Neuroendocrine neoplasms of the head and neck: some suggestions for the new WHO classification of head and neck tumors

Head and Neck Fine Needle Aspiration: Current and Future Impact on Patient Care

The discovery of multiple novel biomarkers in head and neck tumors has led to an increasing interest in utilizing head and neck cytology material as the primary specimens for testing diagnostic and prognostic biomarkers. Although human papillomavirus and programmed death ligand 1 are the most well-established biomarkers tested in cytology specimens, their utilization in cytology is limited by the absence of standardized protocols for specimen collection and fixation. This has led to a quest for innovative techniques to explore the genomic landscape in head and neck tumors and its application in cytology.

Middle ear neuroendocrine tumor with multiple brain metastases: a case report and literature review

Middle ear neuroendocrine tumor (MeNET) is a low-grade tumor with rare recurrence or metastasis. Here, we describe the case of a 29-year-old man who suffered from MeNET that recurred 3 times over 10 years and eventually metastasized to the brain. The patient was treated with surgical resection, radiotherapy, and chemotherapy. However, the tumor was not entirely removed as the brain metastatic tumor adhered tightly to the brainstem. Due to tumor rupture and bleeding after multiple brain tumor removal, profound coma developed. Finally, the patient died 10 months after the last surgery. To our knowledge, this is the first report of a MeNET case with multiple brain metastases. Characteristics of the present case indicate that CK, SYN, increased Ki67 index, and ATRX may be potential biomarkers of invasive MeNET. The survival of patients with brain metastatic MeNET may be extended by surgical resection, radiotherapy, and chemotherapy. Close follow-up of distinctive metastases and biomarkers related to recurrence is also suggested.

Primary Small Cell Neuroendocrine Carcinoma of nasopharynx with metastatic cervical lymph nodes: an exceedingly rare entity with review of literature

Small cell neuroendocrine carcinoma of nasopharynx is extremely rare and displays aggressive nature with a poor prognosis. Neuroendocrine tumours rarely arise from the head and neck region and pose a diagnostic and management challenge. In English literature, only 16 cases of primary small cell neuroendocrine carcinoma of nasopharynx have been reported so far; and to the best of our knowledge, this is the seventeenth case and second in the younger age group. Here, we report the case of an adolescent male patient who presented with nasal blockage, repeated episodes of epistaxis and neck swellings. After proper diagnostic workup, the diagnosis of small cell neuroendocrine carcinoma of nasopharynx was made. The patient was treated with chemotherapy, followed by radiotherapy. Imaging investigation executed after the end of the treatment exhibited complete remission of the disease. The patient is kept under active surveillance with no signs of relapse at present.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumours: Tumours of the Ear

In the recently published 5th Edition of the World Health Organisation Classification of Head and Neck Tumours, there are relatively few changes to report in terms of nomenclature in lesions of ear and temporal bone and fewer developments in molecular pathogenesis in comparison to other sites, particularly in sinonasal tract. Ear and temporal bone tumours are rare and biopsy material is limited. As a result, resources in the literature are scarce with few large series, no controlled clinical trials and the approaches to staging and management are not standardised. New entities are difficult to characterise. The number of entries has, however, increased for tumours of the ear and temporal bone (thirteen) compared to the 4th Edition (eleven). Some lesions previously included in the 4th Edition considered to have no site-specific features have been excluded to be discussed elsewhere and other benign lesions that are specific to this site have been included. The tumours and tumour-like entities of ear and temporal bone are discussed here mindful that the chapter in the 5th edition better correlates disease processes with clinical information and imaging and as far as possible standardises nomenclature.

HPV-related head and neck cancers: Pathology and biology

Discovering the key role HPV plays in head and neck carcinogenesis has revolutionized our approach to cancers such as oropharyngeal carcinomas. As the role of HPV expands beyond the oropharynx, there is a pursued need to understand the oncogenic mechanisms of HPV-driven tumorigenesis and their implications. Optimizing HPV detection methods all while acknowledging their limitations will ensure our ability to diagnose HPV-driven neoplasia wherever clinically relevant.

