Lymphoepithelial-like carcinomas of the head and neck

Histopathologic, Molecular, and Clinical Profiling of Lymphoepithelioma-like Carcinoma of the Bladder

Lymphoepithelioma-like carcinoma of the bladder (LELC-B) is a rare histologic subtype characterized by strong immune cell (IC) infiltrates. A better prognosis and favorable response rates to immune checkpoint inhibitors have been described. We aimed to characterize the molecular profiles and IC infiltration of LELC-B for a better understanding of its therapeutic implications. We identified 11 muscle-invasive bladder cancer cases with pure and mixed LELC-B. Programmed cell death ligand-1 (PD-L1) expression and mismatch repair proteins were evaluated using immunohistochemistry. We calculated the tumor mutational burden and characterized mutational profiles using whole-exome DNA sequencing data. Transcriptomic signatures were detected using the NanoString nCounter PanCancer IO360 Panel. Multiplex immunofluorescence of tumor microenvironment (PD-L1, PanCK, α-SMA, vimentin, CD45, and Ki67) and T cells (CD4, CD3, PD-1, CD163, CD8, and FoxP3) was used to quantify cell populations. All LELC-B cases were highly positive for PD-L1 (median tumor proportion score/tumor cell, 70%; range, 20%-100%; median combined positive score, 100; range, 50-100) and mismatch repair proficient and negative for Epstein-Barr virus infection. IC infiltrates were characterized by a high CD8+ T-cell count and high PD-1/PD-L1 expression on immune and tumor cells. LELC-B showed upregulation of signaling pathways involved in IC response. Most common mutations were found in chromatin remodeling genes causing epigenetic dysregulation. All LELC-B cases showed high tumor mutational burden with a median of 39 mutations/Mb (IQR, 29-66 mutations/Mb). In conclusion, LELC-B is a highly immunogenic tumor, showing strong upregulation of PD-1/PD-L1 and making immune checkpoint inhibitors a promising treatment option.

Lymphoepithelial carcinoma of the parotid gland

Primary lymphoepithelial carcinoma of the salivary glands is an exceptional oncological condition that predominantly emerges within the parotid gland. A significant prevalence of lymphoepithelial carcinoma has been reported in the Inuit population, along with an associated positive serology for Epstein-Barr virus in these endemic regions. In this paper, we present a case of primary lymphoepithelial carcinoma of the parotid gland in a 68-year-old female patient with a history of diabetes and hypertension residing in a non-endemic area. Histology plays a critical role in the definitive diagnosis, and confirming the primary origin of lymphoepithelial carcinoma after ruling out metastasis from undifferentiated nasopharyngeal carcinoma. The mainstay of treatment is a combination of surgical resection and adjuvant radiotherapy. Inoperable forms are typically managed with chemoradiotherapy.

Challenging Tumor Heterogeneity with HER2, p16 and Somatostatin Receptor 2 Expression in a Case of EBV-Associated Lymphoepithelial Carcinoma of the Salivary Gland

BACKGROUND

Lymphoepithelial carcinoma of the salivary glands (LECSG) is a rare disease in the Western hemisphere that is typically associated with an EBV infection. The molecular mechanisms of LECSG tumorigenesis are poorly understood.

RESULTS

Here we report a case of EBV-associated LECSG with an unusual immunophenotype. The tumor exhibited bi-morphic histological features with a mutually exclusive expression of HER2 and p16. The p16-positive domain of the tumor immunohistochemically co-expressed late membrane protein 1 (LMP-1), while the HER2 positive domain did not. Both tumor regions expressed SSTR2.

METHODS

In situ hybridization confirmed the EBV origin of the tumor while extensive immunohistochemical characterization and the recently established RNA-based next generation sequencing panel ("SalvGlandDx" panel) did not reveal evidence for another salivary gland neoplasm. No HPV co-infection was detected by in situ hybridization or PCR-based screenings and no ERBB2 gene amplification was detected by fluorescence in situ hybridization.

CONCLUSION

These findings suggest tumor heterogeneity and lack of genomic aberrations in EBV-associated LECSGs. The heterogenous and unusual immunohistochemical features explain the diagnostic difficulties and simultaneously extend the immunophenotype spectrum of this tumor entity.

The role of postoperative radiotherapy (PORT) in lymphoepithelial carcinoma of the salivary gland (LECSG) and the effect of postoperative EBV DNA on prognosis

BACKGROUND

Whether postoperative radiotherapy (PORT) could improve survival and the role of EBV DNA remains unclear for patients with lymphoepithelial carcinoma of the salivary glands (LECSG).

PATIENTS AND METHODS

360 patients were included. Independent prognostic factors were selected using a Cox proportional hazards model and incorporated into risk stratification.

RESULTS

The number of positive lymph nodes (PLNs) ≥ 3 and tumor size ≥ 3 cm were independent factors for PFS in patients with neck dissection (ND). Patients were divided into three groups: high-risk, size ≥ 3 cm&PLNs ≥ 3; intermediate-risk, size < 3 cm&PLNs ≥ 3 or size ≥ 3 cm&PLNs < 3; low-risk, size < 3 cm&PLNs < 3. The 5-year PFS rate of the low-, intermediate- and high-risk patients receiving non-PORT and PORT was 87.9% vs 93.5% (p = 0.12), 41.2% vs 81.1% (p < 0.001), 18.0% vs 51.1% (p = 0.034). N stage was an independent factor for PFS in patients with non-neck dissection (NND) and patients were divided into two groups: low-risk, N0; and high-risk, N1/2. The 5-year PFS rate of the low-risk, and high-risk patients receiving non-PORT and PORT was 77.9% vs 94.3% (p = 0.0019), 21.4% vs 71.3% (p = 0.015). Compared with EBV DNA = 0, the 5-year PFS rate of patients with EBV DNA > 0 was 19.9% vs 91.3% (p < 0.001). In patients with EBV DNA = 0, the 5-year PFS rate of patients with or without PORT was 95.1% vs 92.3% (p = 0.082); while in patients with EBV DNA > 0, the 5-year PFS rate was 37% vs 9.2% (p = 0.0056).

CONCLUSIONS

In patients with ND, PLNs < 3&size < 3 cm patients did not benefit from PORT. Detectable EBV DNA after surgery was a negative prognostic factor.

Intraoral salivary lymphoepithelial carcinoma: clinicopathologic and immunophenotypic characterization of 3 cases indicates elevated programmed death-ligand 1 expression

OBJECTIVE

Intraoral salivary lymphoepithelial carcinoma (ISLEC) is a rare malignancy with programmed death-ligand 1 (PD-L1) expression levels that have been greatly understudied. We examined the clinicopathologic and immunophenotypic characteristics, including PD-L1 levels, of 3 cases of ISLEC.

