Basaloid squamous cell carcinoma of the sinonasal tract

Ameloblastic Carcinoma With Orbital Invasion

Ameloblastic carcinomas are malignant tumors arising from the odontogenic epithelium and defined as having features of ameloblastic differentiation in addition to cytological features of malignancy. Orbital involvement is rare and generally involves invasion of the orbital floor, apex, or soft tissue. This report describes an advanced presentation of ameloblastic carcinoma with orbital invasion and provides a review of the literature. A 58-year-old male presented with a 2-year history of a mid-facial mass, causing intracranial invasion and distortion of most skull foramina, nasopharynx, nasal cavity, and both orbits. Notably, there was an en-plaque pattern of circumferential tracking of the tumor along both orbital walls without invasion beyond the extraconal space, causing compression of the orbital apex and proptosis. Histology demonstrated nests of ameloblastic carcinoma and the advanced tumor was deemed nonresectable, with treatment being palliative.

Elective Neck Dissection in cT1-4 N0M0 Head and Neck Basaloid Carcinoma

OBJECTIVE

To investigate the survival benefit of elective neck dissection (END) over neck observation in surgically resected cT1-4 N0M0 head and neck basaloid carcinoma (HNBC).

STUDY DESIGN

Retrospective cohort study.

SETTING

The 2006 to 2017 hospital-based National Cancer Database.

METHODS

Patients with surgically resected cT1-4 N0M0 HNBC were selected. Linear, binary logistic, Kaplan-Meier, and Cox proportional hazards regression models were implemented.

RESULTS

Of 857 patients satisfying inclusion criteria, the majority were male (77.0%) and white (88.1%) with disease of the oral cavity (21.5%) or oropharynx (42.9%) classified as high grade (76.9%) and cT1-2 (72.9%). 389 (45.4%) patients underwent END. END utilization between 2006 and 2017 increased for cT1-2 disease (33.3% vs 56.9%, R2 = .699) but remained relatively constant for cT3-4 disease (66.7% vs 57.9%, R2 = .062). One-hundred and fifteen (29.6%) ENDs detected occult nodal metastases (ONMs). The 5-year overall survival (OS) of patients undergoing neck observation and END was 65.6% and 66.8%, respectively (P = .652). END was not associated with improved OS in survival analyses stratified by patient demographics, clinicopathologic features, and adjuvant therapy. Compared with surgery alone, adjuvant radiotherapy (adjusted hazard ratio: 0.74, 95% confidence interval [CI]: 0.57-0.97, P = .031) was associated with improved OS. END (hazard ratio [HR]: 0.96, 95% CI: 0.71-1.28, P = .770) and ONM (HR: 1.12, 95% CI: 0.78-1.61, P = .551) were not associated with OS.

CONCLUSION

END is performed in nearly half of patients with HNBC but is not associated with improved OS, even after stratifying survival analyses by patient demographics, clinicopathologic features, and adjuvant therapy. The rate of ONM approaching 30%, however, justifies inclusion of END in the surgical management of HNBC.

Basaloid squamous cell carcinoma in the mandibular alveolus: A rare case report with differential diagnosis

ABSTRACT

Basaloid squamous cell carcinoma (BSCC) is a distinct, high-grade variant of oral squamous cell carcinoma (OSCC) with a poor prognosis. In the head and neck region, the most common sites are the epiglottis, piriform sinus, and tongue base. Other less common sites include the floor of the mouth, oral mucosa, palate, tonsils, nasopharynx, and trachea. In the present report, the unusual case of a 69-year-old male is presented; the patient exhibited ulceroproliferative growth involving the lower alveolus. Incisional biopsy was done and the hematoxylin and eosin-stained sections revealed tumor islands with dysplastic oral epithelial cells invading the underlying connective tissue as islands, cords, and nests. The presence of palisading basaloid cells with a central area of comedo necrosis and keratin formation on the islands revealed the diagnosis of BSCC. Immunohistochemistry demonstrated positive staining for proliferative cell nuclear antigen (PCNA) and pan-cytokeratin. The patient is still under treatment and follow-up.

Basaloid squamous cell carcinoma of the larynx: A rare case report

INTRODUCTION AND IMPORTANCE

Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive subtype of squamous cell carcinoma. BSCC in the larynx is an extremely rare occurrence, with only a few cases reported in the medical literature. This case report aims to shed light on the clinical presentation, diagnostic challenges, histopathological features, and therapeutic considerations associated with this rare entity.

