0.05). Patients with recurrence limited to the sinonasal region had a lower overall primary Kadish stage compared to recurrences beyond the sinonasal region (2.60 vs. 3.03, p < 0.05). A total of 9 (20%) out of 45 patients developed secondary recurrence. Following recurrence, the subsequent 5-year OS and PFS were 63 and 56%, respectively. The mean time to secondary recurrence after treatment of the primary recurrence was 32 months, which was significantly shorter than the time to primary recurrence (32 months vs. 57 months, p = 0.048). The mean age of the secondary recurrence group is significantly older than the primary recurrence group (59.78 years vs. 50.31 years, p = 0.02). No statistically significant differences were observed between the secondary recurrence group and the recurrence group in terms of their overall Kadish stages or Hyams grades.

CONCLUSIONS

Following an ENB recurrence, salvage therapy appears to be an effective therapeutic option with a subsequent 5-year OS of 63%. However, subsequent recurrences are not infrequent and may require additional therapy.

Immunohistochemical Profiling and Staging in Esthesioneuroblastoma: A Single-Center Cohort Study and Systematic Review

OBJECTIVE

Esthesioneuroblastoma (ENB) is a rare sinonasal malignant neoplasm with 40% 5-year survival. Because of the rarity of the tumor, the optimal treatment and subsequent prediction of prognosis are unclear. We studied a modern series of patients with ENB to evaluate the association of immunohistochemical (IHC) markers and clinical stages/grades with outcomes.

METHODS

A single-center retrospective review of patients with ENB treated during a 25-year period was performed. A systematic literature review evaluating the prognostic benefits of current staging systems in evaluating survival outcomes in ENB was undertaken.

RESULTS

Among 29 included patients, 25 (85%) were treated surgically at our institution, with 76% of those endoscopically resected; 7 (24.1%) received chemotherapy, and 18 (62.1%) received radiation therapy. The 5-year overall survival (OS) was 91.3%, and 10-year OS was 78.3%. Progression-free survival at 5 and 10 years was 85.6% and 68.2%, respectively. A total of 36 distinct IHC markers were used to diagnose ENB but were inconsistent in predicting survival. A systematic literature review revealed predictive accuracy for OS using the Kadish, TNM, and Hyams staging/grading systems was 68%, 42%, and 50%, respectively.

CONCLUSIONS

This study reports the 5- and 10-year OS and progression-free survival in a modern series of patients with ENB. No traditional IHC marker consistently predicted outcome. Some novel reviewed markers show promise but have yet to enter clinical mainstream use. Our systematic review of accepted staging/grading systems also demonstrated a need for further investigation due to limited prognostic accuracy.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Nasal Cavity, Paranasal Sinuses and Skull Base

The World Health Organization Classification of Head and Neck Tumours recently published the 5th edition. There are new entities, emerging entities, and significant updates to the taxonomy and characterization of tumor and tumor-like lesions, specifically in this article as it relates to nasal cavity, paranasal sinuses and skull base. Importantly, the number of diagnostic entries has been reduced by creating category-specific chapters for soft tissue, hematolymphoid, melanocytic, neuroectodermal, and metastatic tumors. Bone and salivary gland tumors are also not separately reported in the sinonasal tract, but included in the jaw and salivary gland sections, respectively. Repetition of characteristic entities in each anatomic site was also reduced, instead highlighting only the unique features in each anatomic site. Two new entities (SWI/SNF complex-deficient sinonasal carcinomas and HPV-related multiphenotypic sinonasal carcinoma) will be highlighted in this review, with a discussion of several emerging entities. There is a short description of updated information for all 24 diagnostic entities included in this edition to allow the reader a snapshot of current state of knowledge, but to encourage more investigation and further broaden understanding of these diverse and rare entities.

Emerging concepts in sinonasal tumor research

PURPOSE OF REVIEW

Sinonasal malignancies are rare and understudied, often diagnosed at late stages, and may behave aggressively. This review explores investigative diagnostic, therapeutic, and scientific advances specific to sinonasal undifferentiated carcinoma (SNUC), intestinal-type adenocarcinoma (ITAC), and olfactory neuroblastoma (ONB).

RECENT FINDINGS

A number of studies have recently contributed more robust knowledge of the genetic and molecular landscapes of SNUC, ITAC, and ONB. These analyses have identified SMARCB1 and IDH2 mutations in SNUC, potentially allowing for the tumor's subdivision. Recent studies have also defined a role for induction chemotherapy in SNUC. Somatic mutations for ITAC have been identified and may be potentially targetable with FDA approved therapies. Studies defining the tumor microenvironment for ITAC and ONB have introduced the possibility of immune checkpoint inhibition for these tumor types.

