Outcomes in surgical management of sinonasal malignancy-A single comprehensive cancer center experience.

BACKGROUND: Sinonasal malignancies are a complex and diverse group of tumors. Over the past five decades, treatment advances have changed the management paradigms for these tumors. Our aim was to analyze the outcomes of patients from a comprehensive cancer center. MATERIALS AND METHODS: We retrospectively assessed 400 patients with sinonasal malignancies treated with surgery at our center between 1973 and 2015. Multiple variables were reviewed to assess the influence on 5-year outcomes. RESULTS: The median age was 56 years (IQR 46.8-68). Two hundred and fifty-nine (65%) were males and 141 (35%) were females. Overall survival (OS) and disease-specific survival (DSS) improved in the last analyzed decade. Orbital invasion, advanced pT-classification and pN-classification, and melanoma histology were associated with poorer outcomes. CONCLUSION: Treatment outcomes for patients with sinonasal malignancy have improved over time. This is likely multifactorial with advances in surgical technique, adjuvant treatment, and patient selection. pT-classification, pN-classification, orbital invasion, and histology are predictive of survival.

Three-dimensional printed definitive cast for a silicone obturator prosthesis: A clinical report.

For patients with head and neck cancer requiring a maxillectomy, obturator prostheses help with quality of life. These patients routinely require adjuvant oncologic treatments with significant adverse effects. Treatment sequelae can leave patients with difficulty speaking and swallowing, reduced salivary function, reduction in maximal incisal opening, and at risk of osteoradionecrosis. A 55-year-old African-American woman presented with significant trismus and reduction in maximal incisal opening after treatment for squamous cell carcinoma of the left maxillary sinus. She had received a left total maxillectomy with adjuvant chemotherapy and radiation treatments. With her reduced opening, she was no longer able to insert her interim obturator prosthesis, which caused difficulty speaking and nasal regurgitation. A cone beam computed tomography scan was made of the patient's maxillectomy defect. From the Digital Imaging and Communications in Medicine file, a definitive cast was 3-dimensionally printed to fabricate a flexible silicone obturator prosthesis. This treatment has allowed the patient to return to a functional quality of life and could help other patients in similar situations.

Inflammatory Myofibroblastic Tumors in Paranasal Sinus and Nasopharynx: A Clinical Retrospective Study of 13 Cases.

BACKGROUND: Inflammatory myofibroblastic tumor (IMT), as a mesenchymal tumor, is common in the lung and abdomen but rare in the paranasal sinus and nasopharynx. OBJECTIVE: This study aimed to summarize the clinical characteristics of IMT in the paranasal sinus and nasopharynx and analyze the relationship between the treatment and the overall survival (OS). METHOD: The clinical features, treatment, and follow-up data of patients diagnosed with IMT of the paranasal sinus or nasopharynx from 2006 to 2017 were retrospectively analyzed, and the previous literature was reviewed. RESULTS: IMT often presents as an ill-defined soft-tissue mass with bone destruction and invasion of surrounding structures. The treatment methods used in this study were different combinations of surgery, prednisone, radiotherapy, and chemotherapy or observation alone. Three of the 13 patients were lost and the follow-up time of the remaining 10 cases ranged from 2 to 87 months (median, 39 months). Two patients died of the disease; the other eight patients were stable. The 5-year survival rate was 72%. Among the four methods of treatment, only treatment with prednisone was significantly correlated with better OS (P = 0.046). CONCLUSIONS: IMT is an intermediate tumor that often mimics malignancy. We are not sure if IMTs in the nasal cavity are more aggressive because of the biology or if the location and local therapy in the head region is more complicated. Radiologic findings help know the extent of the lesion. For unresectable nasal IMT, combined therapy with glucocorticoids, chemotherapy, and radiotherapy is sometimes a better choice. Glucocorticoids are especially recommended as a basic part of the integrated therapy. However, the standard treatment needs further research.

Trans-Frontal Five-Fluorouracil (TraFFF): a novel technique for the application of adjuvant topical chemotherapeutic agents in sinonasal adenocarcinoma.

