Update on olfactory neuroblastoma.

Olfactory neuroblastomas are uncommon malignancies that arise from olfactory receptor cells located high in the nasal cavity. Accurate diagnosis plays a crucial role in determining clinical results and guiding treatment decisions. Diagnosis can be a major challenge for pathologists, especially when dealing with tumours with poor differentiation. The discovery of several molecular and immunohistochemical markers would help to overcome classification difficulties. Due to the paucity of large-scale studies, standardisation of diagnosis, treatment and prediction of outcome remains a challenge. Surgical resection by endoscopic techniques with the addition of postoperative irradiation is the treatment of choice. In addition, it is advisable to consider elective neck irradiation to minimise the risk of nodal recurrence. Molecular characterisation will help not only to make more accurate diagnoses but also to identify specific molecular targets that can be used to develop personalised treatment options tailored to each patient. The present review aims to summarise the current state of knowledge on histopathological diagnosis, the molecular biology and management of this disease.

Olfactory neuroblastoma in a domestic cat and review of the literature.

Nasal tumors account for less than 10% of all feline neoplasms, with lymphoma, followed by adenocarcinoma, and squamous cell carcinoma, the most commonly reported. Nasal neuroectodermal tumors, including olfactory neuroblastoma (ONB), are scarcely described, and their tumorigenesis is largely unknown. Here we report the cytological, histological, and immunohistochemical features of a feline ONB. We also provide a pathological review of nasal neuroendocrine neoplasms in cats. A 7-year-old Burmese cat was evaluated for sneezing, occasional epistaxis, and upper respiratory noise for 8 months. Computed tomography (CT) imaging revealed a 7 × 5 × 3 mm irregular mass effacing and expanding the nasal cavity, which extended to the nasopharynx. Cytologically, neoplastic cells were round to polygonal and had a round nucleus with finely stippled chromatin, a single small nucleolus, and abundant pale blue cytoplasm, which contained abundant fine pale pink granules. They exhibited mild cellular atypia, anisocytosis, and mild to occasionally moderate anisokaryosis. Rhinoscopic biopsies revealed a densely cellular, malignant neuroepithelial neoplasm. Cells were arranged in densely packed trabeculae and formed Homer Wright and Flexner-Wintersteiner-like rosettes, with rare mitotic figures and scant supportive fibrovascular stroma. Immunohistochemically, neoplastic cells were positive for vimentin, cytokeratin AE1/AE3, COX-2, and beta-tubulin and negative for S-100, chromogranin A, CD117, and epithelial membrane antigen (EMA). An ONB was diagnosed based on histological and immunohistochemical findings. Interestingly, and similar to nasal carcinomas, neoplastic cells diffusely neo-expressed COX-2. To the authors' knowledge, there is no previous evidence of COX-2 in feline ONB. Histopathology and immunohistochemistry are required for a definitive diagnosis of ONB.

Proceedings of the 2023 North American Society of Head and Neck Pathology Companion Meeting, New Orleans, LA, March 12, 2023: Navigating New Developments in High Grade Sinonasal Neuroendocrine and Neuroectodermal Neoplasms.

Although the definitions of sinonasal neuroendocrine and neuroectodermal neoplasms did not change substantially in the 5th edition WHO Classification of Head and Neck Tumours, the diagnosis of olfactory neuroblastoma (ONB), small cell neuroendocrine carcinoma, and large cell neuroendocrine carcinoma remains quite challenging in practice. Ambiguities surrounding the amount of keratin expression allowable in ONB and the amount of neuroendocrine differentiation seen in sinonasal undifferentiated carcinoma (SNUC) lead to significant diagnostic discrepancies at the high grade end of this tumor spectrum. Furthermore, a group of problematic neuroepithelial tumors that show overlapping features of ONB and neuroendocrine carcinoma have never been recognized in formal classification schemes. Since publication of the 5th edition WHO, two new tumor entities have been proposed that help resolve these problems. Olfactory carcinoma is defined by high grade keratin-positive neuroectodermal cells with frequent intermixed glands and shows recurrent Wnt pathway, ARID1A, and RUNX1 alterations. IDH2-mutant sinonasal carcinoma is a molecularly-defined category that encompasses tumors with undifferentiated (SNUC), large cell neuroendocrine, and neuroepithelial phenotypes. This review will provide a practical overview of these emerging entities and their application to diagnostic challenges in the post-WHO sinonasal neuroendocrine and neuroectodermal tumor classification.