SUMMARY

Studies reviewed here detail promising results of the most current and novel characterization of SNUC, ITAC, and ONB genetic and molecular landscapes, which have informed ongoing therapeutic discovery. With continued multi-institutional efforts, the field of sinonasal tumor research will achieve higher disease control and improved treatment outcomes for patients afflicted with these rare cancers.

Regional Recurrences and Hyams Grade in Esthesioneuroblastoma

Objective  The aim of this study is to determine if Hyams grade may help predict which patients with esthesioneuroblastoma (ENB) tumors are likely to develop regional recurrences, and to determine the impact of tumor extent on regional failure in ENB patients without evidence of nodal disease at presentation. Design  The study was designed as a retrospective review for ENB patients. Settings  The study was prepared at tertiary care academic center for ENB patients. Participants  Patients with ENB were included in the study. Main Outcome Measures   Oncologic outcomes (5-year regional and locoregional control (LRC) and overall survival) in patients with Hyams low grade versus high grade. Oncologic outcomes based on radiographic disease extent. Results  A total of 43 patients were included. Total 25 patients (58%) had Hyams low-grade tumor, and 18 (42%) had high-grade tumor. Of the 34 patients without regional disease at presentation, 8 (24%) were treated with elective nodal radiation. There were no statistically significant differences in 5-year regional control in the Hyams low-grade versus high-grade groups (78 vs. 89%; p  = 0.4). The 5-year LRC rates in patients with low grade versus high grade were 73 versus 89% ( p  = 0.6). The 5-year overall survival rates in patients with low-grade versus high-grade tumors were 86 versus 63% ( p  = 0.1). Radiographic extension of disease into the olfactory groove, olfactory nerve, dura, and periorbita were statistically associated with decreased 5-year overall survival (5-year OS 49 vs. 91% [ p  = 0.04], 49 vs. 91% [ p  = 0.04], 44 vs. 92% [ p  = 0.02], and 44 vs. 80% [ p  = 0.04], respectively). Conclusion  ENBs are associated with a risk of regional failure. The current analysis suggests that Hyams low-grade and high-grade malignancies have comparable rates of early and delayed regional recurrences, although small sample size may limit our conclusions.

Esthesioneuroblastoma in children, adolescents and young adults

The esthesioneuroblastoma (ENB) is characterized as a rare malignant sinonasal tumor of neuroectodermal origin. Its starting point is the olfactory epithelium located in the upper part of the nasal cavities. Different nomenclatures have been proposed, but the most common are "esthesioneuroblastoma" and "olfactory neuroblastoma". ENBs have a bimodal distribution and mainly occur in teenagers, young adults and people aged 50-60. It is a very rare tumor in pediatrics since only around 100 cases have been reported so far. Within ENBs, we can distinguish tumors with different biological behavior ranging from localized forms with slow evolution to aggressive and metastatic forms at onset. In addition, precisely diagnosing undifferentiated tumors and distinguishing them from other etiologies of sinonasal tumors are sometime difficult. Added to its very low incidence, these characteristics make the study of ENB complicated. The standard treatment currently includes broad surgery followed by radiation therapy in localized resectable tumors. Neoadjuvant chemotherapy is indicated in large unresectable tumors and in metastatic forms. However, in certain indications, such as high-grade operable tumors, the role of perioperative chemotherapy remains to be defined. The objective of this analysis is to detail current knowledge regarding ENBs' epidemiological, biological, clinical and radiological characteristics as well as how to manage ENB in young patients.

Extensive tumor calcification in response to pre-operative reductive chemotherapy in pediatric esthesioneuroblastoma: a case report

Esthesioneuroblastomas are uncommon tumors in pediatric patients and are typically treated with multimodal therapy. Changes in gross tumor quality and character in response to adjuvant treatment have not been clearly reported. We report the case of a 15-year-old female with a diagnosis of Kadish stage C esthesioneuroblastoma who was treated with neoadjuvant chemotherapy and surgical resection. The patient's tumor demonstrated cytoreduction after chemotherapy but also was found to have calcified. A combined trans-frontal sinus craniotomy with endoscopic endonasal resection was performed and resulted in negative margins and good clinical outcome.