Sinonasal adenocarcinoma has traditionally been treated with surgery (craniofacial or endoscopic) and adjuvant radiotherapy. Two large series have demonstrated favourable 5-year survival using surgery with adjuvant topical chemotherapy applied repeatedly over several weeks. The authors describe a novel, transnasal application of topical 5-fluorouracil. However, complete coverage of the frontal region of the anterior skull base can be difficult to achieve with a purely transnasal approach in an outpatient setting. We present a novel adjunct method of delivering chemotherapeutic agents into this key area used in a 37-year-old man with T2N0M0 ethmoid adenocarcinoma. The procedure was well tolerated in an outpatient setting and remains disease free at 3 years postoperatively. We suggest that frontal trephination is a useful adjunct to aid accurate placement of adjuvant topical chemotherapeutic agents in the treatment of sinonasal adenocarcinoma.

AHNS Series: Do you know your guidelines? Principles for treatment of cancer of the paranasal sinuses: A review of the National Comprehensive Cancer Network guidelines.

This article is a continuation of the "Do You Know Your Guidelines" series. This was launched as an initiative of the American Head and Neck Society to increase the awareness of current best practices pertaining to head and neck cancer. The National Comprehensive Cancer Network (NCCN) guidelines for managing cancer of the paranasal sinuses are reviewed in a systematic fashion. These guidelines outline the workup, treatment, and surveillance of patients with cancer of the maxillary and ethmoid sinuses.

Paleopathological evidence of paranasal lesions: Two cases of frontal sinus osteomata from Imperial Rome.

The archaeological excavations carried out in 1999 in the Collatina necropolis of the Roman Imperial Age (1st-3rd centuries AD) (Rome, Italy) discovered the skeletal remains of two adult males with evidence of paranasal lesions. Both individuals showed postmortem damage in the frontal bone, through which it was possible to macroscopically detect an oblong new bone formation. In both specimens, radiological examination of the defects' morphology showed new pediculated-based bone formations. Radiology also confirmed the presence of benign osseous masses arising from the right frontal sinus and interpreted as osteomata. Their dimensions did not exceed 10 mm, so that mechanical complications and compression of the adjacent structures could be ruled out. The osteomata of paranasal sinuses are rarely reported in paleopathology, since they can be discovered only incidental to bone breakage or radiography. Hence, the evaluation of their occurrence in past populations represents an important challenge. The two cases presented here show direct and rare evidence of frontal sinus osteomata dating back to the Roman Imperial Age.

Clinical management of squamous cell carcinoma associated with sinonasal inverted papilloma.

OBJECTIVE: The aim of this study was to investigate the clinical features and prognosis of patients with squamous cell carcinoma (SCC) associated with sinonasal inverted papilloma (IP). METHODS: The medical records of 95 patients who were diagnosed with IP or SCC associated with IP were retrospectively reviewed. Out of 95 patients, 15 were diagnosed with SCC associated with IP. The clinical characteristics, treatment modalities, and survival outcomes of the patients were analyzed. RESULTS: The incidence of SCC associated with IP was 15.8%. Although differential diagnosis between IP and SCC associated with IP is difficult, epistaxis may be the specific symptom in SCC associated with IP cases. The 3-year disease-specific survival rate was higher in cases with T1, 2 and 3 than in cases with T4. There was no significant difference in survival rate between maxillary sinus and other primary sites. On the other hand, there was a significant difference in survival rate between the microscopic SCC with IP cases and the other cases. In addition, the patients with <70 years old better than those with >70 years old with a 3-year disease free survival of 80% versus 0%. CONCLUSIONS: Some T4 patients were found to have a highly aggressive disease. Therefore, complete surgical resection followed by chemo-radiation therapy is the recommended treatment for patients with T4 disease to control of the primary tumor site.

[Nasal cavity and paranasal sinus cancer]. / Radiothérapie des cancers des cavités nasosinusiennes.

The nasal cavity and parasinusal cancer are rare (10% of tumors of the head and neck) and are mainly represented by squamous cell carcinoma of the nasal cavity or the maxillary sinus and adenocarcinoma of the ethmoid sinus (occupational disease, wood dust). The most common clinical sign is nasal obstruction, but tumors can also manifest as rhinorrhea and/or epistaxis (usually unilateral signs). A magnetic resonance imaging of the facial structure is systematic for staging before treatment. The treatment consists of a first surgery if the patient is operable with a resectable tumor. If it is not the case, the treatment consists of radiotherapy (RT) associated with chemotherapy (CT) according to the initial data (T3/T4 or N+). After first surgery, RT is indicated (except T1N0 with complete resection) associated with a CT based on postoperative data (capsular effraction or incomplete resection). Lymph node irradiation is considered case by case, but is indicated in any nodal involvement. RT must be an intensity modulated RT (IMRT), static or dynamic, and must be imagery guided (IGRT). According to ICRU 83, doses to organs at risk and target volumes must be carried. Finally, after a post-treatment baseline imaging between 2 and 4 months, monitoring will be alternated with the ENT surgeon every 2 or 3 months for 2 years, then every 4 to 6 months for 5 years.