STUDY DESIGN

We searched the archives of 2 oral and maxillofacial pathology laboratories for specimens diagnosed as ISLEC between 1985 and 2022. We collected patient demographic and clinical data. Immunostaining for AE1/AE3, CK7, CD3, CD20, p16, p53, Ki67, and PD-L1 (SP263), as well as Epstein-Barr virus-encoded small RNAs (EBER) in situ hybridization (ISH) were performed.

RESULTS

All 3 cases affected males aged 42 to 84 years (median = 61y) and involved the floor of the mouth, soft palate/uvula, and tongue. The lesions showed diffuse infiltration by non-keratinizing sheets and islands of undifferentiated carcinoma cells with associated dense lymphoplasmacytic inflammation. Immunohistochemically, all tumors showed AE1/AE3 positivity, selective p53 staining, and negativity for CK7 and p16. Ki67 highlighted 20%-80% of lesional cells. The inflammatory infiltrate comprised a mixed population of T and B lymphocytes. EBER ISH was positive in one case. All ISLECs displayed membranous, focal-to-diffuse, PD-L1 staining with tumor proportion score > 95% in two and 40-50% in the third case.

CONCLUSIONS

The clinicopathologic and immunophenotypic characteristics of the cases we examined highlight the rarity of ISLEC and indicate overall high PD-L1 levels in this type of malignancy, rendering patients with ISLEC potential candidates for targeted α-PD-1/PD-L1 immunotherapy.

Clinical characteristics, prognostic factors, and treatment modalities for head and neck lymphoepithelioma-like carcinoma: A real-world study from southern China

BACKGROUND

We aimed to elucidate the clinical characteristics, prognostic factors and optimal treatment modalities of head and neck lymphoepithelioma-like carcinoma (HNLELC).

METHODS

Consecutive patients newly-diagnosed with non-metastatic HNLELC between December 2001 and March 2021 treated with curative intent were retrospectively reviewed.

RESULTS

A total of 288 patients were included, of whom 87 (30.2%) underwent radical surgery alone, 43 (14.9%) underwent definitive radiotherapy with or without concurrent chemotherapy, and 158 (54.9%) underwent surgery followed by postoperative radiotherapy (SRT). Epstein-Barr virus-encoded small RNA (EBER) was positive in 94.8% (239/252) of patients. Cervical node infiltration was seen in 52.8% (152/288) of patients. No significant difference was found in nodal metastasis rate between T1-2 and T3-4 classifications (49.5% vs. 56.5%, p = 0.308). The 3-year overall survival (OS), disease-free survival, locoregional relapse-free survival, and distant metastasis-free survival rates were 89.4%, 78.7%, 89.2%, and 87.7%, respectively. Compared to SRT, surgery alone associated with significant reduced 3-year local (92.8% vs. 96.5%, p = 0.012) and regional relapse-free survival rates (89.3% vs. 96.8%, p = 0.002). Definitive radiotherapy and SRT demonstrated comparable results in all 3-year survival outcomes (all p＞0.05). Multivariate analysis found EBER status was an independent favorable prognostic factor for OS (HR = 0.356, 95% CI: 0.144-0.882, p = 0.026).

CONCLUSION

HNLELC was observed to associate with EBV infection and cervical nodal infiltration. Definitive radiotherapy achieved similar survival outcomes compared to SRT, and may serve as a good substitute for patients unfit or unwilling to undergo surgery.

Extranodal Follicular Dendritic Cell Sarcoma of the Head and Neck Region: A Clinicopathological Study of 7 Cases

Background. Follicular dendritic cell (FDC) sarcoma is a rare neoplasm arising from follicular dendritic cells (FDCs). It can be nodal or extranodal. Histological diagnosis of extranodal FDC sarcoma in the head and neck region is challenging and a significant percentage are misdiagnosed. Objectives. To report clinicopathological features of head and neck extranodal FDC sarcoma cases and discuss differential diagnoses. Methods. Seven head and neck extranodal FDC sarcomas were retrieved and clinicopathological features were noted. Results. Two tumors each involved parapharyngeal space and tonsil while remaining cases involved the parotid, soft tissue of neck and oropharynx. Age range was 12 to 79 years (mean and median age were 40 and 44 years respectively) and there was a male predilection (6 males: 1 female). All showed spindle to ovoid cells arranged in fascicles, whorls and/or storiform pattern. Mitoses ranged from 3 to 20/mm2. All tumors expressed CD21 and CD23. Two patients died of their disease at 9 and 16 months. Both had tumors larger than 5 cm with ≥10 mitoses/mm2. Three patients were alive at 12, 44 and 184 months. Conclusions. There was a distinct male predominance in our cohort. FDC sarcoma should be included in the differential diagnosis of spindle cell extranodal neoplasms in the head and neck with a whorled growth pattern and intratumoral lymphocytes. Head and neck region tumors show similar clinicopathologic characteristics as their counterparts at other locations with potential for aggressive behavior especially in tumors greater than 5 cm in size and with high mitotic rates.

Epstein-Barr Virus-Associated Lymphoepithelial Carcinoma Arising in a Salivary Sebaceous Lymphadenoma

BACKGROUND

Lymphadenomas are rare benign tumors of the major salivary glands that are further classified as sebaceous and non-sebaceous. No association with viruses has been reported so far. Little is known about the mechanisms that allow lymphadenomas to undergo malignant transformation. Among these rare instances, there has never been a malignant transformation to Epstein-Barr virus (EBV)-associated lymphoepithelial carcinoma.

METHODS

Clinical data of the reported case were retrieved from the patient's electronic medical record. Hematoxylin & eosin-stained slides, immunohistochemical tests, and in situ hybridization performed for routine diagnostic purposes were reviewed.

RESULTS

We report a salivary gland sebaceous lymphadenoma in which the luminal components were mostly replaced by malignant epithelial cells with markedly atypical nuclear features. Presence of EBV was demonstrated in all components by EBER. The morphological and immunohistochemical findings were consistent with a lymphoepithelial carcinoma arising from a sebaceous lymphadenoma.

CONCLUSION

We report the first case of an Epstein-Barr virus-associated lymphoepithelial carcinoma arising from a sebaceous lymphadenoma.

A Case of Primary Lymphoepithelioma-Like Carcinoma of the Bladder With Review

Lymphoepithelioma-like carcinoma (LELC) was characterized by epithelial neoplastic cells developing in solid or incohesive sheets mixed with a noticeable lymphoid infiltration. Lymphoepithelioma-like carcinoma of the bladder (LELCB), which was first described by Zukerberg, is a rare variant of LELC. Here we reported a new case of LELCB occurring in a 70-year-old woman presenting with hematuria. Computed tomography (CT) and cystoscopy revealed a tumor on the left upper wall of the bladder. A partial cystectomy was finally performed. Pathological and immunohistochemical analysis revealed LELCB. After receiving systemic adjuvant chemotherapy, the patient conducted a 25-month follow-up without experiencing a recurrence.

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.

