Sinonasal undifferentiated carcinoma: immunohistochemical profile and lack of EBV association

Non-Epstein-Barr Virus Sinonasal Undifferentiated Carcinoma Presenting as Diplopia and Rhinorrhea

Sinonasal undifferentiated carcinoma (SNUC) is an extremely rare and highly aggressive malignant neoplasm of the nasal cavity and/or paranasal sinuses. SNUC is clinicopathologically distinctive from other tumors but is difficult to study due to its low incidence. There is also very little consensus about the etiology of SNUC, including its association with Epstein-Barr virus (EBV). Treatment modalities include surgery, chemotherapy, and radiation depending on the stage and grading. Herein, we discuss a patient who presented to the emergency department with chronic rhinorrhea and various ophthalmologic symptoms such as flashes, floaters, and diplopia. The patient was later diagnosed with SNUC in the setting of negative serological testing for EBV in addition to his previously concomitant history of bladder cancer. The purpose of this case report is to contribute to the broader literature of SNUC and the specifics surrounding the diagnostic modalities utilized, management, and outcome of non-EBV sinonasal undifferentiated carcinoma in a patient with atypical symptomatology.

PET/CT Imaging in Treatment Planning and Surveillance of Sinonasal Neoplasms

Sinonasal cancers are uncommon malignancies with a generally unfavorable prognosis, often presenting at an advanced stage. Their high rate of recurrence supports close imaging surveillance and the utilization of functional imaging techniques. Whole-body 18F-FDG PET/CT has very high sensitivity for the diagnosis of sinonasal malignancies and can also be used as a "metabolic biopsy" in the characterization of some of the more common subgroups of these tumors, though due to overlap in uptake, histological confirmation is still needed. For certain tumor types, radiotracers, such as 11C-choline, and radiolabeled somatostatin analogs, including 68Ga-DOTATATE/DOTATOC, have proven useful in treatment planning and surveillance. Although serial scans for posttreatment surveillance allow the detection of subclinical lesions, the optimal schedule and efficacy in terms of survival are yet to be determined. Pitfalls of 18F-FDG, such as post-surgical and post-radiotherapy crusting and inflammation, may cause false-positive hypermetabolism in the absence of relapse.

Top 10 Histological Mimics of Neuroendocrine Carcinoma You Should Not Miss in the Head and Neck

BACKGROUND

The spectrum of neuroendocrine neoplasia (NEN) of the head and neck region is wide-ranging and diverse, including a variety of diagnoses stretching from benign and low-malignant tumor forms to highly proliferative, poor prognosis neuroendocrine carcinoma (NEC). Moreover, there are several non-neuroendocrine differential diagnoses to keep in mind as well, displaying various degree of morphological and/or immunohistochemical overlap with bona fide neuroendocrine lesions.

METHODS

Review.

RESULTS

While the growth patterns may vary, well-differentiated NEN usually display a stippled "salt and pepper" chromatin, a granular cytoplasm, and unequivocal expression of neuroendocrine markers such as chromogranin A and synaptophysin. However, these features are often less pronounced in NEC, which may cause diagnostic confusion-not the least since several non-NEC head and neck tumors may exhibit morphological similarities and focal neuroendocrine differentiation.

CONCLUSION

As patients with NEC may require specific adjuvant treatment and follow-up, knowledge regarding differential diagnoses and potential pitfalls is therefore clinically relevant. In this review, the top ten morphological and/or immunohistochemical mimics of NEC are detailed in terms of histology, immunohistochemistry, and molecular genetics.

IDH2 -Mutated Sinonasal Tumors: A Review

INTRODUCTION

Genetic profiling has caused an explosion in the subclassification of sinonasal malignancies. Distinguishing several of these tumor types by histomorphology alone has been quite challenging, and although pathologic classification aims to be as specific as possible, it remains to be seen if this recent move toward tumor speciation bears clinical relevance, most particularly focused on subtyping for the sake of prognostication and treatment. One such recently described cohort, predominantly lumped under the moniker of sinonasal undifferentiated carcinoma (SNUC) is IDH2 -mutated sinonasal carcinoma, a high-grade carcinoma associated with mutations in the isocitrate dehydrogenase-2 ( IDH2 ) gene. A hotspot mutation in the R172 codon has been described in 50% to 80% of the tumors classified as SNUC, large cell neuroendocrine carcinomas, and rarely in cases classified as olfactory neuroblastoma. The use of immunohistochemical and molecular approaches is required to correctly identify this subset of sinonasal tumors, with further study necessary to elucidate their unique pathophysiology, ultimately determining whether a revision is required toward the current therapeutic approach.

AIMS

Here, we provide an overview of the IDH2- mutated sinonasal tumors, discuss histopathologic and clinical features, and focus on molecular diagnostics and novel immunohistochemical markers.

RESULTS

A review of the literature reveals 82 reported cases with IDH2 -mutated sinonasal tumors (IST), confirmed either by molecular studies or diagnostic immunohistochemical markers. The mean patient age is 60 years (female/male: 1/1.4), the median tumor size is 5 cm (range: 2.5 to 7.0 cm), and the most common location is the nasal cavity (81%). IST displays tumor necrosis and increased mitotes. Histopathologically, IST shows SNUC-like, large cell neuroendocrine carcinomas-like, or poorly differentiated carcinoma-like features (77%, 12%, and 9%, respectively). The molecular hotspot alterations in mitochondrial IDH2 are: R172S (61%), R172T (19%), R172G (7%), and R172M (3%). Sixty-five percent of tumors are surgically resectable, and all patients received chemotherapy, radiation therapy, or both. Rates of locoregional recurrence and distant metastasis are 60% and 40%, respectively. One-, 3- and 5-year survival rates are 83%, 50%, and 43%, respectively. In all but 1 study, IST is associated with better outcomes than IDH2 wild-type tumors and SMARCB1 -deficient sinonasal tumors.

Top 10 Basaloid Neoplasms of the Sinonasal Tract

BACKGROUND

Basaloid neoplasms of the sinonasal tract represent a significant group of tumors with histological overlap but often with different etiologies (i.e., viral, genetics), clinical management, and prognostic significance.

METHODS

Review.

RESULTS

"Basaloid" generally refers to cells with coarse chromatin in round nuclei and sparse cytoplasm, resembling cells of epithelial basal layers or imparting an "immature" appearance. Tumors with this characteristic in the sinonasal tract are represented by a spectrum of benign to high-grade malignant neoplasms, such as adenoid cystic carcinoma, NUT carcinoma, sinonasal undifferentiated carcinoma, SWI/SNF complex-deficient carcinomas, and adamantinoma-like Ewing sarcoma.