Induction chemotherapy in head and neck squamous cell carcinoma of the paranasal sinus and nasal cavity: a role in organ preservation.

BACKGROUND/AIMS: The role of induction chemotherapy (IC) for eyeball preservation has not been established in head and neck squamous cell carcinoma (HNSCC) of the paranasal sinus and nasal cavity (PNSNC). Periorbital involvement frequently leads to eyeball exenteration with a margin of safety. We evaluated the treatment outcomes, including survival and eyeball preservation, of patients who received IC for HNSCC of the PNSNC. METHODS: We reviewed 21 patients diagnosed with HNSCC of the PNSNC who were treated with IC. We analyzed response, eyeball preservation rate, and overall survival. RESULTS: Tumors were located in the paranasal sinus (n = 14) or nasal cavity (n = 7). Most patients had stage T4a (n = 10) or T4b (n = 7) disease. More than half of the patients received a chemotherapy regimen of docetaxel, fluorouracil, and cisplatin (n = 11). Thirteen patients (61.9%) achieved a partial response after IC and 15 patients (71.4%) achieved T down-staging. Among 17 patients with stage T4 disease, which confers a high risk of orbital exenteration, 14 (82.4%) achieved preservation of the involved eye. The 3-year overall survival (OS) rate of patients who achieved a partial response to IC was 84.6%. The 3-year OS rate of patients with stable disease or disease progression after IC was 25.0% (p = 0.038). CONCLUSIONS: IC could be considered for down-staging patients with advanced T-stage disease. It could also be a reasonable option for eyeball preservation in locally advanced HNSCC of the PNSNC.

Customized individual applicators for endocavitary brachytherapy in patients with cancers of the nasal cavity, sinonasal region and nasopharynx.

Brachytherapy has become an established therapeutic regimen for primary, persistent, recurrent and metastatic tumour disease in the head and neck region. This study presents the authors' preliminary experience with intracavitary brachytherapy by means of an individual silicone applicator in the treatment of patients with nasal, sinonasal, orbital and nasopharyngeal cancer. Between January 2001 and January 2013, twenty patients with cancer of the nasal cavity, the paranasal sinuses and nasopharynx underwent surgery and intracavitary brachytherapy with the aid of an individually manufactured silicone applicator in the Department of Otolaryngology, Head and Neck Surgery and in the Department of Radiotherapy and Radiooncology at the Saarland University Medical Center of Homburg, Germany. The tumour was localized in the nasal cavity/paranasal sinuses (15) affecting the orbit twice and the nasopharynx (5). There were 14 patients with squamous cell carcinoma, 2 patients with mixed tumours and one patient with adenocarcinoma, adenoid cystic carcinoma, mucosal melanoma or plasmocytoma. The majority of the patients presented with advanced disease (T3 or T4 tumours). In 18/20 patients, brachytherapy was performed as a boost technique, in the remaining two solely because of a previous radiation series. All surgical interventions were performed endonasally. Three to six weeks after surgery, a cast of the nasal cavity was created under general anaesthesia. Subsequently, an individual brachytherapy silicon applicator with two to four plastic tubes was manufactured. The radiation therapy was applied using the Ir-192 high-dose-rate-afterloading method (total dose 10-20 Gy) in two to five sessions, additionally in 18/20 patients a percutaneous radiotherapy with a total dose of 30-60 Gy was applied. After a mean duration of follow-up of 2 years, 7/20 patients experienced a local progression, 5/19 a regional recurrence in the neck nodes and 4/19 distant metastases. The 2-year survival was 57.3 %. No serious complications were reported. The silicone applicator was well tolerated by all patients. Because of the complexity of the sinonasal anatomy with the finding of mainly advanced tumours, the presented individual silicone brachytherapy applicator has proven to be useful and meaningful for endocavitary brachytherapy of malignancies of the nasal cavities, paranasal sinuses and nasopharynx.

Management for squamous cell carcinoma of the nasal cavity and ethmoid sinus: A single institution experience.