Histopathological Aspects of the Prognostic Factors for Salivary Gland Cancers

Salivary gland cancers (SGCs) are diagnosed using histopathological examination, which significantly contributes to their progression, including lymph node/distant metastasis or local recurrence. In the current World Health Organization (WHO) Classification of Head and Neck Tumors: Salivary Glands (5th edition), malignant and benign epithelial tumors are classified into 21 and 15 tumor types, respectively. All malignant tumors have the potential for lymph node/distant metastasis or local recurrence. In particular, mucoepidermoid carcinoma (MEC), adenoid cystic carcinoma (AdCC), salivary duct carcinoma, salivary carcinoma, not otherwise specified (NOS, formerly known as adenocarcinoma, NOS), myoepithelial carcinoma, epithelial-myoepithelial carcinoma, and carcinoma ex pleomorphic adenoma (PA) are relatively prevalent. High-grade transformation is an important aspect of tumor progression in SGCs. MEC, AdCC, salivary carcinoma, and NOS have a distinct grading system; however, a universal histological grading system for SGCs has not yet been recommended. Conversely, PA is considered benign; nonetheless, it should be cautiously treated to avoid the development of metastasizing/recurrent PA. The aim of this review is to describe the current histopathological aspects of the prognostic factors for SGCs and discuss the genes or molecules used as diagnostic tools that might have treatment target potential in the future.

Lymphoepithelial carcinoma of the head and neck: a SEER analysis of prognostic factors for survival

OBJECTIVE

To explore the epidemiological characteristics of patients with lymphoepithelial carcinoma (LEC) of the head and neck and the prognostic factors.

METHODS

We conducted a retrospective cohort study of cases of head and neck LEC retrieved from the Surveillance, Epidemiology and End Results database. Kaplan-Meier survival analysis and the log-rank test were employed to assess overall survival (OS) and cancer-specific survival (CSS). Univariate and multivariate analyses were used to construct Cox regression models. We established nomograms to predict OS and CSS among patients with nasopharyngeal LEC, who were divided into high- and low-risk groups based on the OS nomograms to compare the effects of treatment using the restricted mean survival time (RMST).

RESULTS

The 5-year OS and CSS rates of the cohort were 70.8% and 74.8%, respectively. Advanced age, unmarried status, black race, distant metastasis, and the absence of surgical treatment were significantly associated with decreased survival rates. RMST did not differ between the combined treatment (radiotherapy and chemotherapy) and radiotherapy monotherapy groups, but chemotherapy alone displayed poor efficacy.

CONCLUSIONS

Head and neck LEC is associated with a favorable prognosis. Radiotherapy plays a significant role in managing patients with nasopharyngeal LEC, which is influenced by multiple prognostic factors.

Lymphoepithelial Subtype of Oral Squamous Cell Carcinoma: Report of an EBV-Negative Case and Literature Review

Lymphoepithelial carcinoma (LEC) of the oral mucosa is a rare histopathologic subtype of squamous cell carcinoma (SCC), which shares morphologic similarities with nasopharyngeal carcinoma (NPC), non-keratinizing undifferentiated subtype. The admixture of neoplastic epithelial tumor cells and a dense lymphoplasmacytic infiltrate makes microscopic diagnosis challenging. LEC etiopathogenesis has been variably associated with Epstein–Barr virus (EBV) infection, depending on the specific anatomic location and racial predilection, with a higher incidence in endemic populations. Although described in several subsites of the head and neck region, including the major salivary glands, the oral mucosa is considered an infrequent location for LEC development, deriving either from minor salivary glands (MSGs) or the surface epithelium. Herein, we report a rare case of an EBV-negative LEC arising from the oral surface epithelium, presenting as gingival swelling, and review the pertinent English-language literature, which revealed only 26 previously reported oral LECs. Our case is only the fourth oral LEC originating from the surface epithelium and the first one to affect the gingiva.

Lymphoepithelial carcinoma of the parotid gland: Clinicopathological analysis of 146 cases from a single institute

BACKGROUND

Parotid lymphoepithelial carcinoma (LEC) is a rare malignant tumor. The purpose of this study was to investigate the clinicopathological features of parotid LEC.

METHODS

All patients clinicopathological information diagnosed parotid LEC from 2005 to 2017 were analyzed.

RESULTS

A total of 146 cases of parotid LECs were identified. Of these, 126 (86.3%) were primary and 20 (13.7%) were secondary LECs. Patients with secondary LEC tended to have tumors with earlier TNM staging than those with primary (p = 0.031). The tumor cells in 87 (94.6%, 87/92) cases tested positive for Epstein-Barr virus (EBV). Cervical node metastases were present at diagnosis in 46 (31.5%) cases. Overall survival at 5 and 10 years was 97.0% and 90.8%, respectively. Older age was an adverse prognostic indicator for overall survival (p < 0.001).

CONCLUSIONS

Parotid LEC is associated with EBV and an increased rate of cervical node metastases. However, most patients, especially younger ones, have a good prognosis.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Hypopharynx, Larynx, Trachea and Parapharyngeal Space

In this article, we review the chapter on tumors of the larynx, hypopharynx, trachea and parapharyngeal space in the new edition of the WHO book, focusing on the new developments in comparison to the previous edition. Squamous cell carcinoma (SCC) and its variants are by far the most common malignancies at these locations, with very limited new insights. The most important is the introduction of new targeted treatment-checkpoint inhibitors, with a new task for pathologists, who may help to predict the response to treatment by analyzing the expression of targeted proteins in biopsy samples. Precancerous lesions remain a controversial topic and, similarly to other organs, it is acceptable to use the terms "dysplasia" or "squamous intraepithelial lesion" (SIL), but there is a slight difference between low-grade dysplasia and low-grade SIL: in the former, mild atypia must be present, while the latter also includes hyperplastic epithelium without atypia. Two approaches have been proposed: a two-tiered system with low- and high-grade dysplasia/SIL and a three-tiered system with an additional category, carcinoma in situ. We are still searching for reliable diagnostic markers to surpass the subjectivity in biopsy diagnosis, with a few potential candidate markers on the horizon, e.g., stem cell markers. Other tumors are rare at these locations, e.g., hematolymphoid, neuroendocrine and salivary gland neoplasms, and are no longer included in Chapter 3. They must be diagnosed according to criteria described in specific chapters. The same holds true for soft tissue tumors, with the exception of cartilaginous neoplasms, which are still included in Chapter 3.

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

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

Expression Profiles and Prognostic Value of Multiple Inhibitory Checkpoints in Head and Neck Lymphoepithelioma-Like Carcinoma

Background

Inhibitory checkpoints are promising antitumor targets and predictive biomarkers in a variety of cancers. We aimed to identify the expression levels and prognostic value of multiple inhibitory checkpoints supported by preclinical and clinical evidence in head and neck lymphoepithelioma-like carcinoma (HNLELC).

Methods

The expression of seven inhibitory checkpoints were evaluated in the tumor nest (TN) and tumor stroma (TS) of 102 HNLELC specimens using immunohistochemistry and digital pathology, and an inhibitory checkpoint-based signature (ICS) was subsequently constructed using the LASSO Cox regression model.