CONCLUSION

In some instances, histology alone may be sufficient for diagnosis. However, limited biopsy material or fine-needle aspiration specimens may be particularly challenging. Therefore, often other diagnostic procedures, including a combination of histology, immunohistochemistry (IHC), DNA and RNA testing, and molecular genetics are necessary to establish an accurate diagnosis.

The contemporary management of cancers of the sinonasal tract in adults

Sinonasal malignancies make up <5% of all head and neck neoplasms, with an incidence of 0.5-1.0 per 100,000. The outcome of these rare malignancies has been poor, whereas significant progress has been made in the management of other cancers. The objective of the current review was to describe the incidence, causes, presentation, diagnosis, treatment, and recent developments of malignancies of the sinonasal tract. The diagnoses covered in this review included sinonasal undifferentiated carcinoma, sinonasal adenocarcinoma, sinonasal squamous cell carcinoma, and esthesioneuroblastoma, which are exclusive to the sinonasal tract. In addition, the authors covered malignances that are likely to be encountered in the sinonasal tract-primary mucosal melanoma, NUT (nuclear protein of the testis) carcinoma, and extranodal natural killer cell/T-cell lymphoma. For the purpose of keeping this review as concise and focused as possible, sarcomas and malignancies that can be classified as salivary gland neoplasms were excluded.

Rare Diseases of the Nose, the Paranasal Sinuses, and the Anterior Skull Base

Due to their low incidence and thus resulting limited diagnostic criteria as well as therapeutic options, rare diseases of the nose, the paranasal sinuses, and the anterior skull base are a significant challenge. The value as of which a disease has to be considered as rare amounts to a maximum of 5 patients per 10 000 people. Within these diseases, however, there are extreme differences. Some rare or orphan diseases like for example the inverted papilloma belong to regularly diagnosed and treated diseases of larger departments of oto-rhino-laryngology whereas other rare diseases and malformations have only been described in less than 100 case reports worldwide. This fact emphasizes the necessity of bundling the available experience of diagnostics and therapy. The present article gives an overview about rare diseases of the nose, the paranasal sinuses, and the anterior skull base from the field of diseases/syndromes of the olfactory system, malformations of the nose and paranasal sinuses, ventilation and functional disorders as well as benign and malignant tumors. The classification and data on diagnostic and therapeutic options were established based on the current literature.

Risk of Rare Cancers Among Solid Organ Transplant Recipients

BACKGROUND

Immunosuppressed solid organ transplant recipients (SOTRs) have elevated rates of certain rare cancers caused by viruses. Evaluating risk of rare cancers among SOTRs may provide etiological clues for additional cancers linked to poor immunity and viral infections.

METHODS

We performed a cohort study of 262 455 SOTRs (1987-2014) from the US SOTR registry linked to 17 population-based cancer registries. First cancers in SOTRs were categorized using an established classification scheme based on site and histology. Standardized incidence ratios (SIRs) compared risk in SOTRs with the general population. We used Poisson regression to calculate incidence rate ratios according to immune-related SOTR characteristics, including time since transplant (ie, duration of immunosuppression). All statistical tests were 2-sided.

RESULTS

We examined 694 distinct cancer subtypes, with 33 manifesting statistically significantly elevated SIRs (Bonferroni P < 7.2 × 10-5). All 33 are rare (incidence <6 per 100 000 person-years) and several have known viral etiology (eg, Merkel cell carcinoma: SIR = 24.7, 95% confidence interval [CI] = 20.8 to 29.1). Additional cancers that were increased include squamous cell carcinomas of the lip (SIR range = 18.3-19.8), eye and adnexa (SIR = 13.8, 95% CI = 7.9 to 22.3), salivary gland (SIR = 9.3, 95% CI = 6.1 to 13.5), and nasal cavity and sinuses (SIR = 4.5, 95% CI = 2.8 to 6.8); sebaceous adenocarcinoma (SIR = 34.3, 95% CI = 26.3 to 44.0); malignant fibrous histiocytoma (15.4); and subtypes of bladder, kidney, lung, and colon cancer (SIR range = 3.2-13.3). Incidence of several cancers increased over time since transplant (Ptrend < .05), including squamous cell carcinomas of the lip, salivary gland, and anogenital sites.

CONCLUSIONS

SOTRs experience elevated rates of several rare cancers. Because some of these cancers exhibit aggressive behavior with poor outcomes, it is important to further characterize the role of immunity and the potential involvement of oncogenic viruses to improve prevention and treatment.

Clinical management of localized undifferentiated sinonasal carcinoma: our experience and review of the literature

Undifferentiated sinonasal carcinoma (SNUC) is defined as a small round blue cell tumor that is immunohistochemically distinct from other sinonasal malignancies, such as lymphoma, mucosal melanoma, nasopharyngeal carcinoma, neuroendocrine carcinoma, and olfactory neuroblastoma. SNUCs are very aggressive malignancies, provoking quick destruction of the splanchnocranium structures. Being a very rare neoplasm, there are no prospective clinical trials assessing their treatment strategies, so lots of data are derived by small retrospective trials. Tri-modality treatments (namely those treatments which use together surgery, radiation therapy and chemotherapy) are now considered the best of care for this category of poor prognosis tumors, and whenever possible they should be employed. Despite the tri-modality treatments and the multidisciplinary management, SNUCs are characterized by poor prognosis with a median overall survival reaching 14 months. Ameliorating radiotherapy techniques and performing therapies adapted to the genetics of the disease could represent a promising strategy of therapy in the near future. In this report, we have presented our experience, describing the treatment and the prognosis of four patients seen at our Institution. Moreover, we have performed a review of the literature analyzing the now available therapy options and the possible future strategies.

Sinonasal Undifferentiated Carcinoma (SNUC): From an Entity to Morphologic Pattern and Back Again-A Historical Perspective

Since the first description of sinonasal undifferentiated carcinoma (SNUC) as a distinctive highly aggressive sinonasal neoplasm with probable origin from the sinonasal mucosa (Schneiderian epithelium), SNUC has been the subject of ongoing study and controversy. In particular, the SNUC category gradually became a "wastebasket" for any undifferentiated or unclassifiable sinonasal malignancy of definite or probable epithelial origin. However, with the availability of more specific and sensitive immunohistochemical antibodies and increasing implementation of novel genetic tools, the historical SNUC category became the subject of progressive subdivision leading to recognition of specific genetically defined, reproducible subtypes. These recently recognized entities are characterized by distinctive genetic aberrations including NUTM1-rearranged carcinoma (NUT carcinoma) and carcinomas associated with inactivation of different members of the SWI/SNF chromatin-remodeling gene complex such as SMARCB1-deficient and less frequently SMARCA4-deficient carcinoma. The ring became almost closed, with recent studies highlighting frequent oncogenic IDH2 mutations in the vast majority of histologically defined SNUCs, with a frequency of 82%. A review of these cases suggests the possibility that "true SNUC" probably represents a distinctive neoplastic disease entity, morphologically, phenotypically, and genetically. This review addresses this topic from a historical perspective, with a focus on recently recognized genetically defined subsets within the SNUC spectrum.