Malignant Sinonasal Tumors: Update on Histological and Clinical Management

Tumors of nasal cavity and paranasal sinuses (TuNSs) are rare and heterogeneous malignancies, presenting different histological features and clinical behavior. We reviewed the literature about etiology, biology, and clinical features of TuNSs to define pathologic features and possible treatment strategies. From a diagnostic point of view, it is mandatory to have high expertise and perform an immunohistochemical assessment to distinguish between different histotypes. Due to the extreme rarity of these neoplasms, there are no standard and evidence-based therapeutic strategies, lacking prospective and large clinical trials. In fact, most studies are retrospective analyses. Surgery represents the mainstay of treatment of TuNSs for small and localized tumors allowing complete tumor removal. Locally advanced lesions require more demolitive surgery that should be always followed by adjuvant radio- or chemo-radiotherapy. Recurrent/metastatic disease requires palliative chemo- and/or radiotherapy. Many studies emphasize the role of specific genes mutations in the development of TuNSs like mutations in the exons 4-9 of the TP53 gene, in the exon 9 of the PIK3CA gene and in the promoter of the TERT gene. In the near future, this genetic assessment will have new therapeutic implications. Future improvements in the understanding of the etiology, biology, and clinical features of TuNSs are warranted to improve their management.

Application of INSM1 in Diagnosis and Grading of Laryngeal Neuroendocrine Carcinoma

OBJECTIVE

Chromogranin (CHG), synaptophysin (Syn), and CD56 are generally used in a panel to support diagnoses of laryngeal neuroendocrine carcinomas (NECs). However, the absence of expression of these markers does not completely exclude the diagnosis. INSM1 is a novel marker that is considered sufficiently sensitive and specific for NE differentiation. The aim of this study is not only to detect its sensitivity and specificity, but also to evaluate its application in grading for laryngeal NECs.

METHODS

The clinicopathological characteristics of the 25 cases with laryngeal NECs were retrospectively analyzed. The expressions of INSM1, CHG, Syn, and CD56 were detected by immunohistochemistry.

RESULTS

Of the 25 laryngeal NECs, INSM1 had higher sensitivity (92%) than Syn (84%), CHG (76%) and CD56 (76%). The average H scores of INSM1, CD56, Syn, and CHG were 160, 37.5, 300, 300 for well-differentiated neuroendocrine carcinoma (WD-NEC); 190, 149, 209, 215 for moderately differentiated neuroendocrine carcinoma (MD-NEC); 251, 208, 104, 25 for poorly differentiated neuroendocrine carcinoma with small cell (SCNEC); 109, 160, 98, 26 for large cell types (LCNEC), respectively. Of these 98 non-neuroendocrine tumors, INSM1 expression was seen in nine (9%) tumors, all were squamous cell carcinoma. And INSM1 staining was generally focal.

CONCLUSION

INSM1 has high sensitivity and specificity in diagnosis of laryngeal NECs. For grading laryngeal NECs, Syn and CHG showed significant advantages in the diagnosis of WD-NEC and MD-NEC, whereas INSM1 and CD56 showed greater diagnostic value in the diagnosis of SCNEC and LCNEC, especially in SCNEC.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

A Rare Case of Locally Advanced Recurrent Neuroendocrine Tumour of Neck Salvaged by a Radical Surgical Approach

Neuroendocrine tumours of head and neck are rare neoplasms and even more rare are those of cutaneous adenoid cystic carcinoma with neuroendocrine differentiation. Virtually every known variant of neoplasia with neuroendocrine differentiation can arise in complex structures of head and neck (Mills in Endocr Pathol 7(4):329-343. doi:10.1007/BF02739841) [1]. Such tumours are usually non functional, locally aggressive and may spread to lymph nodes or lungs. They are diagnosed by histopathology, immunohistochemistry and radionuclide imaging. When these tumours involve the carotid artery, they pose challenges in the surgical management.

Primary carcinoid tumor in the external auditory canal

A 39-year-old man visited the department of otolaryngology due to an ongoing hearing disturbance that had lasted for 1 year. Temporal bone computed tomography revealed soft tissue density nearly obliterating the left external auditory canal (EAC). The mass was composed of sheets of round tumor cells containing moderate amounts of fine granular cytoplasm and salt and pepper chromatin. Neither mitosis nor necrosis was found. The Ki-67 proliferation index was less than 2%. Cells were positive for CD56 and synaptophysin but negative for chromogranin, cytokeratin (CK) 20, and CK7. Based on these findings, the tumor was diagnosed as a carcinoid tumor, well differentiated neuroendocrine carcinoma, grade 1 (G1) according to current World Health Organization (WHO) classification of head and neck tumors; and a neuroendocrine tumor, G1 according to neuroendocrine neoplasm (NEN)-2018 WHO standard classification. He remained free of local recurrence and metastasis after 20 months of follow up. To date, only six cases of primary NENs in the EAC have been reported. Metastatic tumor should be included in the differential diagnoses. Because of its rarity, the prognosis and treatment have not yet been clarified.