Results

PD-L1, B7H3, and IDO-1 were mostly expressed in the TN, with median H-score of TN vs TS: 63.6 vs 14.6; 8.1 vs 1.0; 61.5 vs 34.7 (all P &lt; 0.001), whereas PD-1, TIM-3, LAG-3, and VISTA were mainly observed in the TS, with median H-score of TN vs TS: 0.2 vs 12.4, 3.4 vs 7.1, 6.2 vs 11.9, 16.4 vs 47.2 (all P &lt; 0.001), respectively. The most common simultaneously expressed combinations consisted of PD-L1 + B7H3 + IDO-1 + TIM-3 + LAG-3 + VISTA and B7H3 + IDO-1 + TIM-3 + LAG-3 in the TN (both occurring in 8.8% of patients) and PD-L1 + B7H3 + IDO-1 in the TS (4.9%). In addition, high-ICS patients had shorter 5-year disease-free (40.6% vs 81.7%; P &lt; 0.001), regional recurrence-free (63.5% vs 88.2%; P = 0.003), and overall survival (73.5% vs 92.9%; P = 0.006) than low-ICS patients. Multivariate analysis revealed that ICS represented an independent predictor, which could significantly complement the predictive performance of TNM stage for 3-year (AUC 0.724 vs 0.619, P = 0.014), 5-year (AUC 0.727 vs 0.640, P = 0.056), and 10-year disease-free survival (AUC 0.815 vs 0.709, P = 0.023).

Conclusions

The expression of inhibitory checkpoints and ICS classifier may increase the prognostic value of the TNM staging system and guide the rational design of personalized inhibitory checkpoint blockade therapy in HNLELC.

Undifferentiated and dedifferentiated head and neck carcinomas

Undifferentiated carcinomas arising at salivary gland and head and neck mucosal sites may originate either de novo or through a process of dedifferentiation of a differentiated carcinoma. While in the latter group the diagnosis is largely dependent on the identification of the differentiated component or recognition of a specific genotype, the classification of undifferentiated carcinomas that lack a differentiated component is mainly based on the identification of specific genetic drivers, like for example the NUTM1 fusions in NUT carcinoma. A further category is represented by virus associated carcinomas (mainly HPV and EBV), that frequently displays an undifferentiated morphology. Overall, these tumors often represent a diagnostic challenge, especially in small biopsies. This review summarizes and discuss the diagnostic approach to the main head and neck carcinoma types that frequently or occasionally display an undifferentiated appearance, with a focus on salivary gland, oropharyngeal, nasopharyngeal and sinonasal subsites.

Lymphoepithelial Carcinoma of the Palatine Tonsil

Lymphoepithelial carcinoma is an undifferentiated carcinoma with nonneoplastic lymphoplasmacytic infiltrate, mostly located in the nasopharynx, while it is extremely rare in the oropharynx. We present a rare case of lymphoepithelial carcinoma arising from palatine tonsil. A 81-year old male patient complained of dysphagia, hypersalivation and bloody sputum. Clinical examination revealed hypertrophy of the right palatine tonsil and ipsilateral cervical lymphadenopathy. Biopsy and histopathological analysis confirmed the diagnosis of lymphoepithelial carcinoma. Multi-slice computed tomography showed a 33x31x38 mm heterodense mass in the region of the right palatine tonsil, and 37x30 mm and 21x20 mm lymph nodes on the right side of the neck. The patient was reffered to an oncology council, which suggested radiotherapy and concurrent chemotherapy. Although rare in clinical practice, lymphoepithelial carcinoma should be considered in cases of tonsil cancer.

CD4-positive lymphoepithelial-like carcinoma: Report of unusual case

We are reporting an unusual case of lymphoepithelial-like carcinoma (LELC) in an 8-year-old female patient where the tumor cells showed unusual CD4 expression. The lesion was found in the left submandibular neck region, in the vicinity of the submandibular gland. The salivary gland was not infiltrated by the tumor, and the tumor exhibited a classic LELC with single and clusters of tumor cells surrounded by many hematolymphoid cells. The tumor cells revealed strong positivity for Epstein-Bar virus as confirmed by the EBER: Epstein-Barr Virus in situ hybridization (EBER-ISH) method of staining. Interestingly, the tumor cells expressed membranous immunostaining for the T-helper lymphocyte antibody (CD4) in addition to pan-cytokeratin. A brief discussion about this unusual finding is offered. The patient was treated as a case of Epstein-Bar virus-associated nasopharyngeal carcinoma with excellent response.

Lymphoepithelioma-like carcinoma of uterine cervix: Preoperative diagnosis and course in three cases

Lymphoepithelioma-like carcinoma of the uterine cervix is a rare variant of squamous cell carcinoma. Herein, we describe three cases of lymphoepithelioma-like carcinoma of the uterine cervix and review relevant literature. All three patients initially presented with postmenopausal bleeding. Gross appearances were endophytic with ulcerated mucosa in case 1, exophytic with polypoid morphology in case 2, and unremarkable even using colposcopy and hysteroscopy in case 3. Magnetic resonance imaging demonstrated well-demarcated cervical masses with high-intermediate intensity on T2-weighted images and high intensity on diffusion-weighted images in all three cases. In case 3, biopsy referring to local information from magnetic resonance images was required for preoperative diagnosis. We reviewed the literature of 59 lymphoepithelioma-like carcinoma cases in 19 papers published between 2001 and 2020. Preoperative diagnosis of lymphoepithelioma-like carcinoma is sometimes challenging, although magnetic resonance imaging findings may help determine the location of the tumor and obtain a successful biopsy.

Lymphoepithelial carcinoma of larynx and hypopharynx: a systematic review and pooled analysis

PURPOSE

To define the oncologic outcomes and the prognostic factors of laryngeal and hypopharyngeal lymphoepithelial carcinoma (LEC).

METHODS

A systematic review and individual patient data analysis were performed according to the PRISMA guidelines. A total of 41 patients (males: 37; mean age: 63.1, standard deviation: 10.0) were included.

RESULTS

The median follow-up time was 36.0 months (interquartile range, IQR: 11.5-73.5), while the median overall survival (OS) time was 96 months (IQR: 39.0-120.0). Estimated disease-specific survival (DSS) rates (95% Confidence Interval, CI; number still at risk) at 1, 3, and 5 years were 94.4% (79.5-98.6; 31), 82.7% (62.7-92.5; 21), and 78.1% (56.8-89.7; 13), respectively. Estimated disease-free survival (DFS) rates (95% CI; number still at risk) at 1, 3, and 5 years were 92.1% (77.4-97.4; 31), 74.9% (55.6-86.8; 21), and 66.6% (46.1-80.8; 13), respectively. Patients undergoing primary surgery had a reduced chance of death from cancer than patients receiving primary radiotherapy (5-year DSS 85.6 vs. 56.2%; p = 0.04), while EBV positivity tend to be a negative prognostic factor (5-year DSS 100 vs. 66.7%; p = 0.05).