Loss of SMARCB1 Expression Confers Poor Prognosis to Sinonasal Undifferentiated Carcinoma

Background  Due to the diverse histopathologic features and variable survival rates seen in sinonasal undifferentiated carcinoma (SNUC), it is likely that this diagnostic entity is comprised of a heterogonous group of morphologically undifferentiated tumors. As advancements in molecular testing have led to a better understanding of tumor biology, it has become increasingly evident that SNUC may actually encompass several tumor subtypes with different clinical behavior. As a result, it is also likely that all SNUC patients cannot be treated in the same fashion. Recent investigations have identified loss of the tumor suppressor SMARCB1 (INI1) expression in a subset of undifferentiated sinonasal tumors and extrasinonasal tumors and, studies have suggested that this genetic aberration may be a poor prognostic marker. The objective of this study was to identify differential expression of SMARCB1 in SNUC and to analyze and compare the survival outcomes in SNUC patients with and without SMARCB1 expression. Methods  All cases of undifferentiated or poorly differentiated neoplasms of the sinonasal tract treated between 2007 and 2018 at a single tertiary care institution were selected. All cases of SNUC were tested for SMARCB1 status by immunohistochemistry (IHC). Clinical parameters were analyzed using Student's t -test and Fischer's test. Kaplan-Meier methods were used to estimate survival durations, while comparison between both the subgroups was done using the log-rank test. Statistical analysis was performed with the use of SPSS software, Version 25 (IBM, New York, NY, United States). Results  Fourteen cases of SNUC were identified. Approximately two-thirds (64%; n  = 9) of patients were male and the majority (79%; n  = 11) were between fifth to seventh decade. Skull base and orbital invasion were seen in 79% ( n  = 11) and 93% ( n  = 13) of cases, respectively. Fifty-seven percent of tumors ( n  = 8) retained SMARCB1 expression by IHC (SR-SNUC), while the remaining 43% ( n  = 6) showed loss of SMARCB1 expression and, thus, were considered as SMARCB1 -deficient (SD-SNUC). Although clinicopathological features and treatment modalities were similar, SD-SNUC showed poorer (OS: p  = 0.07; disease free survival [DFS]: p  = 0.02) overall survival (OS) and DFS on Kaplan-Meier curves. Additionally, SD-SNUC showed higher recurrence (75 vs. 17%) and mortality (67 vs. 14%) (hazard rate = 8.562; p  = 0.05) rates. Both OS (28.82 ± 31.15 vs. 53.24 ± 37.50) and DFS durations (10.62 ± 10.26 vs. 43.79 ± 40.97) were consistently worse for SD-SNUC. Five-year survival probabilities were lower for SD-SNUC (0.33 vs. 0.85). Conclusion  SNUC represents a heterogeneous group of undifferentiated sinonasal malignancies. Based on the status of SMARCB1 expression, the two subgroups SD-SNUC and SR-SNUC appear to represent distinct clinical entities, with loss of SMARCB1 expression conferring an overall worse prognosis.

Sinonasal Undifferentiated Carcinoma

PURPOSE OF REVIEW

To provide a comprehensive review of the literature highlighting the recent advances in the diagnosis and management of sinonasal undifferentiated carcinoma (SNUC) RECENT FINDINGS: SNUC usually presents at advanced stage and the prognosis is usually poor with high rates of locoregional recurrence and tendency to metastasize. Special attention should be made in differentiating SNUC from other sinonasal malignancies in order to guide the appropriate treatment accordingly. Multimodality treatment is usually recommended for treating SNUC. The use of neoadjuvant chemotherapy may be associated with improved outcome and can be used to guide the subsequent treatment selection. Despite the recent advances in chemotherapeutic agents, radiation techniques, and surgical approaches, the prognosis and survival outcomes of SNUC remain poor. The addition of induction chemotherapy to the treatment approach followed by definitive local therapy needs to be further studied as it might improve the outcome.

The Role of SATB2 as a Diagnostic Marker of Sinonasal Intestinal-type Adenocarcinoma

BACKGROUND

Intestinal-type adenocarcinoma (ITAC) of the nasal cavity and paranasal sinuses is an uncommon tumor associated with exposure to wood and leather dust, nickel, and possibly smoking. ITAC shares phenotypical features with colorectal carcinoma. In contrast to most non-intestinal-type sinonasal adenocarcinomas, ITAC is an aggressive adenocarcinoma with poor clinical outcome; therefore, its reliable separation from non-ITAC is very important.

AIM

The use of a combination of immunohistochemical markers of intestinal differentiation was tested in a cohort of sinonasal carcinomas of different types. The aim of this study was to explore a new intestinal marker, SATB2, in conjunction with CDX2 and CK20 in differential diagnosis of sinonasal adenocarcinomas.

MATERIALS AND METHODS

Seven ITACs, 66 non-ITACs, and 1 case of extensive intestinal metaplasia (IM) of the nasal mucosa were included in the study and stained with SATB2, CK20, CDX2, and CK7 antibodies. Detection of mismatch repair proteins was performed in all cases of ITAC. All 7 sinonasal ITACs have been tested for KRAS, NRAS, and BRAF gene mutations.

RESULTS

All ITACs showed positive expression for SATB2, whereas all non-ITAC cases were negative. The only 1 case of IM was found to be positive for SATB2, whereas the same case showed negative expression of CK20 and only focal immunostaining for CDX2. The genetic analysis showed that only 1 sinonasal ITAC (1/7) showed KRAS c.35G>C, p.(Gly12Ala) mutation, whereas BRAF and NRAS genes were wild type. Four ITACs revealed wild-type KRAS, NRAS, and BRAF, and 2 remaining cases were not analyzable. All ITACs showed preserved nuclear expression of mismatch repair proteins.

CONCLUSIONS

SATB2 in combination with CDX2 and CK20 differentiates sinonasal ITAC from non-ITAC with increased diagnostic sensitivity and specificity and detects IM in the sinonasal tract more easily.