Olfactory Neuroblastoma-A Challenging Fine Line between Metastasis and Hematology.

Developing in a limited space, rare tumors located at the nose and paranasal sinuses are sometimes difficult to diagnose due to their modest clinical presentation, which is uncorrelated with anatomopathological diversity. This limits the preoperative diagnosis without added immune histochemical study; for that reason, we present our experience with these tumors with the intention of raising awareness. The patient included in our study was investigated by our department through clinical and endoscopic examination, imaging investigations, and an anatomic-pathological study. The selected patient gave consent for participation and inclusion in this research study in compliance with the 1964 Declaration of Helsinki.

Olfactory neuroblastoma with rhabdomyoblasts: A rare case report and review of the literature.

Herein we present a case of a 62-year-old male patient who was admitted with the chief complaints of nasal obstruction. The histopathological and immunohistochemical evaluation led to a diagnosis of olfactory neuroblastoma with rhabdomyoblasts. A review of the literature revealed that this is only the fourth case of olfactory neuroblastoma with rhabdomyoblasts. Thus, investigation of more cases and longer follow-up is necessary to understand the disease and identify the best treatment to improve prognosis.

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.

Prognostic significance of PD-1, CTLA-4, CD4, and CD8 expression in olfactory neuroblastoma.

There are limited data regarding immune surveillance mechanisms in olfactory neuroblastoma. We investigated the expression of programmed cell death protein 1 (PD-1), cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), CD4, and CD8 in olfactory neuroblastoma to identify potential therapeutic targets. Immunohistochemistry was used to detect PD-1 and CTLA-4 and measure the numbers of CD4+ and CD8+ T cells in 56 patients with olfactory neuroblastoma. The relationships between these molecules in tumor microenvironment, clinicopathological features, and survival were analyzed. The prevalence of PD-1 in Kadish C stage was 24.14%, significantly greater than in Kadish A and B stage. CD4+ T-cell and CD8+ T-cell levels correlated with higher Hyams histological grade and Kadish stage. In addition, PD-1 was related positively with CTLA-4, CD4+ T cells, and CD8+ T cells in olfactory neuroblastoma. Univariate survival analysis showed that higher PD-1 positivity, CD8+ T cells, and Hyams grade correlated with worse clinical outcome. Multivariate analysis showed that the expression of PD-1 was an independent parameter for poor prognosis. In conclusion, olfactory neuroblastoma with PD-1 expression had more aggressive clinicopathological features and worse prognosis. PD-1 may potentially predict the outcome of olfactory neuroblastoma patients.

Cytological diagnosis of olfactory neuroblastoma at metastatic sites, with emphasis on role of insulinoma-associated protein 1 immunocytochemistry.

BACKGROUND: Olfactory neuroblastoma (ONB) is a rare neuroectodermal tumor with a propensity for lymph node and distant metastases in a proportion of cases, presenting opportunities for cytological diagnosis. Insulinoma-associated protein 1 (INSM1) is a recently identified marker of neuroendocrine differentiation with higher sensitivity and specificity than traditional neuroendocrine immunostains used in diagnosis of ONB. METHODS: Archival aspirates diagnosed as metastatic ONB were retrieved and reviewed for described characteristics of ONB. Spare direct smears with sufficient cellular material from each case were selected, if available, and immunocytochemistry for INSM1 was performed on the destained alcohol-fixed smears. INSM1 was also performed on non-neuroendocrine malignant round cell tumors (MRCT). RESULTS: Seven fine needle aspirates (FNA) from five patients were identified, all of which showed a small round cell tumor with fine to coarse granular chromatin. Most cases had moderate to high cellularity, comprised of loosely cohesive clusters and dispersed cells. While two-cell pattern, nuclear streaking and moulding were frequent, background neuropil, fibrillary cytoplasm, and rosettes were uncommon. INSM1 immunostaining performed on spare direct smears showed strong positivity in 30%-100% of tumor cells (mean: 62%) in all aspirates tested (100%). In comparison with other immunostains, INSM1 showed more robust staining, and was easier to interpret. All non-neuroendocrine MRCTs were negative for INSM1. CONCLUSION: Metatstatic ONB can resemble other small round cell tumors, as all the diagnostic features of ONB may not be readily evident. INSM1 immunocytochemistry has high sensitivity and specificity and can reliably be used as a single marker to support the cytomorphology for a confirmatory diagnosis of ONB, even on direct smears if a cell block is not available.