CASE PRESENTATION

This case report describes a 65-year-old male patient who presented with hoarseness and dyspnea. Laryngoscopy revealed a 2.5 cm pedunculated lesion on the left vocal cord. The patient underwent a laryngectomy, and the histopathological examination of the excised specimen confirmed the diagnosis of BSCC.

CLINICAL DISCUSSION

BSCC of the larynx is a rare malignancy comprising less than 1 % of laryngeal cancers. Clinical features often overlap those of squamous cell carcinoma, such as hoarseness, progressive breathing difficulties, and swallowing issues. Treatment approaches vary, with some opting for neo-adjuvant radiotherapy before surgery, like in this case, while others favor surgical excision as the primary treatment, supplemented by adjuvant chemo- or radiotherapy in certain cases.

CONCLUSION

Basaloid squamous cell carcinoma is a rare variant of squamous cell carcinoma. Clinicians and pathologists should be aware of the distinctive characteristics of BSCC and its potential clinical aggressiveness. While rare, early recognition and appropriate management are essential for achieving favorable outcomes in patients with this challenging condition.

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

BACKGROUND

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

METHODS

Review.

RESULTS

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

CONCLUSION

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

Successful Treatment of Basaloid Squamous Cell Carcinoma of the Nasal Cavity With Brain Invasion

Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive subtype of squamous cell carcinoma (SCC). To date, no consensus on the treatment of BSCC has been established yet, especially in cases of invasion of the skull base. In addition, long-term prognosis has not been reported in T4b cases. Herein, we report the case of a 36-year-old Japanese man with locally advanced nasal BSCC that directly invaded the skull base and the brain. The patient was then treated with induction chemotherapy (IC). Owing to his good response to IC, we planned and performed en bloc resection followed by adjuvant proton beam therapy (PBT). Follow-up examinations five years after treatment showed no evidence of recurrence. This is the first report of IC followed by radical surgery and adjuvant PBT in a patient with T4b. IC has the potential to play an important role in treatment strategies.

Analysis of Human Papillomavirus (HPV) and Polyomaviruses (HPyVs) in Adenoid Cystic Carcinoma (AdCC) of the Head and Neck Region Reveals Three HPV-Positive Cases with Adenoid Cystic-like Features

An aetiological role of human papillomavirus (HPV) and/or human polyomaviruses (HPyVs) has been proposed in adenoid cystic carcinoma (AdCC). Moreover, HPV-related multiphenotypic carcinoma (HMSC) was recently introduced as an emerging entity of the sinonasal region. Here, we primarily want to study the role of HPV/HPyV in a large AdCC cohort and, secondly, possibly identify and characterize HMSC. Tumour DNA from 68 patients initially diagnosed with AdCC between 2000 and 2012 was, therefore, tested for 27 HPV types and 10 HPyVs. HPV DNA-positive samples were micromorphologically re-evaluated, further stained for p16^INK4a, S100, p63 and CD117 and tested for the presence of the MYB-NFIB fusion transcript. Notably, no samples were HPyV-positive, while one sinonasal and two tonsillar carcinomas were HPV- and p16-positive. After re-evaluating the micromorphology, immunohistochemistry and presence of fusion transcripts, all tumours had the same appearance and fitted within the diagnosis of HMSC, but in all these three cases, the morphology of the HMSC and basaloid squamous cell carcinoma was overlapping. We conclude that HPV and HPyV have no major role in AdCC. However, based on our data, we also suggest that HMSC should be considered as a basaloid variant of squamous cell carcinoma, and not its own entity, until better characterized.

Mismatch Repair Deficiency and Somatic Mutations in Human Sinonasal Tumors

Simple Summary

Sinonasal carcinomas are rare tumors with an overall poor prognosis. Due to limitations in local therapeutic approaches, systemic neo-adjuvant or adjuvant therapies are becoming increasingly important in order to improve patient outcome. This study aimed to examine potentially therapeutic targetable molecular alterations in different sinonasal tumors, including deficiency in mismatch repair proteins and microsatellite instability as well as driver mutations. According to our results, immunohistochemical (IHC) analysis of mismatch repair (MMR) proteins and sequencing-based panel analysis should be integrated into the diagnostics of clinically aggressive inverted sinonasal papilloma (ISP) and sinonasal squamous cell carcinoma (SNSCC) in order to enable the therapeutic possibility of a targeted therapy.