Genetic profiling of poorly differentiated sinonasal tumours

The sinonasal cavities harbour a variety of rare tumour types. Many carry a poor prognosis while therapeutic options are limited. Histopathological classification can be difficult, especially for poorly differentiated tumours such as olfactory neuroblastoma (ONB), sinonasal neuroendocrine carcinoma (SNEC) and sinonasal undifferentiated carcinoma (SNUC). We analysed Affymetrix OncoScan genome-wide copy number profiles of these three tumour types, both as originally diagnosed and as regrouped by their cytokeratin (Ck) and neuroendocrine (Ne) expression pattern, aiming to find a relation between phenotype and genotype. According to the original histopathological classification our series consisted of 24 ONB, 11 SNEC and 19 SNUC, while immunohistochemistry indicated 11 Ck−Ne+/ONB, 18 Ck+Ne+/SNEC, 24 Ck+Ne−/SNUC, and 1 Ck−Ne−/unclassified. As originally diagnosed, the three tumour types showed similar copy number profiles. However, when regrouped by Ck/Ne immunostaining we found a distinct set of gains and losses; Ck−Ne+/ONB harboured few and predominantly whole chromosomes abnormalities, Ck+Ne+/SNEC carried both gains and losses in high frequency, and Ck+Ne−/SNUC showed mostly gains. In addition, each tumour carried a number of unique chromosomal deletions. Genome-wide copy number profiling supports the value of immunohistochemical CkNe staining of ONB, SNEC and SNUC for tumour classification, which is important for prognosis and therapeutic decision-making.

Deregulation of selected microRNAs in sinonasal carcinoma: Value of miR-21 as prognostic biomarker in sinonasal squamous cell carcinoma

BACKGROUND

Tumors occurring in the sinonasal area are characterized by unfavorable outcome due to difficult diagnosis, treatment, and prognosis of the disease corresponding with the anatomic complexity of the area.

METHODS

We used quantitative real-time polymerase chain reaction (PCR) to compare relative expression of miR-21, miR-141, and miR-200c in 70 formalin-fixed, paraffin-embedded samples of sinonasal carcinoma tissue (majority of squamous cell carcinoma [SCC] samples) with 17 control samples of sinonasal tissue.

RESULTS

Our data showed significant upregulation of miR-21 in sinonasal cancer tissue. Expression levels of miR-141 and miR-200c were below detectable levels in both sinonasal cancer samples and healthy tissue. Kaplan-Meier analysis with log-rank survival showed that patients with SCC with high expression of miR-21 (highest quartile) had impaired survival close to reaching statistical significance (P = .0630).

CONCLUSION

Our results suggest that miR-21 upregulation is involved in tumorigenesis of sinonasal carcinoma and that it is associated with poor prognosis. Thus, miR-21 could be used as a valuable prognostic biomarker.

The presence of neuroendocrine features generates a broad differential diagnosis in the fine-needle aspiration of bone and soft tissue neoplasms

INTRODUCTION

Biopsy of bone and soft tissue (BST) lesions occasionally yields neoplasms with neuroendocrine (NE) features. We identify a differential diagnosis for neoplasms containing NE features when encountered on fine-needle aspiration (FNA) of BST masses.

MATERIALS AND METHODS

The cytopathology archives of the Johns Hopkins Hospital were searched for any BST FNA specimen diagnosed as a neoplasm with NE features or in which NE immunohistochemical (IHC) markers were ordered. Specimen diagnoses were reviewed and specimens were excluded if neuroendocrine features were not considered at the time of original diagnosis.

RESULTS

A total of 179 specimens met the inclusion criteria. Of these, 64 (36%) and 115 (64%) neoplasms were primary and metastatic, respectively. A total of 29 distinct entities were identified. Sixteen were entities with established NE differentiation and 13 were entities not typically regarded as having an NE origin. The most commonly encountered neoplasms included small cell carcinoma of all primary locations (38), Ewing sarcoma (37), medullary thyroid carcinoma (24), Merkel cell carcinoma (23), and paraganglioma (10). NE IHC markers were ordered in 45% of cases; 86% were positive by at least one NE marker. Entities with established NE differentiation were more likely to be positive for NE IHC than those not typically regarded as having NE differentiation (100% and 59%, respectively).

CONCLUSIONS

A variety of BST lesions-including neoplasms not typically thought to have neuroendocrine differentiation-can possess NE cytomorphologic features and/or NE IHC marker positivity. The patient's clinical presentation and history can help narrow the differential diagnosis.

Recurrent IDH2 R172X mutations in sinonasal undifferentiated carcinoma

Sinonasal undifferentiated carcinoma is a rare and aggressive malignancy. Sinonasal undifferentiated carcinoma has long been considered a diagnosis of exclusion; to date, the molecular pathogenetic basis for sinonasal undifferentiated carcinoma is unknown. To identify potential oncogenic drivers in sinonasal undifferentiated carcinoma, targeted next-generation sequencing of 300 cancer-related genes was performed on 11 cases of sinonasal undifferentiated carcinoma. We identified IDH2 R172X mutations in 55% of sinonasal undifferentiated carcinomas including R172S, R172T, and R172M. Multispecific mutant IDH1/2 immunohistochemistry was performed and identified mutant-specific protein expression in all cases with available tissue: 3/3 sinonasal undifferentiated carcinomas with R172 mutations were positive and 4/4 wild-type cases were negative. Review of sequencing data for our institutional head and neck cohorts (n=412) confirmed the absence of IDH-activating mutations in other tumor types. Alterations in the IDH2-wild-type sinonasal undifferentiated carcinomas included SMARCA4 loss-of-function with confirmed loss of immunohistochemical expression, NOTCH1 gain-of-function, and TET2 loss-of-function. We demonstrate that the majority of histologically defined sinonasal undifferentiated carcinomas are characterized by IDH2 R172X mutations and overexpression of mutant protein. IDH2 R172X mutations are specific to sinonasal undifferentiated carcinoma among carcinomas of the head and neck, confirming this tumor type as a distinct clinicopathologic entity. These findings have significant implications for diagnosis and therapy with IDH inhibitors for patients with this rare and poorly understood tumor.

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.

Sinonasal Small Round Blue Cell Tumors: An Immunohistochemical Approach

Although clinical history and morphologic appearance should be the initial considerations when evaluating small round blue cell tumors of the sinonasal tract, the final diagnosis often hinges on immunohistochemical findings. Unfortunately, interpretation of stains in these tumors is fraught with numerous pitfalls and limitations. This article presents an approach to sinonasal small round blue cell tumors based on four common immunohistochemical patterns: cytokeratin positivity, squamous marker positivity, neuroendocrine marker positivity, and cytokeratin negativity.

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.