ICAR: endoscopic skull-base surgery

BACKGROUND

Endoscopic skull-base surgery (ESBS) is employed in the management of diverse skull-base pathologies. Paralleling the increased utilization of ESBS, the literature in this field has expanded rapidly. However, the rarity of these diseases, the inherent challenges of surgical studies, and the continued learning curve in ESBS have resulted in significant variability in the quality of the literature. To consolidate and critically appraise the available literature, experts in skull-base surgery have produced the International Consensus Statement on Endoscopic Skull-Base Surgery (ICAR:ESBS).

METHODS

Using previously described methodology, topics spanning the breadth of ESBS were identified and assigned a literature review, evidence-based review or evidence-based review with recommendations format. Subsequently, each topic was written and then reviewed by skull-base surgeons in both neurosurgery and otolaryngology. Following this iterative review process, the ICAR:ESBS document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:ESBS document addresses the role of ESBS in primary cerebrospinal fluid (CSF) rhinorrhea, intradural tumors, benign skull-base and orbital pathology, sinonasal malignancies, and clival lesions. Additionally, specific challenges in ESBS including endoscopic reconstruction and complication management were evaluated.

CONCLUSION

A critical review of the literature in ESBS demonstrates at least the equivalency of ESBS with alternative approaches in pathologies such as CSF rhinorrhea and pituitary adenoma as well as improved reconstructive techniques in reducing CSF leaks. Evidence-based recommendations are limited in other pathologies and these significant knowledge gaps call upon the skull-base community to embrace these opportunities and collaboratively address these shortcomings.

Evaluating the prognostic potential of the Ki67 proliferation index and tumour-infiltrating lymphocytes in olfactory neuroblastoma

AIMS

Olfactory neuroblastomas (ONBs) are rare malignant tumours that arise in the nasal vault. To date, the Hyams grade remains the only widely used histological grading system. However, it is based only on morphological criteria, and has not been updated since 1988. The objective of this study was to explore the prognostic potential of the Ki67 proliferation index (PI) and tumour-infiltrating lymphocytes (TILs) in ONB.

METHODS AND RESULTS

A retrospective study was conducted on a bicentric series of 45 cases. The Ki67 PI was determined by counting at least 1000 nuclei on whole slides. TILs were evaluated with CD20, CD4 and CD8 immunohistochemical markers on whole slides. In this series, Hyams grades I, II, III and IV accounted for 13.4%, 44.4%, 20% and 22.2% of all cases, respectively. The Ki67 PI ranged from 1 to 93; the Ki67 PI was significantly higher in Hyams grade III-IV ONBs than in Hyams grade I-II ONBs (P < 0.0001). A Ki67 PI of ≥25 was associated with poorer survival (P = 0.02). TILs were present in both stromal and intratumoral compartments, but were located predominantly in the stromal component of the tumour. The numbers of intratumoral CD8+ cells/mm² and CD4+ cells/mm² were greater in high-grade ONBs than in low-grade ONBs (P = 0.0015 and P = 0.043, respectively). The numbers of T cells/mm² and B cells/mm² were not associated with survival, but a CD4/CD8 ratio of >2 was significantly associated with shorter survival (P = 0.04).

CONCLUSION

Our findings suggest that the Ki67 PI and TILs could be used as prognostic markers, as a potential alternative to the Hyams grade.

[Neuroendocrine neoplasms of the auditory, olfactory, and visual sensory organs]

Neuroendocrine neoplasms (NENs) are infrequent in sensory organs. There are well-differentiated neuroendocrine neoplasms that should be classified as neuroendocrine tumors, in analogy to their gastrointestinal counterparts, however the nomenclature is inconsistent. The best defined entities are neuroendocrine tumors in the middle ear and ectopic pituitary adenoma in the sphenoid region. Poorly differentiated NENs most often arise in the olfactory organ and nasal cavity that are represented by olfactory neuroblastomas and poorly differentiated neuroendocrine carcinomas. They have several mimickers such as the sinonasal undifferentiated carcinoma, poorly differentiated squamous cell carcinoma, mucosal malignant melanoma, rhabdomyosarcoma, Ewing sarcoma/primitive neuroectodermal tumor and non-Hodgkin lymphoma.

Hyams grading as a predictor of metastasis and overall survival in esthesioneuroblastoma: a meta-analysis

BACKGROUND

Esthesioneuroblastoma (ENB), also known as olfactory neuroblastoma, represents up to 3% of all sinonasal neoplasms. Hyams histologic grading is a promising tool in predicting metastases and establishing prognoses for this complex tumor.