Abstract

Due to limitations in local therapy approaches for sinonasal tumors, improvement in systemic therapies plays a pivotal role for prolongation of the patient’s survival. The aim of this study was to examine potential biomarkers, including deficiency in mismatch repair proteins (dMMR)/microsatellite instability (MSI-H) in sinonasal cancers and their precancerous lesions. A comprehensive analysis of 10 sinonasal cancer cell lines by whole exome sequencing, screening 174 sinonasal tumors by immunohistochemistry (IHC) for mismatch repair deficiency and next generation sequencing (NGS) of 136 tumor samples revealed a dMMR/MSI-H sinonasal squamous cell carcinoma (SNSCC) cell line based on a somatic missense mutation in MLH1 and an overall frequency of dMMR/MSI-H SNSCC of 3.2% (4/125). Targetable EGFR mutations were found in 89.3% (25/28) of inverted sinonasal papilloma (ISP) and in 60% (6/10) of ISP-associated carcinomas. While PIK3CA and EGFR mutations were not mutually exclusive, KRAS mutated tumors were an EGFR-wildtype. The effect of potential driver mutations in FGFR2, FGFR3, BRAF, HRAS, MAP2K1, PTEN, NOTCH1 and CARD11 need further investigation. Our results suggest that biomarker testing, including MMR-IHC and NGS panel analysis, should be integrated into the diagnostics of clinically aggressive ISPs and SNSCC to assess prognosis and facilitate therapeutic decisions.

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.

Constitutive Hedgehog/GLI2 signaling drives extracutaneous basaloid squamous cell carcinoma development and bone remodeling

Uncontrolled activation of the Hedgehog (Hh) signaling pathway, operating through GLI transcription factors, plays a central role in the pathogenesis of cutaneous basal cell carcinoma and contributes to the development of several malignancies arising in extracutaneous sites. We now report that K5-tTA;tetO-Gli2 bitransgenic mice develop distinctive epithelial tumors within their jaws. These tumors consist of large masses of highly proliferative, monomorphous, basaloid cells with scattered foci of keratinization and central necrosis, mimicking human basaloid squamous cell carcinoma (BSCC), an aggressive upper aerodigestive tract tumor. Like human BSCC, these tumors express epidermal basal keratins, and differentiation-specific keratins within squamous foci. Mouse BSCCs express high levels of Gli2 and Hh target genes, including Gli1 and Ptch1, which we show are also upregulated in a subset of human BSCCs. Mouse BSCCs appear to arise from distinct epithelial sites, including the gingival junctional epithelium and epithelial rests of Malassez, a proposed stem cell compartment. Although Gli2 transgene expression is restricted to epithelial cells, we also detect striking alterations in bone adjacent to BSCCs, with activated osteoblasts, osteoclasts, and osteal macrophages, indicative of active bone remodeling. Gli2 transgene inactivation resulted in rapid BSCC regression and reversal of the bone remodeling phenotype. This first-reported mouse model of BSCC supports the concept that uncontrolled Hh signaling plays a central role in the pathogenesis of a subset of human BSCCs, points to Hh/GLI2 signaling as a potential therapeutic target, and provides a powerful new tool for probing the mechanistic underpinnings of tumor-associated bone remodeling.

A rare case of nasal Schneiderian (inverted) papilloma associated with basaloid squamous cell carcinoma

Sinonasal inverted papilloma (IP) is a benign, locally aggressive epithelial neoplasm. In less than 9% of cases it is associated with malignancies, typically conventional squamous cell carcinomas (SCC), while other histological variants have been less frequently reported. We describe the third case of basaloid squamous cell carcinoma (BSCC) arising in nasal IP. An 81-year-old female patient presented with a pinkish irregular lesion on the nasal septum. Biopsy was consistent with IP and carcinoma in situ. Two surgical procedures were needed to obtain radical excision. Histology on the surgical specimen revealed BSCC. Seven months after surgery, there was no evidence of disease recurrence. Although IP is more frequently associated with conventional SCC, other malignancies should be considered. The histological differential diagnosis should be supported by immunohistochemistry. The generally-recommended treatment for sinonasal BSCC is complete surgical resection, although this may be a problem in multifocal distributions, as in the present case.