OBJECTIVE: Here we report our experience of patients with squamous cell carcinoma (SCC) of the nasal cavity and ethmoid sinus (NC&ES) together with an analysis of treatment outcomes. METHODS: A retrospective analysis was performed using data from 25 consecutive patients treated between 2000 and 2012. Four patients were diagnosed with T1, 3 with T2, 4 with T3, 7 with T4a, and 7 with T4b disease. No patient had lymph node metastasis. RESULTS: Twelve patients were treated with surgery with/without radiotherapy and with/without chemotherapy. Of these, 4 underwent endoscopic surgery without an open approach and 3 required an anterior skull base approach. Thirteen were treated with radiotherapy; 1 with radiotherapy alone, and 4 and 8 with intravenous and intra-arterial chemotherapy, respectively. The 5-yr overall survival for T1-3, T4a, and T4b disease was 53.9%, 71.4%, and 29.0%, respectively. The 5-yr disease-specific survival for T1-3, T4a, and T4b disease was 74.1%, 71.4%, and 29.0%, respectively. CONCLUSION: Our treatment policy for patients with SCC of NC&ES, which basically follows the NCCN guideline, was considered to be appropriate. However, several points in terms of surgery and non-surgical approach remain to be solved through further research.

Outcomes of endonasal endoscopic dacryocystorhinostomy after maxillectomy in patients with paranasal sinus and skull base tumors.

Maxillectomy followed by radiotherapy and/or chemotherapy can result in lacrimal blockage and the need for subsequent dacryocystorhinostomy (DCR). Endonasal endoscopic DCR, as opposed to external DCR, allows better accuracy and leaves no scar. To date no report was published regarding the results of endoscopic DCR in these patients. The current study presents a retrospective review of all patients with paranasal and skull base tumors who developed nasolacrimal duct blockage after ablative maxillectomy with or without radiotherapy and/or chemotherapy and underwent endonasal endoscopic DCR between January 2006 and October 2012 in a tertiary reference medical center. According to our results, ten patients underwent 11 subsequent endonasal endoscopic DCR. There were 6 men and 4 women with a median age of 55 years (range, 19-81 years); four suffered from benign tumors and six had malignant tumors. All underwent maxillectomy. Six received high-dose radiotherapy. Time interval between primary ablative surgery and endonasal endoscopic DCR was 18 months (range, 7-118 months). Silicone stents were removed after median period of 11 weeks (range, 1-57 weeks). Nine out of ten patients experienced symptomatic improvement following one endonasal endoscopic DCR. One patient had recurrent epiphora and underwent a successful endonasal endoscopic revision DCR. In conclusion, endonasal endoscopic DCR in patients with paranasal and skull base tumors, who previously underwent maxillectomy, is generally successful and not associated with a high rate of complications or failure. Moreover, our findings may suggest that silicone stents can be removed shortly after the operation with high success rate.

[Advances in head and neck cancers on behalf of the French Intergroup ORL and GORTEC]. / Évolution des concepts dans les cancers des voies aérodigestives supérieures, sous l'égide de l'Intergroupe ORL (GORTEC, GETTEC, GERCOR).

Head and neck cancers are the fifth among the most common cancers in France. Two thirds of cases occur at an advanced stage. For advanced disease, progression-free survival, despite undeniable progress, remains below 50% at three years. The last 20 years have been marked by the necessity to identify situations where less intense surgery and/or radiotherapy and/or chemotherapy is possible without jeopardizing the prognosis, and situations where a therapeutic intensification is necessary and results in a gain in survival while better preserving function with less toxicity. French cooperative groups gathering radiation oncologists (GORTEC), surgeons (GETTEC) and medical oncologists or physicians involved in the management of systemic treatments in head and neck cancers (GERCOR) are now belonging to the INCa-labelled Intergroup ORL to deal with the challenges of head and neck cancers.

Tp53 status as guide for the management of ethmoid sinus intestinal-type adenocarcinoma.