METHODS

A systematic literature search was performed in the PubMed, Ovid MEDLINE, and Cochrane databases. ENB patients with Hyams I-II or III-IV were categorized as low-grade Hyams (LGH) or high-grade Hyams (HGH), respectively. Binary and continuous random-effects models were applied to calculate odds ratios (ORs) for the incidences of neck and distal metastases as well as for 5- and 10-year overall survival rates.

RESULTS

Of the 57 screened articles published from 1993 to 2018, 16 (525 patients) and 21 (563 patients) provided data for tumor metastases and overall survival rates, respectively. Neck metastasis was observed in 18.2% of HGH vs 7.9% of LGH patients. Distant metastasis was noted in 20.7% of HGH vs 8.9% of LGH patients. LGH patients had 5- and 10-year overall survival rates of 81.2% and 64.0%, respectively, as compared with 60.9% and 40.6%, respectively, for HGH patients. In comparing HGHs vs LGHs, the collective ORs for neck and distant metastases were 2.08 (95% confidence interval [CI], 1.09-3.99; p = 0.03) and 2.37 (95% CI, 1.07-5.26; p = 0.03), respectively. Moreover, in comparing LGHs vs HGHs, collective ORs for 5- and 10-year overall survival rates were 3.39 (95% CI, 2.09-5.49; p < 0.001) and 3.03 (95% CI, 1.82-5.06; p < 0.001), respectively.

CONCLUSION

HGH ENBs, compared with LGH ENBs, are more likely to metastasize to neck or distal targets and to have lower overall survival rates.

Ectopic primary olfactory neuroblastoma of the nasopharynx: A case report and review of the literature

Olfactory neuroblastoma (ONB, also called esthesioneuroblastoma) is a rare malignant tumor of neuroectodermal olfactory cells. We report a case of an undifferentiated ONB with unfavorable histology arising ectopically in the nasopharynx. The patient was a 15-year-old male who presented with a right-sided painful neck mass, nasal obstruction, and weight loss. Awareness of the ectopic ONBs, although exceedingly rare, is important when considering differential diagnoses of sinonasal tumors as treatment and prognosis may differ from other lesions.

Olfactory Neuroblastoma

PURPOSE OF REVIEW

To provide a comprehensive review of the literature focusing on the recent advances in the diagnosis and management of olfactory neuroblastoma.

RECENT FINDINGS

Multimodality treatment is usually recommended for the majority of ONB cases. Recent advances in surgical approaches include the evolving role of endonasal endoscopic surgical resection and reconstruction. The introduction of new conformal radiation techniques has improved the outcomes and reduced treatment-related toxicity to important structures such as the eye and the brain. The role of neoadjuvant and adjuvant chemotherapy is yet to be defined. In the last two decades, there have been advances in surgical techniques with endoscopic approaches, either alone or in combination with craniotomy, gradually replacing the open traditional approaches. Prolonged surveillance is recommended for ONB due to late recurrences associated with that tumor. The role of chemotherapy and elective neck irradiation is still controversial and needs more studies to investigate their optimal role.

Genetic and molecular alterations in olfactory neuroblastoma: implications for pathogenesis, prognosis and treatment

Olfactory neuroblastoma (ONB, Esthesioneuroblastoma) is an infrequent neoplasm of the head and neck area derived from olfactory neuroepithelium. Despite relatively good prognosis a subset of patients shows recurrence, progression and/or metastatic disease, which requires additional treatment. However, neither prognostic nor predictive factors are well specified. Thus, we performed a literature search for the currently available data on disturbances in molecular pathways, cytogenetic changes and results gained by next generation sequencing (NGS) approaches in ONB in order to gain an overview of genetic alterations which might be useful for treating patients with ONB. We present briefly ONB molecular pathogenesis and propose potential therapeutic targets and prognostic factors. Possible therapeutic targets in ONB include: receptor tyrosine kinases (c-kit, PDGFR-b, TrkB; EGFR); somatostatin receptor; FGF-FGFR1 signaling; Sonic hedgehog pathway; apoptosis-related pathways (Bcl-2, TRAIL) and neoangiogenesis (VEGF; KDR). Furthermore, we compare high- and low-grade ONB, and describe its frequent mimicker: sinonasal neuroendocrine carcinoma. ONB is often a therapeutic challenge, so our goal should be the implementation of acquired knowledge into clinical practice, especially at pretreated, recurrent and metastatic stages. Moreover, the multicenter molecular studies are needed to increase the amount of available data.

