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

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.

A Limited Immunohistochemical Panel to Distinguish Basal Cell Carcinoma of Cutaneous Origin From Basaloid Squamous Cell Carcinoma of the Head and Neck

Head and neck carcinomas with basaloid features can be diagnostically challenging. A common diagnostic issue is the distinction between a basaloid squamous cell carcinoma (bSCC) and a basal cell carcinoma (BCC) of cutaneous origin. This is particularly true in small biopsy specimens where classic architectural and histologic features may be difficult to appreciate. A specific diagnosis is essential because of significant differences in clinical outcome and therapeutic management. Ten resection cases of bSCC and BCC of the head and neck were selected based on primary location and the classic morphologic features that characterize these 2 entities. The following immunohistochemical markers were evaluated: epithelial membrane antigen (EMA), Ber-EP4, CD44, Bcl2, androgen receptor, SOX2, and p16. The strongest statistically significant differences in staining patterns were for EMA, p16, and SOX2. EMA was positive in all bSCCs and negative in all BCCs. SOX2 was positive in all bSCCs and in only 3 out of 10 BCCs. Staining was weak and peripheral in the SOX2-positive BCCs. p16 was positive in 8 out of 10 bSCCs and negative in all BCCs. We conclude that bSCC and BCC of the head and neck can be readily distinguished by a limited panel consisting primarily of EMA, and supported by SOX2 and p16.

Small Cell Neuroendocrine Carcinoma: A Rare Nasopharyngeal Malignancy with Aggressive Clinical Course

Primary small cell neuroendocrine carcinoma is uncommon in head and neck region, with occasional cases in nasopharynx. Distinction from other round cell tumors is imperative to ensure optimal patient management. We present a case of a 30-year-old woman who presented with a rapidly growing nasopharyngeal mass.

Usefulness of NKX2.2 Immunohistochemistry for Distinguishing Ewing Sarcoma from Other Sinonasal Small Round Blue Cell Tumors

NKX2.2 is a new immunohistochemical marker that has been reported to be sensitive and specific for Ewing sarcoma (ES). It has not, however, been investigated specifically in the sinonasal small round blue cell tumor (SRBCT) differential diagnosis which includes many tumors specific to that site. It has also not been investigated in the newly recognized "adamantinoma-like" variant of ES. Immunohistochemistry for NKX2.2 was performed on 170 poorly differentiated sinonasal neoplasms: 73 squamous cell carcinomas (67 poorly differentiated, non-keratinizing, or basaloid types and 6 nasopharyngeal carcinomas), 46 olfactory neuroblastomas, 8 sinonasal undifferentiated carcinomas (SNUCs), 6 melanomas, 7 Ewing sarcomas, 6 SMARCB1-deficient carcinomas, 6 teratocarcinosarcomas, 5 alveolar rhabdomyosarcomas, 4 solid adenoid cystic carcinomas, 4 NK/T cell lymphomas, 3 NUT carcinomas, and 2 small cell carcinomas. NKX2.2 was positive in 7 of 7 (100%) Ewing sarcomas, including 3 adamantinoma-like variant (all diffuse, 5 strong and 2 weak). It was also positive in 5 of 6 (83%) teratocarcinosarcomas (strong, but focal), 12 of 46 (26%) olfactory neuroblastomas (diffuse, 2 strong and 10 weak), 4 of 6 melanomas (2 diffuse, 2 focal, all weak), and 1 of 2 small cell carcinomas (diffuse and strong). All squamous cell carcinomas, NUT carcinomas, SMARCB1-deficient carcinomas, SNUCs, solid adenoid cystic carcinomas, NK/T cell lymphomas, and alveolar rhabdomyosarcomas were negative. In the sinonasal SRBCT differential diagnosis, NKX2.2 is a useful and very sensitive marker for Ewing sarcoma, including the treacherous adamantinoma-like variant. At the same time, it is not entirely specific, as it will be positive in a subset of other neuroendocrine/neuroectodermal tumors. As a result, NKX2.2 must be utilized as part of an immunohistochemical panel with other markers, especially cytokeratins, melanoma markers, and CD99.