Poorly differentiated neuroendocrine carcinoma of the head and neck: human papillomavirus tumour status/p16 status and impact on overall survival

AIMS

Poorly differentiated neuroendocrine carcinoma (PDNEC) of the head and neck is a rare high-grade neuroendocrine neoplasm. Human papillomavirus (HPV) status and p16 status are as yet unclear among PDNECs, owing to a lack of statistical analysis. The objective of the present study was therefore to evaluate their potential clinicopathological associations, and their prognostic impact on overall survival in PDNECs of the head and neck, regardless to HPV genotype.

METHODS AND RESULTS

All cases of PDNEC of the head and neck between 1998 and 2019 were identified from the database of the Lyon university hospital pathology department (n = 21); for these cases, p16 immunohistochemistry and HPV in-situ hybridisation were performed. Published cases of PDNEC of the head and neck with assessment of HPV status and p16 status were identified in PubMed (n = 57). Local and published cases were pooled for analysis. HPV positive (HPV+) tumour status was found to be significantly associated with oropharyngeal localisation (P < 0.001) and overexpression of p16 (P < 0.001). Multivariate analysis, adjusted on tumour site, histological subtype, p16 status, HPV status, and source of the case, showed that oropharyngeal localisation [hazard ratio (HR) 3.031, 95% confidence interval (CI) 1.257-7.310] and being a small-cell variant (HR 2.859, 95% CI 1.150-7.109) were significant predictors of worse overall survival; HPV+ tumour status was associated with better overall survival (HR 0.388, 95% CI 0.146-0.995).

CONCLUSIONS

HPV+ tumour status was associated with oropharyngeal PDNECs and with a better prognosis.

Carcinoid Tumor Arising from the Sphenoid Sinus Treated with Definitive Intensity-modulated Radiation Therapy: A Case Report

Head and neck neuroendocrine tumors (NET) are a rare type of cancer. NET can be classified according to the histopathological features. The typical carcinoid tumor is a well-differentiated tumor that is the least common among other types. Owing to its indolent behavior and variable radiological and pathological features, treatment of carcinoid tumors remains a challenge. We report a case of a 54-year-old man presenting with a non-operable carcinoid tumor arising in the sphenoid sinuses treated with radiotherapy with stable disease control after three years follow-up.

Recurrent Adenomatous Neuroendocrine Tumor of the Middle Ear: A Diagnostic Challenge

Middle ear adenomatous neuroendocrine tumor (MEANT) poses a diagnostic challenge. Clinical symptoms are nonspecific. Definite diagnosis is made by histopathological analysis of the tumor after a complete surgical resection based on an extensive computed tomography/magnetic resonance imaging (CT/MRI). Controversial terminology of the neoplasm arises from the differentiation of this tumor composed of both endocrine and exocrine glands. Middle ear (ME) localization is rare and less aggressive than gastrointestinal tract or lung localizations. Nevertheless, clinical and CT/MRI analyses are necessary follow-ups for preventing or detecting recurrence or metastasis. A case of a female patient aged 26 with recurrent middle ear neuroendocrine adenoma is presented herein.

Successful cisplatin-etoposide chemotherapy-based treatment of a primary small cell neuroendocrine carcinoma of the tonsil with multiple metastases: a case report