Comprehensive Molecular Profiling of Olfactory Neuroblastoma Identifies Potentially Targetable FGFR3 Amplifications

Olfactory neuroblastomas (ONBs), also known as esthesioneuroblastomas, are malignant round-cell tumors that represent up to 5% of sinonasal malignancies. Despite their aggressive course, molecular studies of ONBs have been limited, and targeted therapies are lacking. To identify potential oncogenic drivers and targetable pathways in ONBs, we characterized 20 ONBs, including archived ONBs profiled by targeted, multiplexed PCR (mxPCR)-based DNA next-generation sequencing (NGS) of the coding sequence of over 400 cancer-relevant genes (n = 16), mxPCR-based RNA NGS of 108 target genes (n = 15), and 2 ONBs profiled by comprehensive hybrid-capture-based clinical grade NGS of >1,500 genes. Somatic mutations were infrequent in our cohort, with 7 prioritized nonsynonymous mutations in 5 of 18 (28%) ONBs, and no genes were recurrently mutated. We detected arm/chromosome-level copy-number alterations in all tumors, most frequently gains involving all or part of chromosome 20, chromosome 5, and chromosome 11. Recurrent focal amplifications, often but not exclusively in the context of arm-level gains, included CCND1 [n = 4/18 (22%) tumors] and the targetable receptor tyrosine kinase FGFR3 [n = 5/18 (28%) tumors]. Targeted RNA NGS confirmed high expression of FGFR3 in ONB (at levels equivalent to bladder cancer), with the highest expression observed in FGFR3-amplified ONB cases. Importantly, our findings suggest that FGFR3 may be a therapeutic target in a subset of these aggressive tumors.Implications: ONBs harbor recurrent chromosomal copy-number changes, including FGFR3 amplification associated with overexpression. Hence, FGFR3 may represent a novel therapeutic target in these tumors. Mol Cancer Res; 15(11); 1551-7. ©2017 AACR.

Small round blue cell tumors of the sinonasal tract: a differential diagnosis approach

One of the most challenging diagnostic categories within tumors of the sinonasal tract is the small round blue cell tumors. Biopsies are usually small and limited, resulting in considerable diagnostic difficulty for practicing surgical pathologists. These tumors share several overlapping histologic and immunophenotypic findings while also showing considerable variation within and between cases. Specific tumor site of origin, imaging findings, and clinical findings must be combined with the histology and pertinent ancillary studies if the correct diagnosis is to be reached. Discrimination between neoplasms is critical as there are significant differences in therapy and overall outcome. It is important to have a well developed differential diagnosis for this category of tumors, where each of the diagnoses is considered, evaluated, and either confirmed or excluded from further consideration. In an undifferentiated tumor, showing a small round blue cell morphology, using the mnemonic 'MR SLEEP' helps to highlight tumors to consider: melanoma, mesenchymal chondrosarcoma, rhabdomyosarcoma, sinonasal undifferentiated carcinoma, squamous cell carcinoma (including NUT carcinoma), small cell osteosarcoma, lymphoma, esthesioneuroblastoma (olfactory neuroblastoma), Ewing sarcoma/primitive neuroectodermal tumor, pituitary adenoma, and plasmacytoma. A panel of pertinent immunohistochemistry studies, histochemistries and/or molecular tests should aid in reaching a diagnosis, especially when taking the pattern and intensity of reactions into consideration.

Clinical characteristics of infant neuroblastoma and a summary of treatment outcome

Neuroblastoma (NB) is the most common malignant solid tumor in the peripheral nervous system in infants and young children, with a high degree of malignancy. The clinical characteristics and prognosis of NB in infants are unique. The present study retrospectively analyzed the prognosis of infant NB cases that underwent different treatments. In total, 16 infant NB cases (10 male and 6 female) who were treated between February 2007 and August 2013 in Beijing Tongren Hospital (Beijing, China), were enrolled in the study. They were diagnosed by pathology, medical imaging and serology methods. These 16 patients were subjected to comprehensive treatment, including chemotherapy, surgery, autologous peripheral blood stem cell transplantation (APBSCT) and radiation therapy. The age distribution and clinical stages were: 5 cases (31.25%) at ≤3 months (4 cases at stage 4s and 1 case at stage 4); 2 cases (12.5%) at 3-6 months (both at stage 4s); and 9 cases (56.25%) at 6-12 months (2 cases at stage 4s, 6 cases at stage 4 and 1 case at stage 3). Subsequent to treatment, nicotinic acid esterase (NSE) levels in the patient's serum significantly decreased. The NSE levels in 12 cases (75%) dropped to the reference value (0-15.2 ng/dl). All the NB infants at stages 4s and 3 were treated by surgery and chemotherapy (100%; 9/9). The 5 NB infants at stage 4 were treated by chemotherapy and surgery. For the 2 NB infants who experienced recurrence or whose condition was partially relieved after conventional therapy, APBSCT therapy was applied. At the last follow-up in September 2014, 13 cases (81.25%) presented with a complete response, 2 cases (12.50%) with a partial response and 1 case (6.25%) with recurrence after transplantation (progressive disease). In conclusion, infant NB cases are sensitive to chemotherapy, particularly the cases at stage 4s, which occur with a higher incidence, but with a better clinical response and prognosis after treatment.