CONCLUSIONS

Laryngeal and hypopharyngeal LEC is a rare disease with favorable survival. Further prospective multicenter studies are needed to make a reliable statement on prognosis and outcome, stratifying patients for different therapy regimens and tumor stages.

Tumour infiltrating lymphocytes in oropharyngeal carcinoma: prognostic value and evaluation of a standardised method

Tumour infiltrating lymphocytes (TILs) have been described as a biomarker for the host immune response against the tumour with prognostic properties. The International Immuno-Oncology Biomarkers Working Group (IBWG) proposed a standardised method for quantifying TILs in solid tumours to improve consistent and reproducible scoring. In this study, the methodology was tested in a retrospective population of oropharyngeal squamous cell carcinoma (OPSCC). TIL quantification was performed on 92 OPSCC samples (2004-2013) by four independent observers as described by the IBWG. Interobserver variability was assessed and results were correlated with clinicopathological variables and survival. TIL evaluation turned out to be challenging in OPSCC due to heterogeneity of TILs distribution, presence of pre-existing lymphoid tissue, surface ulceration or erosion and insufficient amount of intertumoural stroma in biopsies. Nonetheless, interobserver variability proved to be good to excellent. High stromal TILs (TILstr) and intratumoural TILs (TILtum) were both correlated to favourable overall survival and multivariate analysis showed TILstr to be the sole independent prognostic factor in OPSCC. The IBWG-proposed TIL quantification method is feasible and reproducible in OPSCC and provides valuable prognostic information regarding clinicopathological characteristics and overall survival. The use of this standardised methodology may facilitate implementation of TILs scoring as a prognostic biomarker in OPSCC.

Interplay between Epstein-Barr virus infection and environmental xenobiotic exposure in cancer

Epstein-Barr virus (EBV) is a herpesvirus associated with lymphoid and epithelial malignancies. Both B cells and epithelial cells are susceptible and permissive to EBV infection. However, considering that 90% of the human population is persistently EBV-infected, with a minority of them developing cancer, additional factors are necessary for tumor development. Xenobiotics such as tobacco smoke (TS) components, pollutants, pesticides, and food chemicals have been suggested as cofactors involved in EBV-associated cancers. In this review, the suggested mechanisms by which xenobiotics cooperate with EBV for carcinogenesis are discussed. Additionally, a model is proposed in which xenobiotics, which promote oxidative stress (OS) and DNA damage, regulate EBV replication, promoting either the maintenance of viral genomes or lytic activation, ultimately leading to cancer. Interactions between EBV and xenobiotics represent an opportunity to identify mechanisms by which this virus is involved in carcinogenesis and may, in turn, suggest both prevention and control strategies for EBV-associated cancers.

A Case Report of Tongue Lymphoepithelial Carcinoma with a Histological Diagnostic Dilemma

Most head and neck lymphoepithelial carcinomas (LECs) arise in the nasopharynx and harbor Epstein–Barr virus (EBV). LEC is also a rare subtype of the oral squamous cell carcinoma (SCC). Morphologically, LEC is defined as resembling non-keratinizing nasopharyngeal carcinoma, undifferentiated subtype. The histological features and pathogenesis of oral LEC are not established. We describe a case of tongue LEC with histopathological diagnostic difficulties. A 72-year-old Japanese female presented with a whitish change on her left-side tongue. The diagnosis was atypical epithelium; neoplastic change could not be ruled out by a biopsy. Although the lesion was monitored at our hospital per her request, invasive carcinoma was detected 11 months later. Microscopically, conventional SCC was observed with the characteristic features as LEC confined to the deep part of the lesion. We briefly discuss this unusual histological finding and make a novel proposal for distinguishing oral LEC from LECs in other regions based on these histological findings.

The evolution of the nasopharyngeal carcinoma staging system over a 10-year period: implications for future revisions

BACKGROUND

The classification criteria and staging groups for nasopharyngeal carcinoma described in the Union for International Cancer Control/American Joint Committee on Cancer (UICC/AJCC) staging system have been revised over time. This study assessed the proportion of patients whose staging and treatment strategy have changed due to revisions of the UICC/AJCC staging system over the past 10 years (ie, from the sixth edition to the eighth edition), to provide information for further refinement.

METHODS

We retrospectively reviewed 1901 patients with non-metastatic nasopharyngeal carcinoma treated in our cancer center between November 2009 and June 2012. The Akaike information criterion and Harrell concordance index were applied to evaluate the performance of the staging system.

RESULTS

In total, 25 (1.3%) of the 1901 patients who were staged as T2a according to the sixth edition system were downgraded to T1 in the eighth edition; 430 (22.6%) staged as N0 in the sixth edition were upgraded to N1 in the eighth edition; 106 (5.6%) staged as N1/2 in the sixth edition were upgraded to N3 in the eighth edition. In addition, 51 (2.7%) and 25 (1.3%) of the study population were upstaged from stage I to stage II and stage II to stage IVa, respectively; 10 (0.5%) was downgraded from stage II to stage I. The survival curves of adjacent N categories and staging groups defined by eighth classification system were well-separated. However, there was no significant difference in the locoregional failure-free survival (P = 0.730) and disease-free survival (P = 0.690) rates between the T2 and T3 categories in the eighth edition classification system.

CONCLUSIONS

Modifications to the tumor-node-metastasis staging system over the past 10 years have resulted in N classification changes in numerous cases. Although the eighth edition tumor-node-metastasis staging system better predicts survival outcomes, the T classification could be simplified in future revisions.

Checkpoint Inhibition in the Treatment of Unresectable, Advanced Lymphoepithelioma-like Hepatocellular Carcinoma

Lymphoepithelioma-like hepatocellular carcinoma (LEL-HCC) is a very rare neoplasm, with distinct epidemiologic, morphologic and clinical characteristics. Molecular mechanistic insight into the pathogenesis of this carcinoma suggests a pivotal role for the host immune system in the proliferation and progression of this tumor. However, while detailed genomic profiling of these hepatic tumors have revealed an intra-tumoral inflammatory mutational signature that may predispose to immune checkpoint inhibitor efficacy, no published report has described their use in this tumor type. Unfortunately, with near 100 cases of LEL-HCC reported in the literature to date and the majority of cases confined to localized and resectable disease, current evidence-based practices in the unresectable setting are lacking, with unknown benefit of chemotherapy or immunotherapy. We report on the case of a 68 year-old man with unresectable, advanced LEL-HCC who had evidence of disease stability after starting on the immune checkpoint inhibitor nivolumab. His disease response persisted off therapy for over a year and was potentially augmented by radiotherapy at the site of local progression. For this extremely rare tumor subtype, this case highlights the potential efficacy and safety of immune checkpoint blockade in LEL-HCC and reinforces the need for more robust, large-scale analysis of patients with these rare tumors to better evaluate treatment strategies and outcomes.