Olfactory Neuroblastoma: Morphological Reappraisal and Molecular Insights with Quantum Leap in Clinical Perspectives.

PURPOSE OF REVIEW: The purpose of review is to provide a comprehensive review of the literature focusing on the recent advances in the diagnosis, molecular underpinning, and targeted therapy of olfactory neuroblastoma (ONB). RECENT FINDINGS: Studies focused on the molecular fingerprinting of ONB are critical to engage new promising treatment strategies. Molecular-based subtype classifications have been proposed (basal-like ONB and neural-like ONB) but are not widely used. The rationale for implementation of DNA methylation analysis and IDH2 sequencing in routine work-up for ONB is gaining recognition. Expression of somatostatin receptors (SSTR) in ONB open new avenues for both, diagnostic (especially metastatic disease) and new treatment protocols with somatostatin analogs. Olfactory carcinoma is proposed as a unifying diagnostic terminology pertinent to epithelial divergent differentiation in olfactory neuroblastoma. Molecular (genetic and epigenetic) efforts on olfactory neuroblastoma are promising; however further refinement is needed for employment of these biomarkers as clinical standard of care. Ongoing and future multi-institutional collaborative studies will contribute to further understanding of ONB biology and aid the development of targeted treatments for this disease.

Esthesioneuroblastoma presenting as syndrome of inappropriate antidiuretic hormone secretion.

Hyponatremia is the most common fluid electrolyte disorder in hospitalized patients. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the main cause of normovolemic hyponatremia, it can be caused by diverse etiologies: malignant tumors are the most feared cause that clinician persists in finding. Exceptionally, SIADH can complicate Esthesioneuroblastoma (ENB) or olfactory neuroblastoma, a rare tumor of the nasal sinus cavities. We report the case of a 26-year-old female patient admitted for recurrent headaches and vomiting, with a profound normovolemic hyponatremia at the initial assessment. Biological explorations have concluded in a SIADH. Imaging showed a mass of the left nasal cavity with extensions to the ipsilateral paranasal sinuses. The biopsy of the lesion, under endoscopic control, was inconclusive. The anatomopathological study, after surgical removal, concluded in ENB. The postoperative evolution was marked by the normalization of the natremia.

A rare presentation of esthesioneuroblastoma: a case report and review of the literature.

Esthesioneuroblastoma is a rare malignant tumor developing from the olfactory neuroepithelium. It represents less than 5% of all cancers of the nasal cavity. We are going to report the observation of a patient followed at the regional oncology center of Oujda in Morocco who presented a locally advanced esthesioneuroblastoma. Treatment consisted of surgical resection followed by adjuvant radiotherapy on the tumor bed. Currently, the patient is in good control of his disease.

Transcription Factor Expression in Sinonasal Neuroendocrine Neoplasms and Olfactory Neuroblastoma (ONB): Hyams' Grades 1-3 ONBs Expand the Spectrum of SATB2 and GATA3-Positive Neoplasms.

Sinonasal neuroendocrine neoplasms (SN-NENs) are rare and mostly include neuroendocrine carcinoma (NEC), whereas neuroendocrine tumor (NET) is exceptional in this site. Olfactory neuroblastoma (ONB) is a malignant neuroectodermal neoplasm arising in the nasal cavity. Albeit crucial for correct patients' management, the distinction of high grade ONB from NEC is challenging and requires additional diagnostic markers. The transcription factor SATB2 has been recently introduced in routine diagnostics as an immunohistochemical marker of distal intestine differentiation. No specific data are available about SATB2 and GATA3 expression in SN-NENs. GATA3, SATB2, and, for comparison, CDX2 expression were investigated in a series of epithelial and non-epithelial SN-NENs. We collected 26 cases of ONB and 7 cases of epithelial SN-NENs diagnosed and treated in our Institution. ONBs were graded according to Hyams' system and epithelial NENs were reclassified into 5 NECs, 1 MiNEN, and 1 amphicrine carcinoma. Immunohistochemistry was performed using standard automated protocols. Hyams' grades 1-3 ONBs stained diffusely and intensely for SATB2, whereas grade 4 ONBs and NECs were globally negative. The non-neuroendocrine component of MiNEN and the amphicrine carcinoma were strongly positive. GATA3 was heterogeneously and unpredictably expressed in Hyams' grades 1-3 ONBs, whereas grade 4 ONBs and NECs were completely negative. CDX2 was negative in all cases. Our study identifies, for the first time, SATB2 and GATA3 expression as features of Hyams' grades 1-3 ONBs, expands the spectrum of SATB2 and GATA3-positive neoplasms, and suggests that Hyams' grade 4 ONBs are not only clinically but also biologically different from low graded ONBs.