Imaging of Paranasal Sinuses and Anterior Skull Base and Relevant Anatomic Variations

This article reviews the normal anatomy and variants of the anterior skull base and sinonasal cavities that are relevant to endoscopic sinus and skull base surgery. Radiologists should be aware of sinonasal anatomy that can be impediments to surgical access and increase risk of vascular or cranial nerve injury during surgery. Imaging features of the paranasal sinuses and anterior skull base pathologies are also discussed.

Sensitizing acute myeloid leukemia cells to induced differentiation by inhibiting the RIP1/RIP3 pathway

Tumor necrosis factor-α (TNF-α)-induced RIP1/RIP3 (receptor-interacting protein kinase 1/receptor-interacting protein kinase 3)-mediated necroptosis has been proposed as an alternative strategy for treating apoptosis-resistant leukemia. However, we found that most acute myeloid leukemia (AML) cells, especially M4 and M5 subtypes, produce TNF and show basal level activation of RIP1/RIP3/MLKL signaling, yet do not undergo necroptosis. TNF, through RIP1/RIP3 signaling, prevents degradation of SOCS1, a key negative regulator of interferon-γ (IFN-γ) signaling. Using both pharmacologic and genetic assays, we show here that inactivation of RIP1/RIP3 resulted in reduction of SOCS1 protein levels and partial differentiation of AML cells. AML cells with inactivated RIP1/RIP3 signaling show increased sensitivity to IFN-γ-induced differentiation. RIP1/RIP3 inactivation combined with IFN-γ treatment significantly attenuated the clonogenic capacity of both primary AML cells and AML cell lines. This combination treatment also compromised the leukemogenic ability of murine AML cells in vivo. Our studies suggest that inhibition of RIP1/RIP3-mediated necroptotic signaling might be a novel strategy for the treatment of AML when combined with other differentiation inducers.

[Esthesioneuroblastoma: A single institution's experience and general literature review]

PURPOSE

Olfactory neuroblastoma or esthesioneuroblastoma is a rare entity among head and neck neoplasms. In this paper, we report the experience of our institution and compare it with a comprehensive review of the literature.

PATIENTS AND METHODS

We retrospectively analysed clinical and treatment data of patients referred to the Lyon Sud University Hospital (France) for histologically proven olfactive esthesioneuroblastoma.

RESULTS

Ten patients treated between 1993 and 2015 have been analysed. Disease stage at diagnosis, according to the Kadish staging system, was C in 90% of cases. Median follow-up was 136 months. Ten-year overall survival was 90%. Five- and ten-year progression-free survival were 70% and 50%. Nine patients (90%) underwent surgical resection first. Seven of the nine patients who underwent resection (77%) received adjuvant three-dimensional (3D)-conformal radiotherapy (n=7), intensity-modulated radiotherapy (n=1), or volumetric arctherapy (n=1). The mean dose to the tumour volume was 61Gy. None of the patients received elective nodal irradiation. Two patients received concurrent chemotherapy. Five patients (50%) presented with disease recurrence, which was local (n=1), nodal (n=2) and cerebral (n=2).

CONCLUSION

Our results are consistent with the literature. Because of the lack of prospective study and the low number of cases in the literature, each institution's experience is of the utmost important to improve standardised management of these tumours.

Prognosis and biology in esthesioneuroblastoma: the emerging role of Hyams grading system

Esthesioneuroblastoma is a sinonasal tumor with distinct clinicopathologic features, multiple facets, and a spectrum of behavior. Characterization of this disease is challenging, and clinically, several staging systems have been used with no consensus on a single scheme. Recently, the Hyams histological grading system has emerged as a promising prognostication tool that offers an added value to stage. This review addresses prognosis and biology in esthesioneuroblastoma. More specifically, we sought to present a critical appraisal on the value of each of these stratification systems, stage vs. grade, in identifying risk groups and guiding management.