Lymphoepithelial Carcinoma of Salivary Glands

Lymphoepithelial carcinoma of salivary glands (LECSG) is an uncommon neoplasm. This article summarizes the findings of 438 cases in a review of the literature. Concurrent lymphoepithelial lesions may suggest a primary tumor. The tumor shows a nonkeratinizing carcinoma intimately associated with a rich lymphohistiocytic infiltrate, destroying adjacent salivary gland tissue. Irrespective of race or ethnicity, the tumors usually express Epstein-Barr virus, with Epstein-Barr virus encoded small RNA (EBER) and/or latent membrane protein-1 (LMP-1), although a subset does not. There is an overall good prognosis of about 80% at 5 years.

PBK phosphorylates MSL1 to elicit epigenetic modulation of CD276 in nasopharyngeal carcinoma

CD276 (also known as B7-H3, an immune checkpoint molecule) is aberrantly overexpressed in many cancers. However, the upregulation mechanism and in particular, whether oncogenic signaling has a role, is unclear. Here we demonstrate that a pro-oncogenic kinase PBK, the expression of which is associated with immune infiltration in nasopharyngeal carcinoma (NPC), stimulates the expression of CD276 epigenetically. Mechanistically, PBK phosphorylates MSL1 and enhances the interaction between MSL1 and MSL2, MSL3, and KAT8, the components of the MSL complex. As a consequence, PBK promotes the enrichment of MSL complex on CD276 promoter, leading to the increased histone H4 K16 acetylation and the activation of CD276 transcription. In addition, we show that CD276 is highly upregulated and associated with immune infiltrating levels in NPC. Collectively, our findings describe a novel PBK/MSL1/CD276 signaling axis, which may play an important role in immune evasion of NPC and may be targeted for cancer immunotherapy.

Clinicopathological characteristics and prognostic analysis of lymphoepithelial carcinoma of salivary gland: a population-based study

Background

The purpose of this study was to elucidate the clinicopathological characteristics of patients with lymphoepithelial carcinoma of salivary gland (LEC-SG) and determine the factors associated with survival.

Methods

A total of 179 LEC-SG patients from the Surveillance, Epidemiology, and End Results (SEER) database between 1975 to 2016 were included. The clinicopathological characteristics and overall survival of LEC-SG patients were described, and the features affecting prognosis were further determined using Kaplan-Meier Curves and Cox survival analysis.

Results

The median overall survival of LEC-SG patients was 206 months, and the 1-, 5-, 10- and 20-year survival rates were 91.0%, 80.2%, 66.4%, and 37.6%, respectively. The prognoses were significantly associated with age, ethnicity, marital status, tumor invasion, as well as lymph node metastases [P<0.01 for all). Surgical resection could significantly improve the prognosis of this disease (median overall survival (mOS): 219 vs. 68 months, P<0.01]. Postoperative radiotherapy could improve long-term survival and decrease the risk of death among patients who survive exceed 10-year after surgery. The Cox regression analysis showed that old age (>60 years) and lymph node metastases were independently associated with poor survival (P<0.05 for both). Conversely, the use of surgery was an independent favorable prognostic factor [hazard ratio (HR) 0.29, 95% CI: 0.13-0.66].

Conclusions

LEC-SG patients had a favorable prognosis with a mOS of 206 months. Old age, lymph node metastases, the use of surgery were independently associated with survival of LEC-SG patients.

A Unique Case of Primary EBV-Positive, HPV-Negative Nasopharyngeal Carcinoma Located in the Tonsil

Nasopharyngeal carcinomas (NPC) are non-keratinizing squamous cell carcinomas of the nasopharynx associated with Epstein-Barr virus (EBV). When occurring outside of the nasopharynx, they are referred to as lymphoepithelioma-like carcinomas (LELCs) and present the same morphology as NPC. LELC have been described in other head and neck regions such as the salivary glands and the soft palate. LELC can also occur in the oropharynx, are associated with human papillomavirus (HPV) and are typically negative for EBV. We herein present a unique case of a 78-year-old Chinese male with EBV-positive, HPV-negative NPC of the left tonsil. His presenting symptom was a left-sided lymph node. There was no evidence of nasopharyngeal lesion seen on physical examination, PET and MRI. The patient was treated with curative-intent external beam radiotherapy which delivered 70 Gy (Gy) to the gross tumour and lymph nodes, and 56 Gy electively to the ipsilateral neck using a volumetric modulated arc therapy technique. This is the first case of primary tonsil EBV-positive NPC described in the literature.

A Rare Case of Sinonasal Lymphoepithelial Carcinoma Presented With Clinically Stage IV Disease

Sinonasal lymphoepithelial carcinoma (SLEC) is an extremely rare malignancy. We present a case of SLEC in a 77-year-old man who presented with nasal congestion and persistent sinusitis. Imaging revealed a large right nasal mass involving right paranasal sinuses along with bulky bilateral cervical lymphadenopathy. In addition, there was a fluorodeoxyglucose avid L1 vertebral lesion. Biopsy of nasal mass and cervical lymph nodes showed syncytial growth of tumor cells in a lymphoplasmacytic background. Immunohistochemical stains showed positivity for pankeratin, CK5/6, epithelial membrane antigen, p40 (focal), and p63 (focal). An Epstein-Barr virus-encoded RNA by in situ hybridization was strong and diffusely positive. Based on these pathologic findings and considering the location of tumor, diagnosis of SLEC was rendered. L1 vertebral body lesion was clinical and radiologically considered to be a metastasis. Correlation with radiology to determine the exact location of tumor is extremely important for correct diagnosis due to its histopathologic similarities with relatively more common undifferentiated type of nasopharyngeal carcinoma. No standard treatment protocol has been established for this tumor yet. To our knowledge, this is first ever report of SLEC presented with clinical stage IV disease.

Middle Ear and Temporal Bone Nonkeratinizing Squamous Cell Carcinomas With DEK-AFF2 Fusion: An Emerging Entity

Primary squamous cell carcinomas (SCCs) of the middle ear and temporal bone are rare and usually keratinizing by morphology. Nonkeratinizing, basaloid SCCs arising in this area are exceedingly rare, and, due to the anatomic proximity to the skull base, nasopharynx, and nasal sinuses, the differential diagnosis is broad. Most tumors with squamous differentiation arising in these subsites are either viral-induced (human papillomavirus/Epstein-Barr virus) or rarely may have specific molecular alterations (BRD4-NUT, EWSR1-FLI translocations). Occasional tumors are negative for these findings, and their pathogenesis is unknown. A recently discovered DEK-AFF2 fusion was clinically detected in a series of 2 cases known to the authors. This fusion has been previously reported in the literature in a patient with a base of skull tumor who was an exceptional responder to programmed cell death protein 1 inhibitor therapy. We examine here the histomorphologic and molecular findings of 2 additional cases of an emerging entity. Two male patients were identified. Each had a primary middle ear/temporal bone mass with locally advanced disease. The histology was reviewed, and immunohistochemistry was performed. RNA-based next-generation sequencing was performed for clinical detection of diagnostic or actionable fusions. Both patients had basaloid/nonkeratinizing tumors on biopsy. They were positive for markers of squamous differentiation (HMWK, CK5, and p40). By RNA sequencing, they demonstrated the presence of a DEK-AFF2 fusion and were negative for EWSR1 and NUT translocations. The DEK-AFF2 fusion may define a novel diagnostic category of middle ear and temporal bone nonkeratinizing/basaloid SCCs. This fusion also may represent a potential avenue for immunotherapy in these patients. Further studies are needed to fully explore whether this fusion defines a location-specific clinicopathologic entity.