Extrapulmonary small cell neuroendocrine carcinoma (SNEC) is an extremely rare and highly malignant tumor with a poor prognosis. Multiple metastases of SNEC are even more rare, and patients with locally advanced and metastatic disease generally face a poor outcome. To date, only a few cases of SNEC have been reported. Here, we describe a rare case of a 70-year-old female patient with SNEC of the tonsil who presented with multiple metastases and had achieved a complete response (CR) of the primary lesion and cervical lymph nodes for more than 1 year after receiving palliative chemotherapy. Initially, the patient presented with a 2-month history of throat pain. Magnetic resonance imaging and computed tomography revealed a soft mass with moderate enhancement on the left tonsil, which was confirmed by incisional aspiration biopsy. She was additionally sent for a positron emission tomography scan to evaluate small metastases in the left cervical lymph node, right lung, multiple mediastinal lymph nodes, and the fourth lumbar (L4) vertebra body metastases. Histopathological examination of the SNEC confirmed a nested, typical endocrine appearance with small round cells containing ovoid-shaped nuclei and high mitotic activity. Immunohistochemically, the tumor cells were positive for cytokeratin 8/18+, synaptophysin+, CD56+, and Ki-67 (<50%). The patient received 6 cycles of cisplatin combined with etoposide and was subsequently placed under close observation (<12 months). To date, she has achieved a CR of the primary lesion and cervical lymph nodes. In summary, we have described a case of successful treatment after chemotherapy for SNEC and have elucidated professional knowledge regarding the relevant aspects of SNEC.

The clinicopathological spectrum of olfactory neuroblastoma and sinonasal neuroendocrine neoplasms: Refinements in diagnostic criteria and impact of multimodal treatments on survival

OBJECTIVES

To provide a comprehensive review of the clinical and histopathological features of olfactory neuroblastoma (ONB) and other sinonasal neuroendocrine neoplasms (NENs), in order to refine diagnostic criteria, analyze treatment outcomes, and identify prognostic factors.

METHODS

Data from an Italian multi-institutional database were analyzed. Patients were treated surgically via a minimally-invasive endoscopic approach followed by adjuvant radiotherapy or radiochemotherapy. Neoadjuvant cisplatin/etoposide chemotherapy was administered in cases of poorly-differentiated tumors. A centralized pathology review was performed in all cases. Patients were prospectively observed for survival. Overall (OS) and Disease-free survival (DFS) estimates were determined from Kaplan-Meier analysis and compared using the log-rank test. Statistically significant variables were entered in a multivariate Cox regression model.

RESULTS

98 patients with a median follow-up of 53months were included. Morphology review and the incorporation of cytokeratin 8/18 in the immunohistochemical panel modified the final diagnosis in 8/98 (8.2%) cases. The neoplasms were ultimately classified into four groups with different immunohistochemical profiles and clinical behaviors: ONB in 67 cases (5-year-OS, 91.6%); NEC (poorly-differentiated neuroendocrine carcinoma) in 22 cases (5-year-OS, 42.6%); MiNEN (mixed neuroendocrine/non-neuroendocrine neoplasm) in five cases (5-year-OS, 0%,0/5 cases); and NET (well-differentiated neuroendocrine tumor) in four cases (5-year-OS, 50%, 2/4 cases). Hyams grade and Ki67 index were independent prognostic factors for ONB. Neoadjuvant chemotherapy appeared to be associated with improved OS and DFS for NEC, independent of other clinicopathological variables.

CONCLUSIONS

Induction chemotherapy improves survival outcomes in patients affected by poorly-differentiated tumors. Recent advances in histopathological diagnosis, including CK8/18 staining, allow to plan the most appropriate range of multimodal treatments.

Primary small cell carcinoma of the larynx. Survival time of 47 months. Case report

Small cell carcinoma (SCC) of the larynx is a rare type of neuroendocrine carcinoma (NEC), few cases of which have been described in the literature. The prognosis for this type of carcinoma is poor, with a survival time typically not exceeding two years. We describe the case of a 54-year-old male patient with a primary tumor in the right ventricular band and a biopsy compatible with SCC. The patient underwent radiotherapy (RT) and concomitant chemotherapy (QT) and, after a relapse at 17 months, underwent total laryngectomy with bilateral neck dissection. The survival time was 47 months. Further studies are required to elucidate the possible causes of the better prognosis in some cases.

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The incidence of SCC of the larynx has increased in recent decades, although it still remains rare.

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The survival rates are 16% for two years and 5% for five years.

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We describe the case of a 54-year-old male who is still alive, a survival time of more than 44 months.