Meta-analysis of 701 published cases of sinonasal neuroendocrine carcinoma: The importance of differentiation grade in determining treatment strategy

The aim of this meta-analysis was to provide treatment guidelines for sinonasal neuroendocrine carcinoma (SNC) by combining all available data in the literature. A literature search for all studies concerning SNC was performed against the MEDLINE and EMBASE databases. Available clinical data was normalized, pooled, and statistically analyzed. A total of 701 cases of SNC were available for analysis, comprising 127 well or moderately differentiated sinonasal neuroendocrine carcinomas (SNEC), 459 sinonasal undifferentiated carcinoma (SNUC) and 115 sinonasal small cell carcinoma (SmCC). Tumor type was the most important predictor of survival, with a 5-year disease-specific survival (DSS) of 70.2% for SNEC, 35.9% for SNUC and 46.1% for SmCC. Tumor stage on presentation was of limited value in predicting survival or response to treatment. Overall, the application of surgery yielded significantly better results (5-year DSS 52.2% versus 30.1%, p<0.001). In SNUC, radiotherapy was a beneficial supplement to surgery (5-year DSS 54.7% versus 15.7%, p=0.027), while radiotherapy as monotherapy performed poorly (5-year DSS 17.9%). Chemotherapy did not appear to contribute to survival. Based on these findings, we can conclude that the most important predictors of survival in SNC are differentiation grade and the associated choice of treatment modality. In contrast to other head and neck cancers, tumor staging appears of limited value in predicting survival or deciding on a treatment strategy. Surgery should be the cornerstone of treatment, supplemented by radiotherapy in poorly differentiated subtypes (SNUC, SmCC). Chemotherapy does not appear to contribute to survival.

Role of 18 F-FDG PET/CT differentiating olfactory neuroblastoma from sinonasal undifferentiated carcinoma

OBJECTIVES

The purpose of this study is to demonstrate the potential contribution of positron emission tomography (PET)/computed tomography (CT) to help differentiate olfactory neuroblastoma (ONB) from sinonasal undifferentiated carcinoma (SNUC).

METHODS

Following approval by the institutional review board at the Wexner Medical Center at the Ohio State University, Columbus, Ohio, a pilot study with retrospective review of patients with biopsy-proven diagnosis of ONB s and SNUC s was conducted. Staging PET/CT scans were reviewed to document the maximum standardized uptake value (SUVmax). A statistical comparison of SUVmax was performed.

RESULTS

We identified 13 patients (7 with ONBs and 6 with SNUCs) with mean age 60.2 years who had undergone staging F-18 fluorodeoxyglucose (¹⁸ F-FDG) PET/CT of the primary tumor at the time of their diagnosis. Mean SUVmax was found to be five-fold higher in SNUC patients (35.63, range 10.8-77.9) than in ONB patients (7.24, range 4.6-10.7) (P ≤ 0.00169).

CONCLUSION

Maximum standardized uptake value of ¹⁸ F-FDG PET/CT can be used to initially discriminate between ONB and SNUC. This finding may prove helpful to guide diagnostic and treatment planning when the histopathologic diagnosis is inconclusive.

LEVEL OF EVIDENCE

4. Laryngoscope, 2016 127:321-324, 2017.

Oral environment and cancer

Cancer is now the leading cause of death in Japan. A rapid increase in cancer mortality is expected as Japan is facing a super-aged society. Many causes of cancer are known to be closely linked to life style factors, such as smoking, drinking, and diet. The oral environment is known to be involved in the pathogenesis and development of various diseases such as bronchitis, pneumonia, diabetes, heart disease, and dementia. Because the oral cavity acts as the bodily entrance for air and food, it is constantly exposed to foreign substances, including bacteria and viruses. A large number of bacteria are endemic to the oral cavity, and indigenous oral flora act to prevent the settlement of foreign bacteria. The oral environment is influenced by local factors, including dental plaque, tartar, teeth alignment, occlusion, an incompatible prosthesis, and bad lifestyle habits, and systemic factors, including smoking, consumption of alcohol, irregular lifestyle and eating habits, obesity, stress, hormones, and heredity. It has recently been revealed that the oral environment is associated with cancer. In particular, commensal bacteria in the oral cavity are involved in the development of cancer. Moreover, Candida, human papilloma virus and Epstein-Barr virus as well as commensal bacteria have been reported to be associated with the pathogenesis of cancer. In this review, we introduce recent findings of the correlation between the oral environment and cancer.

An Update on Sinonasal Round Cell Undifferentiated Tumors

The sinonasal cavities host a wide variety of undifferentiated malignancies with round cell morphology, including neoplasms of epithelial, mesenchymal, neuroectodermal, and hematolymphoid lineage. The differential diagnosis may be difficult, especially in small biopsy material, due to overlapping morphology, but their correct classification is clinically relevant. The aim of this review is to provide practical guidelines for the differential diagnosis of these malignancies, with emphasis on recently described entities and special reference to the role of ancillary techniques.

Human epidermal growth factor receptor 2/neu as a novel therapeutic target in sinonasal undifferentiated carcinoma

BACKGROUND

Sinonasal undifferentiated carcinoma (SNUC) is a rare and aggressive cancer. Despite multimodal therapy, the prognosis in SNUC remains poor, and new therapies are needed. Thus, the purpose of this study was to explore potential therapeutic targets in SNUC.

METHODS

Using the human-derived SNUC MDA8788-6 cell line, we performed whole genome single nucleotide polymorphism (SNP) analysis to identify copy number changes in this line. Protein expression levels were evaluated by Western blotting. Cell growth inhibition was assessed by methylthiazol tetrazolium (MTT) and clonogenic assays. The mouse flank model was used to examine the effect of growth inhibition in vivo.

RESULTS

The ERBB2 gene was highly amplified and cell extracts showed human epidermal growth factor receptor 2 (HER2) was overexpressed and phosphorylated in MDA8788-6. Lapatinib effectively inhibited the HER2 signaling pathway in our SNUC cell line. HER2 inhibition successfully suppressed the cell growth of MDA8788-6 cells both in vitro and in vivo.

CONCLUSION

Targeting HER2 may be a promising avenue for the development of novel therapies for SNUC. © 2016 Wiley Periodicals, Inc. Head Neck 38: E1926-E1934, 2016.

Nodal metastasis and elective nodal level treatment in sinonasal small-cell and sinonasal undifferentiated carcinoma: a surveillance, epidemiology and end results analysis

OBJECTIVE

Risk of nodal involvement in patients with sinonasal small-cell carcinoma and sinonasal undifferentiated carcinoma (SNUC) has not been well defined because of their rarity. We describe a population-based assessment of specific nodal level involvement in this group of rare neuroectodermal tumours.

METHODS

The Surveillance, Epidemiology and End Results (SEER) database from 2004 to 2011 identified patients with SNUC and sinonasal small-cell carcinoma. Overall neck involvement and individual nodal level involvement at presentation were assessed, and comparison was made with a contemporaneous cohort of patients with a borderline clinically significant risk of nodal involvement and recurrence.