Clinicopathological Characteristics and Prognosis of Nasopharyngeal Lymphoepithelial Carcinoma: A Population-Based Retrospective Study

Background

The aim of this study was to establish a predictive model for prognostic factors and overall survival (OS) in nasopharyngeal lymphoepithelial carcinoma (NLEC) patients.

Material/Methods

The data of 538 NLEC patients diagnosed between 1988 and 2015 were extracted from the Surveillance, Epidemiology, and End Results database. Patients who were diagnosed from 1988 to 1999 were included in the validation cohort, and those diagnosed from 2000 to 2015 in the primary cohort. Least absolute shrinkage and selection operator and multivariate Cox regression analyses were performed. The discrimination and calibration capabilities of the predictive models were evaluated using the receiver operating characteristic (ROC) curve and calibration plot, respectively.

Results

Radiotherapy (P<0.0001), early-stage cancer based on the American Joint Committee on Cancer (AJCC) staging system (P<0.0001), younger age (P=0.0005) were associated with better OS rates. In the primary cohort, the areas under the ROC curves (AUC) of the nomogram for predicting 1-, 10-, and 15-year OS were 0.749, 0.754, and 0.81, respectively. Meanwhile, in the validation cohort, the AUC of the nomogram for predicting 1-, 10-, and 15-year OS were 0.692, 0.692, and 0.682, respectively. Furthermore, the calibration plot exhibited optimal agreements between the nomogram-predicted and actual 1-, 10-, and 15-year OS in both cohorts. The 1-, 10-, and 15-year OS rates were 93.6%, 62.7%, and 49.9%, respectively.

Conclusions

Age, early-stage cancer based on the AJCC staging system, radiotherapy, and gender can be used to predict OS in nasopharyngeal lymphoepithelial carcinoma patients.

Lymphoepithelial Carcinoma of Salivary Gland EBV-association in Endemic versus Non-Endemic Patients: A Report of 16 Cases

Lymphoepithelial carcinoma of salivary glands (LECSG) are rare neoplasms, reported in endemic populations (southeastern Chinese) with a strong Epstein-Barr virus (EBV) association. A retrospective series comparing EBV status within an ethnically diverse population (endemic vs. non-endemic patients) has not been reported. Sixteen LECSG were equally distributed between males (n = 8) and females (n = 8) with a median age of 54 years (range 18 to 85 years) at initial diagnosis. Ten patients were white, 4 Asian, and 2 black. The patients typically presented with swelling or mass for an average of 11.6 months. Tumors affected only major salivary glands: parotid (n = 13); submandibular (n = 3). Tumors were an average of 2.9 cm (range 1.5 to 5.8 cm). Nine of 16 (56%) patients had cervical lymph node metastases at presentation. No patients had nasopharyngeal or oropharyngeal tumors. Microscopically, the tumors were widely infiltrative, characterized by large polygonal to spindled cells arranged in a syncytial, lattice-like network in a background of lymphoplasmacytic cells. The neoplastic cells showed an open-vesicular nuclear chromatin to a more basaloid-morphology, the latter showing hyperchromatic nuclei and less cytoplasm, while nearly all of the cases had associated lymphoepithelial lesions/sialadenitis. By in situ hybridization, 8 of 16 cases had a strong, diffuse EBER expression (4 of 4 Asians; 4 of 12 non-Asians), while with immunohistochemistry all cases tested were pan-cytokeratin, CK5/6 and p63 reactive; none of the cases tested were p16 reactive. All patients were managed with wide or radical excision, 4 with concurrent chemoradiation, and 6 with radiation alone. Distant metastasis (lung, brain, and bone) developed in 2 patients. Overall follow-up (mean 3.8 years) revealed 12 patients alive and 2 dead, none with evidence of disease (mean 4.3 years); one white male alive with disease at 1.9 years, and one Asian female dead of disease at 4.2 years; both of these latter patients had Group IV stage disease. High stage (Group IV) patients had a shorter mean survival than lower stage patients: 3.1 versus 4.8 years, respectively. In conclusion, LECSG are uncommon primary neoplasms. Concurrent lymphoepithelial lesions may help suggest a primary tumor. The tumors, irrespective of race or ethnicity, may express EBER. There is an overall good survival, perhaps better for EBV-negative patients and for those with lower stage disease.

The evolution of nasopharyngeal carcinoma staging

The prevalence of nasopharyngeal carcinoma is characterized by an unbalanced distribution: the disease is particularly prevalent in East and Southeast Asia. In this article, we review the evolution of the International Union Against Cancer/American Joint Committee on Cancer staging system for nasopharyngeal carcinoma. With the increasing using of newer imaging methods, more advanced radiotherapy techniques and systemic chemotherapy, we also discuss newer clinical features that might affect staging. Finally, we propose the future direction of staging and potential prognostic factors that have a major influence on the treatment outcomes of this disease.

Epstein-Barr Virus-Associated With Lymphoepithelial Carcinoma: A Rare Tumor of the Larynx

Lymphoepithelial carcinoma of the larynx is a rare tumor, as this histological entity is mostly diagnosed in nasopharynx. However, it may be present in other non-nasopharyngeal sites and it is extremely rare in the larynx. The authors present a case of a 59-year-old man who presented to the Otorhinolaryngology-Head and Neck Surgery Department complaining of a long-standing dysphonia, odynophagia, and dysphagia. The clinical examination revealed a laryngeal tumor involving the right epiglottis, right aryepiglottic fold, and ipsilateral false vocal fold. It presented with ispilateral neck lymph node extension. Multiple biopsies of the laryngeal lesion were performed under local anesthesia and the histological examination showed a poorly differentiated squamous cell carcinoma. After discussing the case in a multidisciplinary tumor board, a total laryngectomy with a bilateral neck dissection was performed and the histological specimen showed a lymphoepithelial carcinoma. Although immunostaining with LMP-1 antibody was negative, in situ hybridization for Epstein-Barr virus was positive. He underwent adjuvant chemoradiation. He is now at 9-months follow-up period, with no evidence of disease. Lymphoepithelial carcinoma of the larynx is an extremely rare disease, with an aggressive pattern. Epstein-Barr virus-associated lymphoepithelial carcinoma has been exceptionally reported. A correct diagnosis and close collaboration with pathologist is crucial to achieve the best treatment strategy. We present this case to discuss the clinical and histology findings and the different therapeutic aspects of this uncommon histological subtype carcinoma.