Role of ancillary techniques in profiling unclassified laryngeal malignancies

Laryngeal biopsies, contrary to biopsies from many other sites of the body, very often contain minute amounts of tumour tissue that may consist of morphologically undifferentiated tumour only. In haematoxylin- and eosin-stained sections, there may be no indicative features of what specific tumour entity that is present. In the larynx, particularly small round cell neoplasms, primary or metastatic, often cause a diagnostic dilemma and where an incorrect diagnosis can induce substantial clinical consequences for the patient (e.g., primary neuroendocrine carcinomas vs metastatic variants, certain sarcomas). If sufficient/representative material has been obtained, the application of immunohistochemistry and/or molecular techniques should in virtually every case reveal the true nature of the malignancy. In cases with sparse amount of material, and therefore a limited number of sections to be cut, a careful and thoughtful stepwise approach is necessary to ascertain a reliable diagnosis, or at least guide the clinician to the most likely diagnoses. With today's advanced and widely available technology with an abundance of markers to discriminate different tumours, the use of the term "undifferentiated" should be largely unnecessary. In the exceptional, and indeed exceedingly rare cases, when a classification is not possible, even after repeat biopsy, we suggest that the laryngeal neoplasm is better termed "unclassified malignant neoplasm" rather than "undifferentiated malignant neoplasm".

Large cell neuroendocrine carcinoma of the maxillary sinus on fine needle aspiration cytology: Report of a rare case with a focus on pitfalls in diagnosis

Head and neck large cell neuroendocrine carcinoma (LCNEC) is a rare high-grade malignant tumor with neuroendocrine differentiation. We report a case of LCNEC causing difficulty in cytological diagnosis. A 60-year-old man with right-sided face pain presented with a swelling at the right cheek, and he complained of right nasal obstruction and lacrimation. Preoperative fine-needle aspiration cytology (FNAC) showed high cellularity, with a moderate number of clusters of tumor cells on an abundant necrotic background. The clusters were arranged in sheet structures with palisading, and were cohesive with overlapping. The tumor cells had comparatively abundant cytoplasm, with conspicuous large, irregular nucleoli with a fine granular chromatin pattern. Mitotic figures were observed easily. On immunocytochemistry using LBC smear, tumor cells were negative for p40. High-grade carcinoma other than non-keratinizing squamous cell carcinoma was suggested from these findings on FNAC. The pretreatment histological biopsy sample revealed tumor cells with solid growth pattern, necrotic materials and large polygonal cells with abundant cytoplasm, fine granular chromatin, and conspicuous nucleoli. Head and neck LCNEC with abundant cytoplasm, fine granular chromatin patterns, prominent nucleoli, and necrotic background were very characteristic of LCNEC. If considered carefully, these findings can enable us to exclude the majority of non-keratinizing squamous cell carcinomas, and FNAC using ancillary technique can be very useful for proper diagnosis.

Differential Diagnosis in Neuroendocrine Neoplasms of the Larynx

The differential diagnosis of neuroendocrine neoplasms of the larynx is broad and includes lesions of epithelial, mesenchymal, and neuroectodermal origin. These lesions have overlapping clinical and pathologic aspects and must be carefully considered in the differential diagnosis of laryngeal neoplasms. The prognosis and treatment are also different among these tumor types, which necessitates making these distinctions clinically. The current literature was reviewed to provide updated information regarding the epithelial-derived tumors, including carcinoid, atypical carcinoid, small cell neuroendocrine carcinomas, large cell neuroendocrine carcinoma, and squamous cell carcinoma with neuroendocrine component. These tumors are compared and contrasted with non-epithelial-derived tumors such as paraganglioma and nonmucosal tumors, such as medullary thyroid carcinoma. The morphologic and cytologic features are discussed, along with helpful immunohistochemical and ancillary investigations.

Small cell neuroendocrine carcinoma of the nasopharynx: a rare case report

Small cell neuroendocrine carcinoma rarely appears primarily in the head and neck and exhibits aggressive behavior with a poor prognosis. The pathologist has a significant role in the diagnosis, and a consensual treatment still does not exist. The authors report the case of a middle-aged male patient who presented repeated episodes of massive epistaxis. The diagnostic work-up disclosed the diagnosis of small cell neuroendocrine carcinoma of the nasopharynx. The patient was treated with chemotherapy followed by radiotherapy. Imaging examinations performed after the end of treatment showed apparent complete remission of the disease. The patient was kept under active surveillance with no signs of local relapse or distant metastasis after 4 years of follow-up.