Sinonasal Tract Alveolar Rhabdomyosarcoma in Adults: A Clinicopathologic and Immunophenotypic Study of Fifty-Two Cases with Emphasis on Epithelial Immunoreactivity

Sinonasal tract (SNT) alveolar rhabdomyosarcoma (ARMS) are frequently misdiagnosed, especially in adults. Fifty-two adult (≥18 years) patients with SNT ARMS were reviewed and characterized by immunohistochemistry and molecular studies. Twenty-six females and 26 males (18-72 years; mean 43.2 years), presented after a short duration (mean 2.6 months) with a large (mean 5.5 cm) destructive nasal cavity mass, involving multiple contiguous paranasal sites (n = 46) and with cervical adenopathy (n = 41). The tumors showed an alveolar, nested to solid growth pattern below an intact, but often involved (n = 9) epithelium with frequent necrosis (n = 37), destructive bone invasion (n = 30), and lymphovascular invasion (n = 25). The neoplastic cells were dyshesive and dilapidated, with crush artifacts. Rhabdoid features (n = 36) and tumor cell multinucleation (n = 28) were common. Mitotic counts were high (mean 17/10 HPFs). The neoplastic cells showed the following immunohistochemical positive findings: desmin (100%), myogenin (100%), MYOD1 (100%), MSA (96%), SMA (52%), CAM5.2 (50%), AE1/AE3 (36%); other positive markers included S100 protein (27%), CD56 (100%), synaptophysin (35%), and chromogranin (13%). Overall, 54% show epithelial marker reactivity. Molecular studies showed FOXO1 translocations (81%) with PCR demonstrating PAX3 in 72.7% tested. Patients presented with high stage (IV 24; III 26) and metastatic disease (lymph nodes n = 41; distant metastases n = 25) (IRSG grouping). Surgery (n = 16), radiation (n = 41) and chemotherapy (n = 45) yielded an overall survival of 36.1 months (mean; range 2.4-286); 18 alive without disease (mean 69.6 months); 7 alive with disease (mean 11.0 months); 1 dead without disease (63.7 months); and 26 dead with disease (mean 18.5 months). SNT ARMS frequently present in adults as a large, destructive midline mass of short symptom duration, with high stage disease. The alveolar to solid pattern of growth of cells with rhabdoid-plasmacytoid features suggests the diagnosis, but epithelial immunohistochemistry markers are present in 54% of cases, leading to misdiagnosis as carcinomas if muscle markers are not also performed. Overall survival of 36.1 months is achieved with multimodality therapy, but 64% have incurable disease (16.9 months). Mixed anatomic site (p = 0.02) was a significant adverse prognostic indicator, while stage (0.06) and tumor size >5 cm (0.06) approached marginal significance.

Small round blue cell tumors of the sinonasal tract: a differential diagnosis approach

One of the most challenging diagnostic categories within tumors of the sinonasal tract is the small round blue cell tumors. Biopsies are usually small and limited, resulting in considerable diagnostic difficulty for practicing surgical pathologists. These tumors share several overlapping histologic and immunophenotypic findings while also showing considerable variation within and between cases. Specific tumor site of origin, imaging findings, and clinical findings must be combined with the histology and pertinent ancillary studies if the correct diagnosis is to be reached. Discrimination between neoplasms is critical as there are significant differences in therapy and overall outcome. It is important to have a well developed differential diagnosis for this category of tumors, where each of the diagnoses is considered, evaluated, and either confirmed or excluded from further consideration. In an undifferentiated tumor, showing a small round blue cell morphology, using the mnemonic 'MR SLEEP' helps to highlight tumors to consider: melanoma, mesenchymal chondrosarcoma, rhabdomyosarcoma, sinonasal undifferentiated carcinoma, squamous cell carcinoma (including NUT carcinoma), small cell osteosarcoma, lymphoma, esthesioneuroblastoma (olfactory neuroblastoma), Ewing sarcoma/primitive neuroectodermal tumor, pituitary adenoma, and plasmacytoma. A panel of pertinent immunohistochemistry studies, histochemistries and/or molecular tests should aid in reaching a diagnosis, especially when taking the pattern and intensity of reactions into consideration.

An Update on Sinonasal Round Cell Undifferentiated Tumors

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

The role of cytology in the era of HPV-related head and neck carcinoma

Enlarged neck lymph nodes are very often subject to fine needle aspiration biopsy to detect metastatic disease in patients with suspected or proven squamous cell carcinoma in head and neck region. Cytology specimens of metastatic carcinoma in such patients are routinely evaluated for human papilloma virus (HPV) to identify patients with HPV-related head and neck squamous cell carcinoma. Different types of cytology specimens including smears, cytospins, cell blocks and aspirated material in the rinse can all be used for different types of HPV testing such as immunohistochemistry for p16, HPV-in situ hybridization, and HPV-Polymerase chain reaction. There is currently no consensus regarding the testing of high-risk HPV in cytology specimens. The establishment of standardized HPV testing of cytology specimens is of utmost importance and is eagerly awaited.