Patterns of EBV-positive cervical lymph node involvement in head and neck cancer and implications for the management of nasopharyngeal carcinoma T0 classification

OBJECTIVES

Epstein-Barr virus (EBV)-positive cervical lymph node (CLN) metastasis of unknown primary origin is classified as nasopharyngeal carcinoma (NPC) T0 by the American Joint Committee on Cancer staging manual (8th edition). We aimed to investigate the possible primary sites and patterns of EBV-positive CLN metastases and to provide implications for the management of NPC T0 classification.

MATERIALS AND METHODS

We retrospectively reviewed 269 patients with newly diagnosed EBV-positive CLN metastatic disease who underwent EBV detection via EBV-encoded RNA in situ hybridization. Fifteen patients with unknown primary tumors underwent follow-up after initial treatment.

RESULTS

In patients with EBV-positive CLNs, the most common primary sites after the nasopharynx (51.7%) were the salivary gland (24.5%), lung (7.8%), oropharynx (3.3%), nasal cavity/maxillary (3.3%), oral cavity (2.2%), orbit (1.1%), and liver (0.4%). No primary site was found in 15 patients (5.6%). For salivary gland malignancies, level II and I were the most frequently involved regions. Tumors arising from the lung or liver metastasized to the lower neck (level IV, V, and VI) rather than the upper neck. After initial treatment, 2/15 patients with EBV-positive CLNs of unknown primary exhibited primary NPC and oropharyngeal tumor, respectively. Further, even without prophylactic irradiation to the nasopharynx, only one of 13 unknown primary patients developed NPC.

CONCLUSIONS

The origins of EBV-positive CLNs may not be restricted to the nasopharynx alone, and are likely to involve the head and neck or non-head and neck regions. NPC T0 classification should be cautiously assigned to such tumors.

Primary Tonsillar Epithelioid Follicular Dendritic Cell Sarcoma: Report of a Rare Case Mimicking Undifferentiated Carcinoma and a Brief Review of the Literature

We present a 52 years old male with a left tonsillar follicular dendritic cell sarcoma with prominent epithelioid features that on light microscopical examination bore a striking resemblance to a lymphoepithelial or undifferentiated carcinoma. The tumor was immunohistochemically positive for CD21 and CD35 and negative for cytokeratins. Two distinct histopathological features (both present in our case) that may serve as clues to the correct diagnosis on light microscopical examination were formation of ectatic pseudovascular spaces lined by malignant cells and the presence of non-neoplastic multinucleated giant cells. Familiarity with the above-mentioned morphological clues, and awareness that this tumour may occur in anatomical sites outside the lymph node, are essential for accurate diagnosis.

Lymphoepithelial carcinoma of the maxillary sinus: A case report and review of the literature

RATIONALE

Most cases of lymphoepithelial carcinoma (LEC) occur in the nasopharynx, and LEC in the sinonasal tract is extremely rare; thus, the clinical characteristics of sinonasal LEC are not well known.

PATIENT CONCERNS

A 63-year-old Japanese man presented with a three-week history of left cheek pain, nasal obstruction and cheek swelling.

DIAGNOSES

Enhanced CT and MRI revealed a tumor of the left maxillary sinus that invaded the left orbit and hard palate, with multiple swollen left cervical lymph nodes. Open biopsy was performed, and the specimen was diagnosed as LEC.

INTERVENTIONS

Alternating chemoradiotherapy (ALCRT) followed by salvage surgery was performed.

OUTCOMES

Our patient has been disease free for 5 years.

LESSONS

A literature review of the epidemiology, etiology, clinical course and management of sinonasal LEC is highlighted. We believe ALCRT followed by salvage surgery to be a highly optimal treatment for sinonasal LEC from the viewpoint of a balance between quality of life and a high curative effect.

PIK3CA and p53 Mutations by Next Generation Sequencing in Lymphoepithelioma-Like Carcinoma of the Endometrium

Lymphoepithelioma-like carcinoma of the endometrium is a very rare variant of endometrial carcinoma characterized by syncytial nests of pleomorphic epithelial cells and heavy infiltration of the stroma by lymphocytes (in particular CD8 cytotoxic T-lymphocytes) and plasma cells. Until now, only five cases have been characterized in this location. This report describes the clinicopathological and the molecular features of this unusual tumor. In particular, using the next generation sequencing (NGS) technique, we have demonstrated that this tumor could be associated with PIK3CA and p53 gene mutations. These data have not been reported to date and suggest that lymphoepithelioma-like carcinoma of the endometrium shares common molecular features with high grade endometrioid and serous-like endometrial carcinoma which are associated with poor outcome. Nevertheless, in endometrial lymphoepithelioma-like carcinoma, the alterations on cell cycle, apoptosis, and/or senescence secondary to p53 mutations could potentially be counterbalanced by the antitumoral response induced by CD8 cytotoxic T-lymphocytes numerous in these tumors.

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".

Primary lymphoepithelial-like carcinoma of the parotid gland-case presentation

Background/Aim: Primary Lymphoepithelial carcinoma (PLEC) is a rare subtype of salivary gland cancers, which comprises only 0.4% of salivary malignant neoplasms and only a few cases have been presented previously. Case report: A patient with PLEC of the parotid gland, its management and the available literature are presented. A 53-year-old woman with initial lesion of a lump in the region of the right parotid received treatment with antibiotics which did not lead to improvement. MRI was performed that recorded the presence of a tumor in the right parotid gland and the patient subsequently underwent excision biopsy. The histopathological evaluation together with additional immunohistochemical positive staining of EMA+, EGFR+, p63+, CK 5/6+, AE1/AE3+ established the diagnosis of PLEC. A PET-CT scanning has shown nor primary mucosal source neither skin lesion to account for any possible metastatic disease, consequently a course of adjuvant post-operative radiotherapy to the region of the right parotid gland was performed. Conclusions: In the differential diagnosis of a parotid gland lump should be included the possibility of a rare salivary gland neoplasm such as PLEC. Surgical excision and radiotherapy have been proposed for the treatment of early and advanced neoplasm stages. Ages of the patient, stage of the neoplasm as well as type of therapy are significant and individual variables for the prediction of the prognosis.

Lymphoepithelioma-like carcinoma of the uterine cervix: Cytomorphologic features and diagnostic pitfalls by liquid-based cytology

Lymphoepithelioma-like carcinoma (LELC) is a rare variant of cervical squamous cell carcinoma with unclear HPV and EBV association. Due to the accompanying and often obscuring lymphocytic inflammation, malignant cells may be difficult to recognize on cytologic samples and can mimic several more common benign and atypical cervical lesions. In this case report, we describe the cytomorphologic findings of LELC by liquid-based cytology in a 59-year-old Caucasian woman who was positive for high risk HPV but had no visible cervical lesions. We also discuss the differential diagnosis, diagnostic pitfalls, and practical considerations for diagnosis.