RESULTS

Of 141 patients, 31 (22%) had gross nodal involvement at presentation (range 14-33% by site and histology). Non-nasal, non-ethmoid site with SNUC histology has the highest rates of initial nodal involvement, whereas higher stage and size do not predict for higher nodal involvement rates. Bilateral Levels 2-3 for all sinonasal small cell; Levels 2-3 for nasal or ethmoid SNUC; and bilateral Levels 1-3 in non-nasal/non-ethmoid SNUC have the highest rates of involvement compared with a clinical reference standard.

CONCLUSION

We found high rates of initial nodal involvement in all SNUC and sinonasal small-cell carcinoma. We found higher initial involvement of Levels 2 and 3 and in certain cases to the Level 1 nodal levels, hypothesizing benefit for elective treatment to those levels.

ADVANCES IN KNOWLEDGE

With small single-institution series reporting conflicting nodal involvement rates, our data support high rates of nodal presentation at diagnosis, hypothesizing benefit for elective nodal treatment in this cohort.

Nasal Cavity and Paranasal Sinuses

The nasal cavity and paranasal sinuses occupy the top of the upper respiratory tract and form pneumatic spaces connected with the atmosphere. They are located immediately beneath the base of the cranium, where crucial vital structures are harbored. From this region, very much exposed to airborne agents, arise some of the more complex and rare benign and malignant lesions seen in humans, whose difficulties in interpretation make this remarkable territory one of the most challenging in the practice of surgical pathology.

Contents of this chapter cover inflammations and infections, polyps and pseudotumors, fungal and midfacial destructive granulomatous lesions, as well as benign, borderline, and malignant neoplasms. Among the neoplasms, emphasis is made on those entities characteristic or even unique for the sinonasal region, such as Schneiderian papillomas, glomangiopericytoma, intestinal- and non-intestinal-type adenocarcinomas, olfactory neuroblastoma, nasal-type NK-/T-cell lymphoma, and teratocarcinosarcoma. Moreover, recently recognized entities involving this territory, i.e., HPV-related non-keratinizing carcinoma, NUT carcinoma, and SMARCB1-deficient basaloid carcinoma, are also discussed in the light of their specific molecular findings. Furthermore, the text is accompanied by numerous classical and recent references, several tables, and 100 illustrations.

Activation of aryl hydrocarbon receptor signaling by extracts of teak and other wood dusts

Wood dusts, as a group, are categorized as known human carcinogens, but the risks of exposure to specific types of wood dusts and the carcinogenic chemicals they contain are not well studied. Aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is linked to the carcinogenic action of specific classes of chemicals. Here we examined whether chemicals in various wood dusts had the potential to activate AhR signaling as a potential toxic mechanism of action. We found that methanol extracts of teak, walnut, mahogany, and poplar dusts contained a wide range of AhR ligand activity, whereas extracts of oak, pine, and other softwoods did not contain appreciable activity. Teak dust extract, being particularly potent, was subjected to chemical analysis. The 2-methylanthraquinone (2-MAQ) accounted for the AhR ligand activity and was present at an average concentration of 0.27 parts per hundred in teak dust. Pure 2-MAQ potently induced AhR signaling (EC50 115 nM), confirming that this was the active ligand. Aqueous extracts of teak dust made using yeast or mammalian cell culture medium also contained robust AhR activity, suggesting the 2-MAQ ligand is soluble at bioactive concentrations in physiologically relevant fluids. The high concentration and potency of 2-MAQ in teak wood suggest it may mediate toxic effects through activation of AhR signaling in exposed wood workers.

HPV Infection, but Not EBV or HHV-8 Infection, Is Associated with Salivary Gland Tumours

Benign and malignant salivary gland tumours are clinically heterogeneous and show different histology. Little is known about the role of human herpes virus 8 (HHV-8), Epstein-Barr virus (EBV), and human papillomavirus (HPV) infection in salivary gland neoplasms. We investigated the presence of the three viruses in formalin-fixed, paraffin-embedded tissue samples in a cohort of 200 different salivary gland tumours. We performed EBV-LMP-1 and HHV-8 and p16 immunohistochemistry, a specific chip based hybridization assay for detection and typing of HPV and a chromogenic in situ hybridization for EBV analysis. Only one case, a polymorphic low-grade carcinoma, showed HHV-8 expression and one lymphoepithelial carcinoma was infected by EBV. In 17 cases (9%) moderate or strong nuclear and cytoplasmic p16 expression was detected. The HPV type was investigated in all of these cases and additionally in 8 Warthin's tumours. In 19 cases HPV type 16 was detected, mostly in Warthin's tumour, adenoid cystic carcinoma, and adenocarcinoma NOS. We concluded that HHV-8 infection and EBV infection are not associated with salivary gland cancer, but HPV infection may play a role in these tumour entities.

[Epithelial neuroendocrine tumors of the upper respiratory tract: New entities, new perspectives]

Epithelial neuroendocrine tumors of the upper respiratory tract are rare and are classified as typical and atypical carcinoid versus small cell neuroendocrine carcinoma. Furthermore, a giant cell variant of neuroendocrine carcinoma is suggested corresponding to the bronchopulmonary system as well as a recently described subtype of oropharyngeal small cell neuroendocrine carcinoma associated with human papillomavirus. Many arguments relying on clinical as well as on molecular findings indicate that the distinction between carcinoid and poorly differentiated neuroendocrine carcinoma does not only reflect different degrees of differentiation of otherwise related tumors but indicates the existence of substantially different types of neoplasms.

Treatment outcomes and prognostic factors, including human papillomavirus, for sinonasal undifferentiated carcinoma: a retrospective review

BACKGROUND

Sinonasal undifferentiated carcinoma (SNUC) is a high-grade, aggressive neoplasm. Low incidence and poor outcomes make identification of prognostic factors and treatment standardization difficult. Similarly, little is known regarding the association of human papillomavirus (HPV) with SNUC.

METHODS

A retrospective review was conducted. Extracted information included treatment received, tumor recurrence, patient survival, p16 expression, and HPV status. The Kaplan-Meier method was used to estimate overall survival (OS) and disease-free survival (DFS). Survival trends were compared using the log-rank test.

RESULTS

Nineteen patients received multimodality treatment for SNUC. Five-year OS and DFS rates were 45.2% and 50.7%, respectively, with no significant difference between treatment types. Tumors from 11 patients were p16-positive and 9 of these were also HPV-positive. Kaplan-Meier analysis demonstrated improved survival.

CONCLUSION

Our series demonstrates a higher prevalence of HPV in SNUC than previously reported. HPV-positive SNUCs may benefit from improved survival and should be investigated further in future studies.