Sinonasal Carcinomas with Neuroendocrine Features: Histopathological Differentiation and Treatment Outcomes

Objectives Sinonasal cancers with neuroendocrine features share similar clinical, radiological, and histopathological features; however, these tumors often exhibit varying degrees of aggressive behavior presenting significant treatment challenges. The objective of this study was to report our experience with these rare malignancies and to present a review of current literature. Methods Following institutional review board approval, the records of all patients with biopsy-proven sinonasal malignancies over a 5-year period were reviewed. Results The study included 14 patients with olfactory neuroblastomas (ONBs), 7 patients with sinonasal undifferentiated carcinomas (SNUC), and 2 patients with sinonasal neuroendocrine carcinomas (SNEC). Histopathologic markers aided in final diagnosis, but showed variable specificity. In patients with sufficient follow-up, the 2-year disease-free survival rate was 81% (9/11) for ONB and 75% (3/4) for SNUC. Three patients developed a regional or distant recurrence (two with ONBs and one with SNUC). Two patients, one with SNEC and one with ONB, succumbed to brain radionecrosis related to proton radiation therapy. Conclusions Overlapping clinical and histopathological features in poorly differentiated sinonasal cancers with neuroendocrine features continue to present a diagnostic challenge. Individualized assessment and treatment strategies can improve the accuracy of the initial assessment and the treatment outcomes.

A Rare Primary Neuroendocrine Tumor (Typical Carcinoid) of the Sublingual Gland

A typical carcinoid is extremely rare in the oral cavity. We here present a case of a typical carcinoid arising in the sublingual gland of a 62-year-old woman. The tumor was removed by primary excision with 10 mm surgical margins and submandibular dissection. Examination of the tumor showed medium-sized tumor cells that were positive for CD56 and chromogranin A, with no necrosis, and with a mitotic count less than 1/10 HPF. A pathological diagnosis of typical carcinoid was made from both morphological and immunological examinations. One year after excision surgery, there was no tumor recurrence or neck metastasis.

Large Cell Neuroendocrine Carcinoma of the Head and Neck: A Clinicopathologic Series of 10 Cases With an Emphasis on HPV Status

Large cell neuroendocrine carcinoma (LCNEC) is a high-grade neuroendocrine neoplasm first described in the lung and subsequently well documented in many other anatomic sites. It has only recently been recognized that LCNEC can also occasionally arise in the head and neck. The role of human papillomavirus (HPV), which is associated with some small cell carcinomas of the head and neck, has not been investigated for LCNEC. We sought to further characterize the histologic, immunophenotypic, and clinical features of LCNEC and also investigate the role of HPV in this newly described group of tumors. The surgical pathology archives of 2 large academic institutions were searched for cases of LCNEC arising in the head and neck. p16 immunohistochemistry and HPV in situ hybridization were performed, and clinical information was obtained from electronic medical records. Ten cases of head and neck LCNEC were identified. The tumors arose in 6 men and 4 women ranging in age from 14 to 70 years (median, 63.5 y). The primary tumor sites were the oropharynx (n=4), the sinonasal tract (n=3), and the larynx (n=3). The LCNECs consisted of nests and trabeculae of medium-large cells with abundant cytoplasm, coarse chromatin, and prominent nucleoli with very high mitotic rates. The tumor nests were often associated with necrosis, peripheral palisading, and rosette formations. The LCNECs were positive for pan-cytokeratin and at least 1 neuroendocrine marker (most often synaptophysin) and were largely negative for p63 (focal staining in 2/10) and CK5/6 (staining in 1/10). The LCNECs demonstrated aggressive clinical behavior: 8 of 10 presented with advanced disease, 5 of 10 died, with 4 more living but with persistent tumor. Three of 10 LCNECs were HPV-related (HPV-LCNEC); they arose in the oropharynx (n=2) and sinonasal tract (n=1). The HPV-LCNECs did not differ from the HPV-negative tumors in histologic appearance or behavior: 2 patients with HPV-LCNEC have died because of their disease and 1 remains alive but with widespread metastases. LCNEC is a rare but distinct form of head and neck carcinoma that exhibits aggressive clinical behavior. A subset of oropharyngeal and sinonasal LCNEC is HPV related, but the presence of HPV may not impart a more favorable prognosis. Because of its aggressive behavior, LCNEC should be distinguished from moderately differentiated neuroendocrine carcinoma and squamous cell carcinoma. The morphology of LCNEC overlaps considerably with the nonkeratinizing appearance of HPV-related squamous cell carcinoma, and as a result a high index of suspicion is needed to identify LCNEC. Immunohistochemical studies for synaptophysin and p63 are helpful tools for making this distinction.