OBJECTIVE: Intestinal-type adenocarcinoma (ITAC) of the ethmoid sinus is a rare, occupational-related tumor. Optimal treatment consists of surgery and radiotherapy, while chemotherapy is still investigational. The molecular profile of ITAC is characterized by the occurrence of TP53 mutations associated with genotoxic agents such as wood dust. We investigated the role of p53 functionality in relation to the primary treatment. MATERIALS AND METHODS: We retrospectively reviewed 100 medical charts of consecutive patients with a first diagnosis of ITAC treated at our Institute; 74 patients were evaluable for TP53 analysis. Thirty (41%) were treated from 1991 to 2006 with craniofacial resection followed by radiotherapy (Group A), compared with 44 patients (59%) treated from 1996 to 2006 with cisplatin-based induction chemotherapy (PFL) followed by standard treatment (Group B). RESULTS: Five-year OS in Group A was 42%, while in Group B it was 70% (p = 0.041); 5-year DFS in Group A was 40%, while in Group B it was 66%, (p = 0.009) (p = 0.061 and 0.003 at Cox multivariable OS and DFS analyses). Analyzing each group according to p53 functional status, only for Group B patients (who received preoperative chemotherapy) both OS and DFS were in favor of functional p53 (p = 0.023 and p = 0.010, respectively). No impact of p53 functional status as a biomarker was observed in Group A. CONCLUSIONS: Functional p53 may predict PFL-chemotherapy efficacy, offering a possible increase in survival when induction chemotherapy is given to a selected population. On the other hand, upcoming innovative approaches should be explored in the presence of non-functional p53.

[Endoscopic surgery for advanced malignant nasal and sinus tumors].

OBJECTIVE: To evaluate the effect of endoscopic surgery for advanced malignant tumors in the nasal cavity and paranasal sinuses. METHODS: A retrospective data analysis was performed on 49 patients with advanced sinonasal tumors undergoing either an exclusive endoscopic approach or with a complemental approach from January 2004 to October 2010. Forty-nine patients were considered eligible for the present analysis, among them, T3:T4a:T4b were 12:13:24 (T stage was assessed with the sixth editions of the UICC staging systems). The histotypes encountered were squamous cell carcinoma 20 cases, adenocarcinoma 12 cases, mucosal melanoma 8 cases, olfactory neuroblastoma 6 cases, others 3 cases. These patients were operated on either by an exclusive endoscopic endonasal approach or with a complementary external approach; 36 patients received adjuvant radiotherapy or/and chemotherapy. The data were analyzed by Kaplan-Meier method and Log-rank test. RESULTS: The hemorrhage varied from 200 to 5000 ml during the operation, with an average of 600 ml. The post-operative complications were rare, 1 patient lost her sight after operation, and no patient got infected at the site of operation (nor intracranial infection). After full amount of radiotherapy, no cerebrospinal fluid rhinorrhea was found. Four patients (8.2%) lost to follow-up. Sixteen patients died during the follow-up period, only three of them were without craniocerebral or orbital invasion. Four in 9 patients in the other pathological group (with the pathology of olfactory neuroblastoma or glioma etc), which had a poor prognosis, died during the follow-up period, of them, 3 had definitive evidence of intracranial metastasis, and none of the nine patients had been followed-up beyond 25 months. The 2 and 3 year disease-free rates were 34.2% and 21.4%, and overall survival rates were 62.5% and 58.4% respectively. The T stage, margin status, and whether accepted post operative adjuvant therapy were significant factors in predicting disease recurrence (χ² were 7.7, 4.9, 6.8 respectively and P < 0.05). CONCLUSIONS: Now the endoscopic techniques with or without complementary approaches is an effective way for complete tumor removal. With postoperative complementary therapy, it provides a satisfactory survival rate with few side effects and better quality of life.

Endoscopic surgery for advanced malignant nasal and sinus tumors / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To evaluate the effect of endoscopic surgery for advanced malignant tumors in the nasal cavity and paranasal sinuses.</p><p><b>METHODS</b>A retrospective data analysis was performed on 49 patients with advanced sinonasal tumors undergoing either an exclusive endoscopic approach or with a complemental approach from January 2004 to October 2010. Forty-nine patients were considered eligible for the present analysis, among them, T3:T4a:T4b were 12:13:24 (T stage was assessed with the sixth editions of the UICC staging systems). The histotypes encountered were squamous cell carcinoma 20 cases, adenocarcinoma 12 cases, mucosal melanoma 8 cases, olfactory neuroblastoma 6 cases, others 3 cases. These patients were operated on either by an exclusive endoscopic endonasal approach or with a complementary external approach; 36 patients received adjuvant radiotherapy or/and chemotherapy. The data were analyzed by Kaplan-Meier method and Log-rank test.</p><p><b>RESULTS</b>The hemorrhage varied from 200 to 5000 ml during the operation, with an average of 600 ml. The post-operative complications were rare, 1 patient lost her sight after operation, and no patient got infected at the site of operation (nor intracranial infection). After full amount of radiotherapy, no cerebrospinal fluid rhinorrhea was found. Four patients (8.2%) lost to follow-up. Sixteen patients died during the follow-up period, only three of them were without craniocerebral or orbital invasion. Four in 9 patients in the other pathological group (with the pathology of olfactory neuroblastoma or glioma etc), which had a poor prognosis, died during the follow-up period, of them, 3 had definitive evidence of intracranial metastasis, and none of the nine patients had been followed-up beyond 25 months. The 2 and 3 year disease-free rates were 34.2% and 21.4%, and overall survival rates were 62.5% and 58.4% respectively. The T stage, margin status, and whether accepted post operative adjuvant therapy were significant factors in predicting disease recurrence (χ² were 7.7, 4.9, 6.8 respectively and P < 0.05).</p><p><b>CONCLUSIONS</b>Now the endoscopic techniques with or without complementary approaches is an effective way for complete tumor removal. With postoperative complementary therapy, it provides a satisfactory survival rate with few side effects and better quality of life.</p>