Role of p40 and cytokeratin 5/6 in the differential diagnosis of sinonasal undifferentiated carcinoma

Sinonasal undifferentiated carcinoma (SNUC) is an epithelial neoplasm of sinonasal region which does not exhibit a squamous or glandular differentiation. The challenge in diagnosis of this entity is the rarity of the disease, the varying morphology of the tumor which leads to gamut of differential diagnosis and the paucity of consistent immunohistochemical markers except pancytokeratin. Forty-one cases of sinonasal epithelial neoplasm consisting of 11 cases of SNUC and 10 cases each of high-grade (grade 3 and 4) esthesioneuroblastoma, undifferentiated nasopharyngeal carcinoma, and poorly differentiated squamous cell carcinoma of the sinonasal region were analyzed for morphology and immunoexpression of CK5/6 and p40. It was found that SNUC did not exhibit immunohistochemical expression of p40 and CK 5/6, suggesting that these could be useful negative immune markers for diagnosis of SNUC.

The small round blue cell tumors of the sinonasal area: histological and immunohistochemical findings

Background

Primary Small round blue cell tumors (SRBCT) in sinonasal comprise histogenetically diverse entities with overlapping morphologic features. Because of the limited initial biopsy tissue materials, differential diagnostic difficulties may arise, and as they have different management, exact diagnosis and classification are very important.

Objectives

In this study, we analyzed the immunohistochemical expression of a panel of markers in the classification and diagnosis of sinonasal SRBCTs.

Material and Methods

This cross sectional study was performed on 36 paraffin embedded tissue samples. Histologic and immunohistochemical slides from 36 patients with SRBCT were analyzed retrospectively. The patients were admitted in Khalili hospital, Shiraz from 1383 to 1388.

Results

There were 13 women and 23 men with the mean age of 53 ±12.1. There were 9 malignant melanoma, seven poorly differentiated SCC; six lymphoma (DLBL); 4 SCNEC; three SNUC; two ON; two Ewing/PNET; two embryonal rhabdomyosarcoma, and one plasmacytoma. Pan-cytokeratin was strongly expressed poorly differentiated SCC and all cases of SNUC. Coexpression of desmin and nuclear myoD1 was only detected in rhabdomyosarcoma. HMB45 was only expressed in sinonasal melanoma. CD99 expression was identified only in Ewing/PNET. FLI-1 was detected in 50% of PNET. P63 was expressed in poorly differentiated SCC (2/7) and SNUC (1/3).

Conclusions

The results of our study indicate that the integration of histopathologic findings with application of limited but highly specific markers led to the separation of carcinomas, lymphoma and melanomas from other small cell tumors. Using a panel of keratin, LCA, desmin, and HMB45 is the most practical and economic approach to accurately classify these tumors.

Evidence-based practice: endoscopic skull base resection for malignancy

Successful outcomes of endoscopic approaches to benign sinonasal tumors have launched interest in expanding its use for sinonasal malignancy. Because of the heterogeneity and rarity of sinonasal malignancy, evidence for clinical outcomes of endoscopic approaches versus traditional craniofacial resection is low. Using the Oxford Center for Evidence-based Medicine guidelines, we present the existing evidence comparing both techniques for a variety of sinonasal malignancies.

Establishment and characterization of novel cell lines from sinonasal undifferentiated carcinoma

PURPOSE

Sinonasal undifferentiated carcinoma (SNUC) is a rare and aggressive cancer. Despite the use of multimodality treatment, the overall prognosis remains poor. To better understand the biologic features of SNUC and help develop new therapies for the disease, we established SNUC cell lines and characterized their biologic behaviors.

EXPERIMENTAL DESIGN

Cell lines were established from a patient with a T4N0M0 SNUC of the right maxillary sinus who was treated with surgical resection at our center. Tumor colonies were harvested and were sequentially replated onto larger plates. Two populations were developed and labeled MDA8788-6 and MDA8788-7. These cell lines were characterized with molecular, biomarker, functional, and histologic analyses.

RESULTS

Short tandem repeat genotyping revealed that the cell line is isogenic to the parental tumor, and cytogenetic analysis identified 12 chromosomal translocations. The SNUC cell lines do not form colonies in soft agar but are tumorigenic and nonmetastatic in an orthotopic mouse model of sinonasal cancer. Western blot analysis revealed that both MDA8788 cell lines express epithelial markers but do not express mesenchymal markers or the endocrine marker synaptophysin.

CONCLUSIONS

This is the first report of the establishment of stable human-derived SNUC cell lines. The lines were highly tumorigenic and maintain the histologic and molecular features of the original tumor. These cell lines should serve as useful tools for the future study of SNUC biology and the development and testing of novel therapies for this deadly disease.

Sinonasal carcinomas: epidemiology, pathology, and management

Sinonasal carcinomas are uncommon neoplasms accounting for approximately 3% to 5% of all upper respiratory tract malignancies. Sinonasal malignancies in most cases do not cause early symptoms and present in an advanced stage of disease. Exact staging necessitates a clinical and endoscopic examination with biopsy and imaging. Tumor resection using an open or endoscopic approach is usually considered the first treatment option. In general, sinonasal carcinomas are radiosensitive, so adjuvant or neoadjuvant radiation treatment may be indicated in advanced disease. Multidisciplinary surgical and medical oncologic approaches, including ablation and reconstruction, have enhanced the survival outcome over the past few decades.

Sinonasal undifferentiated carcinoma with intracranial extension

AIM

To report our experience in the management of sinonasal undifferentiated carcinoma (SNUC) over a period of 15 years.

STUDY DESIGN

A retrospective case review of 13 patients with SNUC treated at the University of California, Davis, Medical Center (UCDMC) Center for Skull Base Surgery, over the past 15 years.

RESULTS

Most tumors arose in the ethmoid sinuses. All but 1 patient had a combined intracranial-extracranial resection through the anterior fossa-transcranial route and postoperative irradiation. The 13th patient had a transfacial subcranial approach. There are 6 who have survived free of disease at 14 years' to 8 months' follow-up. The average follow-up was 6 years, 3 months. One patient died of a pulmonary embolism in the first postoperative week, a second died of a bowel infarction 3 months postoperatively. Three patients died of their disease at 20, 18, and 8 months postoperatively: 1 with local recurrence and distant metastasis and the other 2 with local control but distant disease. The 6 survivors are at 8, 20, 28, 62, 84, and 105 months.

CONCLUSION

SNUC is a rare malignancy of the paranasal sinuses with a poor prognosis. Radical surgery and adjunctive therapy can achieve good survival in a significant proportion of patients who would hitherto have seemed incurable.