The Differential Diagnosis of Sinonasal/Nasopharyngeal Neuroendocrine/Neuroectodermally Derived Tumors

CONTEXT

The differential diagnosis of neuroendocrine neoplasms arising in the sinonasal tract is broad and includes lesions of epithelial, mesenchymal, and neuroectodermal origin.

OBJECTIVE

To review the differential diagnosis of sinonasal neuroendocrine and neuroectodermally derived tumors.

DATA SOURCES

The current literature was reviewed to provide updated information regarding the differential diagnosis and means for diagnosing neuroendocrine tumors including sinonasal neuroendocrine carcinoma, olfactory neuroblastoma, malignant melanoma, paraganglioma, pituitary adenoma, and Ewing family of tumors.

CONCLUSIONS

The differential diagnosis of neoplasms with neuroendocrine differentiation in the sinonasal tract is broad, and diagnosis often includes not only histologic review but also immunohistochemical or molecular analysis.

Neuroendocrine tumours in rare sites: differences in nomenclature and diagnostics-a rare and ubiquitous histotype

The diagnosis of neuroendocrine tumours in typical sites, as gastrointestinal tract and lung, is based upon well-coded criteria that have become familiar to most of the pathologists. Much more difficult is the recognition and allocation of proper nomenclature to be referred to the same histotype in locations where these tumours have a lower incidence. The aim of our review was to provide a quick handbook of the main diagnostic pitfalls known in literature that can interpose in the histopathological examination of neuroendocrine tumours in rare sites (urinary system and male genital organs, female genital organs, head and neck and breast).

Neuroendocrine Neoplasms of the Sinonasal Tract: Neuroendocrine Carcinomas and Olfactory Neuroblastoma

Neuroendocrine neoplasms (NENs) can occur in organs or tissues that do not contain neuroendocrine cells normally and do not necessarily imply embryologic derivation from the neuroectoderm; but rather reflect a shared phenotype characterized by the expression of multiple genes encoding both endocrine and neuronal features. NENs are rare in the sinonasal tract and are subdivided into epithelial and neural subtypes based on the presence of keratins or neurofilaments, respectively. Although relatively rare, neuroendocrine carcinomas (NECs) and olfactory neuroblastoma (ONB) are the most common neuroendocrine neoplasms of the sinonasal tract. The focus of this review is to highlight recent developments in the pathology of sinonasal NECs and ONB in light of the upcoming update of the World Health Organization (WHO) 2005 classification of tumors of the head and neck.

High-Grade Neuroendocrine Carcinoma of the Larynx

Objective:

To report a single institutional series of high-grade neuroendocrine carcinoma of the larynx (NCL), a very rare yet aggressive tumor. To review the management of NCL, including discussion of clinical behavior, treatment outcome, and prognosis.

Method:

A retrospective chart review of high-grade laryngeal neuroendocrine carcinomas at a single institution, including small- and large-cell neuroendocrine carcinomas. A total of 8 patients with high-grade NCL treated at our institution from 1992 to 2014 were identified.

Results:

The median age at diagnosis was 65.5 years (range, 43-80). Five patients were male. Two patients had a known smoking history. Primary tumor location was supraglottic in 7 patients and glottic in 1 patient. Primary treatment consisted of surgery alone (3 patients), radiotherapy alone (1 patient), combination of chemotherapy and radiotherapy (1 patient), and surgery followed by postoperative chemoradiotherapy (3 patients). Locoregional recurrence followed by distant metastasis occurred in 6 patients. Median overall survival was 44.0 months (95% CI, 3-62.0).

Conclusion:

High-grade NCL is a rare diagnosis. Compared to well- and moderately differentiated NCL, high-grade NCL has a far more aggressive clinical course and associated with a worse prognosis. To our knowledge, this is the largest series of patients with high-grade NCL treated at a single institution. Prompt diagnosis and multimodality therapy including elective neck dissection may improve survival.