Presentation and Outcomes of Non-Squamous Cell Carcinoma Sinonasal Malignancies: A National Perspective.

BACKGROUND: Non-squamous cell carcinoma sinonasal malignancies (NSCCSM) are relatively rare. Neoadjuvant radiotherapy and/or chemotherapy (NTx) have been proposed to improve outcomes compared to surgery alone. In this study, we aim to examine the prevalence of NTx utilization and associated outcomes. METHODS: A retrospective study utilizing the National Cancer Database, 2004 to 2015. The study population included adult patients diagnosed with primary NSCCSM. RESULTS: A total of 574 patients were included. The mean age of the study population was 61.7 ± 16.5 years. The median follow-up time was 40.4 months (interquartile range: 15.3-81.3 months). The histopathological diagnoses identified included: (i) 37.0% adenocarcinoma, (ii) 22.8% adenoid cystic carcinoma, (iii) 20.0% mucosal melanoma, (iv) 11.9% esthesioneuroblastoma, and (v) 8.2% sinonasal undifferentiated carcinoma (SNUC). NTx was utilized in 70 (12.20%) of the study population. Patients who received NTx were more likely to have SNUC or esthesioneuroblastoma (P < .01 each) and to have stage III or IV disease (P < .01 each). NTx was most likely to be administrated in a high-volume center [OR: 3.94, 95%CI: (1.47, 10.53), P = .006]. Patients who received NTx had a significantly lower prevalence of positive margin postoperatively [OR: 0.48, 95%CI: (0.26, 0.87), P = .016]. In patients with NSCCSM, negative margin was associated with improved overall survival [HR: 0.55, 95%CI: (0.36, 0.82), P = .004]. CONCLUSIONS: This study provides an epidemiological perspective regarding NSCCSM and related practice patterns and survival outcomes. Neoadjuvant radiotherapy and/or chemotherapy is likely to decrease the risk of positive margin which ultimately could improve survival in this population.

Metastatic olfactory neuroblastoma: A small round blue cell puzzle on fine-needle aspiration cytology.

Small round blue cell tumors (SRBCTs) are a heterogeneous group of malignant neoplasms that can be challenging to distinguish on fine-needle aspiration (FNA) cytology. Ancillary tests as well as clinico-radiological correlation are often required to make an accurate diagnosis. FNA is a low-cost, low-infrastructure test, making it a coveted diagnostic tool, especially in low-resource settings. Olfactory neuroblastoma (ONB) is a rare SRBCT encountered in both pediatric and adult patients. Awareness of the cytomorphologic and immunocytochemical features of ONB is important in the workup of a SRBCT. This case report describes the primary diagnosis of metastatic ONB on FNA cytology.

Radiation-Induced Olfactory Neuroblastoma Following Treatment for NK/T-cell Lymphoma, Nasal Type.

Radiation-induced olfactory neuroblastoma (ONB) is an uncommon neoplasm that is generally associated with a poor prognosis. We experienced an unusual case of ONB in a patient who had received previous radiation therapy for extranodal NK/T-cell lymphoma 15 years previously. To our knowledge, this is the first report of a patient with radiation-induced ONB obtaining a complete response (CR) with radical re-irradiation alone. The purpose of this report is to discuss therapeutic strategies for radiation-induced ONB. We report an unusual case of ONB suspected to be a radiation-induced neoplasm in a 33-year-old female who had received 30 Gy of irradiation for extranodal NK/T-cell lymphoma, nasal type (NTCL) 15 years earlier. In this case, the patient presented with nasal obstruction and frequent epistaxis. The patient was diagnosed with ONB based on left nasal biopsy findings. The surrounding normal tissues tolerance of nasal ONB radiation had to be limited, because the previously radiated NTCL was located adjacent to critical organs. We performed intensity modulated radiation therapy (IMRT), which could offer precise irradiation (60 Gy in 2 Gy daily fractions) while sparing critical tissues. The present case was treated with radiation therapy alone, whereas previously reported cases were treated with a combination of chemotherapy and radiation therapy. We treated radiation-induced OBN successfully with radical re-irradiation using IMRT alone and the patient has had no recurrence for 3 years.