Squamous cell carcinoma variants of the upper aerodigestive tract: a comprehensive review with a focus on genetic alterations

CONTEXT

Squamous cell carcinoma of the upper aerodigestive tract is a heterogenous entity. Although conventional squamous cell carcinomas are easily recognized, the morphologic variants of squamous cell carcinoma can present a diagnostic challenge. Familiarity with these variants is necessary because many are associated with unique risk factors and are characterized by specific molecular alterations (eg, nuclear protein in testis midline carcinomas). Perhaps the most important distinction is in identifying viral-related from nonviral-related carcinomas. The accurate diagnosis of these variants is necessary for prognostic and therapeutic reasons.

OBJECTIVES

To provide a clinicopathologic overview and summary of the molecular alterations of the common squamous cell carcinoma variants, including verrucous, spindle cell, acantholytic, adenosquamous, basaloid, and papillary squamous cell carcinoma, as well as nuclear protein in testis midline carcinoma, and to discuss the distinguishing features of human papillomavirus- and Epstein-Barr virus-related squamous cell carcinomas.

DATA SOURCES

Published peer-reviewed literature.

CONCLUSIONS

Familiarity with squamous cell carcinoma variants is essential for proper diagnosis and to guide appropriate clinical management. Further insight into the molecular alterations underlying those variants may lead to alterations in existing treatment approaches and to evolution of novel treatment modalities.

Utility of p40 in the Differential Diagnosis of Small Round Blue Cell Tumors of the Sinonasal Tract

The sinonasal tract may give rise to a broad range of neoplasms that share a "small round blue cell" tumor (SBRCT) appearance on routine histology, but treatment strategies depend on precise tumor classification. Immunohistochemistry for p63 is often employed in the sinonasal SRBCT differential diagnosis because it is highly sensitive for squamous cell carcinoma (SCC). However, p63 staining may be observed in other tumor types, a potential diagnostic pitfall. P40 is a more squamous-specific isoform of p63, and it may be more useful in distinguishing poorly differentiated SCC from its mimickers in the sinonasal tract. Immunohistochemistry for p40 and p63 was performed on 171 sinonasal neoplasms with SRBCT morphology: 73 SCCs (67 poorly differentiated, non-keratinizing, or basaloid types and 6 nasopharyngeal carcinomas), 46 esthesioneuroblastomas, 11 sinonasal undifferentiated carcinomas (SNUCs), 11 lymphomas, 9 melanomas, 7 alveolar rhabdomyosarcomas, 4 solid adenoid cystic carcinomas, 4 NUT midline carcinomas, 4 primitive neuroectodermal tumors (PNETs), and 2 small cell carcinomas. P40 was positive in 72 of 73 SCCs, and showed a diffuse distribution in all but one positive case. P40 immunoexpression was also observed in 13 of 46 (28 %) esthesioneuroblastomas, 6 of 11 (55 %) SNUCs, 2 of 4 (50 %) adenoid cystic carcinomas, 3 of 4 (75 %) NUT midline carcinomas, 1 of 2 (50 %) small cell carcinomas, and 1 of 4 (25 %) PNETs; in the non-SCC tumors, p40 staining was focal in most cases. P63 was positive in every p40-positive tumor. In addition, a p63+/p40- phenotype was seen 5 of 11 (45 %) lymphomas, 4 of 7 (57 %) alveolar rhabdomyosarcomas, 1 of 4 (25 %) PNETs, and 3 of 46 (7 %) esthesioneuroblastomas. All sinonasal melanomas were negative for both markers. In the sinonasal SRBCT differential diagnosis, both p40 and p63 are highly sensitive for SCC, but p40 is more specific. Notably, p40 is consistently negative in lymphomas and alveolar rhabdomyosarcomas, two tumors that are frequently p63-positive. It must be remembered, however, that even diffuse p40 immunostaining is not entirely specific for the squamous phenotype, and therefore it should be utilized as part of an immunohistochemical panel.