[Influence of chemotherapy regimen on antioxidant level in patients with locally-advanced tumors of the maxilla, nasal and paranasal sinuses].

The study dealt with effect of chemoradiotherapy on the oxidant/antioxidant system in 57 patients with locally-advanced tumors (stage III-IV) of the maxilla, nasal and paranasal sinuses. Therapy modalities ranged from systemic chemoradiotherapy (22), intraarterial chemoradiotherapy + UHF-hyperthermia (20) and intraarterial chemotherapy + radiotherapy (15). The most frequent regimen of chemotherapy involved cisplatin 15 mg/ m2, total dose of 100 mg; fluorouracil 600 mg/m2, total dose of 2,000-3,000 mg, and doxorubicin 15 mg/m2, total dose of 40-60 mg. As far as telegammatherapy is concerned, all patients received STD of 3 Gy and TTD of 40-60 Gy. Unlike systemic chemoradiotherapy, continuous intraarterial chemoradiotherapy with UHF-hyperthermia or without it was followed by lower incidence of enhanced oxidative reaction response and tumor-related endotoxicosis.

Sinonasal tumor in 3 dogs after successful topical treatment for frontal sinus aspergillosis.

Three dogs diagnosed with aspergillosis developed sinonasal tumors several months after successful treatment with topical clotrimazole solution. Chronic rhinosinusitis was also detected in all cases prior to diagnosis of sinonasal tumors. The inflammatory response to Aspergillus, clotrimazole treatment, and chronic inflammation after treatment are discussed as possible neoplastic promoting factors.

A limited immunohistochemical panel helps differentiate small cell epithelial malignancies of the sinonasal cavity and nasopharynx.

BACKGROUND: Distinguishing small cell epithelial malignancies of the sinonasal cavity and nasopharynx is difficult due to overlapping morphologic characteristics, particularly in small biopsies. This distinction is important, however, because of the inherent differences in biology, natural history, prognosis, and treatment among these neoplasms. The aim of this study is to identify a limited immunohistochemical panel that may help to differentiate these morphologically similar small cell epithelial malignancies. DESIGN: We reviewed 37 cases of histologically similar small cell epithelial malignancies of the sinonasal cavity and nasopharynx: nasopharyngeal carcinoma (NPC) (16), basaloid squamous cell carcinoma (BSCC) (15), and high-grade neuroendocrine carcinoma (HGNEC) (6) obtained at Jackson Memorial Hospital/UM Sylvester Comprehensive Cancer Center between 2003 and 2007. Immunohistochemistry for pancytokeratin (CK), CK5/6, p63, and HLA-DR was performed using the labeled streptavidin-biotin method. RESULTS: All cases in this study were positive for CK and p63. The CK staining pattern of HGNEC was characteristically dot-like whereas the remaining tumors stained with strong and diffuse cytoplasmic membrane positivity. Likewise, the p63 staining pattern of HGNEC was focal and weak whereas the remaining tumors stained with diffuse and strong nuclear positivity. Immunohistochemistry for HLA-DR was positive in all cases of NPC, whereas BSCC and HGNEC were uniformly negative. Cases of NPC and BSCC were positive for CK5/6 whereas cases of HGNEC were negative. CONCLUSIONS: A limited immunohistochemical panel of CK, CK5/6, p63, and HLA-DR is useful in discriminating nasopharyngeal, basaloid squamous cell, and high-grade neuroendocrine carcinomas of the sinonasal cavity and nasopharynx.