Meta-analysis of treatment outcomes for sinonasal undifferentiated carcinoma

OBJECTIVES

This study reviews the published outcomes regarding sinonasal undifferentiated carcinoma (SNUC) since the initial description in 1986. This article attempts to (1) understand and better describe the benefit and survival advantages associated with using radiation, chemotherapy, and surgical treatment and (2) support the recommendations of a treatment regimen with current available data in the literature.

DATA SOURCES

Published English-language literature.

REVIEW METHODS

A PubMed search for articles related to SNUC, along with the bibliographies of those articles to avoid missing articles. All articles were examined for an independent patient data meta-analysis. Thirty studies with 167 cases from 1986 to October 2009 were identified. Demographics, disease extent, treatment, follow-up, and survival were analyzed. Patient cohorts mirroring Kadish staging were created. Kaplan-Meier curves were constructed.

RESULTS

Follow-up range was 1 to 195 months (mean 23.4 months, median 15 months). At last follow-up, 26.3% of patients were alive with no evidence of disease, 21.0% were alive with disease, and 52.7% were dead of disease. The use of surgery was found to be the best single modality, but chemotherapy and radiation were important as adjuncts in extensive and aggressive disease. The presence of neck metastases was a poor prognostic sign.

CONCLUSION

This study, containing the largest pool of SNUC patients, confirms a poor overall prognosis. The data suggest that the optimal treatment should include surgery, with radiation and/or chemotherapy as adjunct treatments. Neck disease in advanced local disease is a poor prognostic sign and merits aggressive treatment with multimodality therapy.

Endoscopic skull base surgery for sinonasal malignancy

Management of malignant neoplasms of the sinonasal tract and skull base is hampered by the relative low incidence and pathologic diversity of patient presentations. Many studies have reported successful outcomes in the endoscopic management of malignancy since 1996, and these are summarized in this article. Nonsurgical adjuvant therapies are important for locoregional control because surgery occurs in a restricted anatomic space with close margins to critical structures, and distant disease is an ongoing concern in these disorders. There remains a need for collaborative consistent multicenter reporting, and international registries have been established to assist in such efforts.

Calretinin staining facilitates differentiation of olfactory neuroblastoma from other small round blue cell tumors in the sinonasal tract

OBJECTIVE

Olfactory neuroblastoma (ONB) is an uncommon malignant tumor of the sinonasal tract and has a wide histologic differential diagnosis that includes other small round blue cell tumors (SRBCTs). Even with the use of immunohistochemistry (IHC), the correct diagnosis may be difficult, especially in small biopsies. The purpose of this study is to determine the usefulness of calretinin and p63 as an aid to distinguish ONB from other sinonasal SRBCTs.

METHODS

IHC staining for calretinin and p63 was performed on 21 specimens diagnosed as ONB and on 42 other sinonasal SRBCTs. Specimens were retrieved from the files of the QEII HSC, Halifax and UHN, Toronto.

RESULTS

All but 1 ONB (20 of 21) showed calretinin staining, with 15 of 21 showing staining in >75% of the tumor area and 18 of 21 showing moderate-to-strong staining intensity. Only pituitary adenomas (3 of 3) and a single case of small cell carcinoma, neuroendocrine type (1 of 2), showed a similar staining pattern. None of the ONBs showed staining for p63. P63 was positive in all cases of nonkeratinizing squamous cell carcinoma (2 of 2) and in single cases of mantle cell lymphoma (1 of 1) and poorly differentiated neuroendocrine carcinoma (1 of 1); however, it inconsistently stained diffuse large B-cell lymphoma (4 of 5), extranodal NK/T-cell lymphoma, nasal type (1 of 4), sinonasal undifferentiated carcinoma (1 of 6), and Ewing sarcoma/primitive neuroectodermal tumor (2 of 6).

CONCLUSIONS

Calretinin appears to be a useful marker to distinguish ONBs from other SRBCTs of the sinonasal tract, particularly when staining is moderate/strong and extensive. The calretinin-positive, p63-negative phenotype is fairly specific for ONB. The addition of these 2 IHC stains may aid in the diagnosis of sinonasal SRBCTs that are poorly differentiated, have inconclusive conventional IHC, or are found in small biopsies.

Select Neoplasms of the Sinonasal Tract

The sinonasal tract (SNT) includes the nasal cavity and paranasal sinuses (maxillary, ethmoid, frontal, and sphenoid) and may give rise to a variety of nonneoplastic and neoplastic proliferations, including benign and malignant neoplasms. The benign neoplasms of the SNT include epithelial neoplasms of surface epithelial origin, minor salivary gland origin, and mesenchymal origin. The spectrum of malignant neoplasms of the SNT includes epithelial malignancies, sinonasal undifferentiated carcinoma, malignant salivary gland neoplasms, neuroectodermal neoplasms, neuroendocrine neoplasms, melanocytic neoplasm, and sarcomas. This article concentrates on some of the more common types of benign and malignant neoplasms.

Expression of p16 in sinonasal undifferentiated carcinoma (SNUC) without associated human papillomavirus (HPV)

Sinonasal undifferentiated carcinoma (SNUC) is an uncommon and highly aggressive neoplasm of the paranasal sinuses and nasal cavity. Its undifferentiated histologic appearance often requires immunohistochemical studies to distinguish it from other high-grade neoplasms. Due to the rarity of SNUC, its immunohistochemical staining profile has been incompletely characterized, and little work has been done on its expression of the markers for human papillomavirus (HPV). Our objective is to expand our knowledge of its immunophenotype and its association with HPV in order to define markers with mechanistic potential in the disease process, or of possible therapeutic importance. A total of five patients (one woman and four men) with SNUC, ranging in age from 26 to 75 years (mean 56.8 years) were compared to five patients (five men) with poorly differentiated squamous cell carcinoma (PDSCC), ranging in age from 53 to 75 years (mean 62.2 years). PDSCC was chosen as a control, given its well-reported immunohistochemical profile and negativity for HPV markers. The immunohistochemical panel included: CK7, CK19, EMA, NSE, chromogranin, p53, CK5/6, p63, CK14, S100, HMB-45, desmin, muscle specific actin, and CD45. Additionally, tests for p16, EBV, and HPV (subtypes 6, 11 16, 18) were performed. The diagnosis of SNUC was confirmed in all cases by histology and immunohistochemical stains. An interesting finding of strong diffuse positivity for p16 was noted in all SNUC cases, compared to only two of five PDSCC that were positive for p16. HPV DNA was not detected in any SNUC cases or any cases of PDSCC. All SNUC cases demonstrated over expression of p16 in the absence of HPV DNA expression. This may represent residual epithelial p16 staining, which is normally present in the sinonasal tract. Due to the rarity of SNUC, more cases will need to be evaluated to confirm the absence of HPV DNA.