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

Background

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

Objectives

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

Material and Methods

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

Results

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

Conclusions

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

Current diagnostic strategies for undifferentiated tumours of the nasal cavities and paranasal sinuses

Several malignant tumours occurring in the sinonasal tract may present with an undifferentiated morphology. Overall, these lesions pose significant diagnostic difficulties for the surgical pathologist, especially in limited biopsy material, but their correct classification is becoming increasingly important for an appropriate treatment strategy. This review deals with the criteria for differential diagnosis of these neoplasms, with emphasis on recent advances in immunohistochemistry and molecular biology, as well as with previous progress in electron microscopy. Through careful microscopic examination of haematoxylin and eosin-stained sections, in the light of clinical information and imaging data, a list of differential diagnoses can be made and an appropriate panel of antibodies can be chosen to further categorize the tumour. An initial panel including cytokeratins, synaptophysin, S100 protein, desmin and CD45 may allow the classification of most lesions or may help to narrow the list of differential diagnoses. Further refinement can be obtained through second-line markers, including in-situ hybridization for Epstein-Barr virus, other neuroendocrine markers, melanocytic markers, myogenin, CD99, other lymphocyte markers, and CD138 and light chains. Finally, molecular analysis can further assist in the recognition of specific entities such as nuclear protein in testis midline carcinoma, Ewing's sarcoma/peripheral neuroectodermal tumour, alveolar rhadbomyosarcoma, and poorly differentiated synovial sarcoma.

Sphenoid sinus basaloid squamous cell carcinoma presenting as a sellar mass: report a case with review of the literature

Basaloid squamous cell carcinoma (BSCC) is a distinctive variant of squamous cell carcinoma (SCC) with more aggressive behavior. It occurs preferentially in the upper aerodigestive tract. Sinonasal tract BSCC is uncommon, and only limited studies have been reported in literature. In these studies, most BSCCs arose from the nasal mucosa with or without extension to the paranasal sinuses. Rare reported cases of BSCC involved only the paranasal sinus. In this report, we present a case of a female patient with a sphenoid sinus mass. Clinically, the patient had progressively decreasing vision and headache. Magnetic resonance imaging (MRI) and computerized tomographic (CT) scan showed an infiltrating tumor mass involving the sphenoid sinus and the sella with compression of the optic nerve. Pathologic examination revealed an invasive basaloid epithelial neoplasm that was arranged in lobules, nests and cords. The tumor also showed palisading of peripheral cells, focal abrupt squamous differentiation and in situ carcinoma in the surface mucosa. In the immunohistochemical studies, this tumor revealed a strongly positive nuclear staining for p63. The morphologic and ancillary studies indicated a BSCC. To the best of our knowledge, this is the first report of sinonasal tract BSCC that mainly involved the sphenoid bone and sella. In this region, BSCC should be distinguished from benign and malignant neoplasms that more often affect sella and base of skull, such as pituitary adenoma with extensive necrosis, small cell neuroendocrine carcinoma (SCNC), olfactory neuroblastoma, malignant germ cell tumor, paranasal adenoid cystic carcinoma (ACC), and a variety of metastatic malignancies.

Diagnostic protein marker patterns in squamous cervical cancer

PURPOSE

Cervical cancer is the second most prevalent malignancy of women. Our aim was to identify additional marker protein patterns for objective diagnosis of squamous cervical cancer (SCC).

EXPERIMENTAL DESIGN

Collected tissue biopsies of SCC, squamous vaginal cancer (SVC), normal cervical and vaginal mucosa were subjected to 2-DE, SameSpot analysis, MALDI-TOF-MS protein identification, and analysis of the expression of selected proteins by immunohistochemistry.

RESULTS

In 148 protein spots selected by the difference in expression 99 proteins were identified. A differential protein pattern for SCC was, e.g. over-expressed (OE) eukaryotic translation initiation factor 3-2β, neutrophil cytosolic factor 2, annexin A6 (ANXA6), for SVC it was OE cathepsin D, γ-catenin, RAB2A, for both cancers it was OE apolipoprotein E, tropomyosin 3, HSPA8, and underexpressed cytokeratin 13, osteoglycin. In SCC nuclear expression of neutrophil cytosolic factor 2, PRDX2, HSP27 (nine of ten cases), ANXA6 (nine of ten cases) was observed while tropomyosin 4 was expressed only in two of ten cases. There was 81.1% (43/53) agreement between the expression of protein spots and the immune expression of proteins (www.proteinatlas.org).

CONCLUSIONS AND CLINICAL RELEVANCE

SCC is characterized by specific tissue marker protein patterns that allow objective detection of the disease. They can become a basis for objective automated cytology-based screening and improve current diagnostics of SCC.