Oropharyngeal Squamous Cell Carcinoma in 390 Patients: Analysis of Clinical and Histological Criteria Which Significantly Impact Outcome

This study evaluates the prognostic impact of several factors in oropharyngeal squamous cell carcinoma (OPSCC), controlling for human papillomavirus (HPV)-associated tumors and stage (American Joint Committee on Cancer 8th edition). All patients in Southern California Permanente Medical Group diagnosed with OPSCC between 2006 and 2012 tested for p16 immunohistochemistry were included. Review of all pathology materials was combined with central p16 testing. Multivariable analyses were performed. The cohort of 390 patients included 342 p16-positive and 48 p16-negative tumors. For all-comers, on univariate analysis, the following factors, when present, were associated with improved patient survival: p16-positive tumor (n = 324, p < 0.001); crypt versus surface tumor location (n = 312, p = 0.004); nonkeratinizing type (n = 309, p < 0.0001); nonkeratinizing with maturation type (n = 37, p < 0.0001); basaloid pattern (n = 284, p = 0.005); and a broad, pushing border of infiltration (n = 282, p = 0.004). Inferior survival outcomes were observed with: age ≥ 55 years (p < 0.0001); ≥ 10 pack-year smoking history (n = 183, p = 0.003); increasing tumor stage (p < 0.0001); overt radiographic extranodal extension (ORENE) (n = 58, p < 0.0001); low level IV/Vb lymph node involvement (n = 45, p = 0.0002); a jagged pattern of infiltration (n = 76, p = 0.0004); tumor ulceration (n = 76, p = 0.0004); absent lymphocytic infiltrate (p < 0.0001); and concurrent dysplasia (n = 125, p = 0.009). On multivariable analysis, accounting for patient age, smoking history ≥ 10 pack-years, and TNM stage, for patients with p16-positive disease, advanced TNM stage (p = 0.007), the presence of ORENE (p = 0.0002), and low-neck lymphadenopathy (p = 0.0001) were independent negative prognostic factors for disease free survival (DFS). Older age (p < 0.0001), smoking history ≥ 10 pack-years (p = 0.02), advanced TNM stage (p = 0.0002), ORENE (p = 0.004), and low-neck lymphadenopathy (p = 0.002) were independent negative prognostic factors for OS. Among patients with p16-positive OPSCC, older age, smoking history, advanced stage, ORENE, and low-neck lymphadenopathy were significant negative prognostic factors for DFS and/or OS. Further refinement of staging to incorporate additional lymph node findings may be warranted.

Laryngeal Basaloid Squamous Cell Carcinoma with a Substantial Spindle Cell Component: Case Presentation and Updated Review of Literature

Basaloid squamous cell carcinoma with spindle cell component is an uncommon aggressive variety of squamous cell carcinoma with only a few reported cases in literature. Histologically a combination of basaloid squamous cell carcinoma and spindle cell squamous cell carcinoma is appreciated and immunohistochemistry serves a role in differentiation from malignant neoplasms of salivary gland or neuro-endocrine origin. Prime treatment modality is combination of surgery and external beam radiotherapy. A case of basaloid squamous cell carcinoma with proliferation of bizarre mesenchymal component is being reported here with an updated literature review.

Sinonasal adenoid cystic carcinoma-role of on-site FNAC: a case report

Background

Adenoid cystic carcinoma (ACC), a rare tumor of epithelial cell origin, commonly arises from the major salivary glands. Uncommonly it may be found outside the salivary glands and it's especially rare in the nasal cavity.

Case presentation

A 71-year female had complaints of swelling at the base of nose, Fine needle aspiration (FNA) from the swelling revealed features of adenoid cystic carcinoma; cell block & IHC for CD-117 was positive.

Conclusions

Sino-nasal ACC (SNACC) continues to pose diagnostic and therapeutic challenges to clinicians. Due to its rarity & vague presentation, early diagnosis requires a high index of suspicion. FNA can be used as an invaluable diagnostic tool in the evaluation of these lesions. Since it's incidence in sinonasal region is rare; our attempt to report this case will heighten the physician's awareness of this disease, helping further treatment.

Updates on Immunohistochemical and Molecular Markers in Selected Head and Neck Diagnostic Problems

CONTEXT

- The head and neck regions have complex anatomic structures. They are not exempted from the rare occurrences of highly unusual, diagnostically challenging malignant neoplasms and mimickers.

OBJECTIVE

- To review and update the utility of immunohistochemistry and molecular biomarkers and to pursue diagnostic accuracy on selected rare neoplasms, especially some poorly differentiated malignancies.

DATA SOURCES

- Personal experience and information from the literature.

CONCLUSIONS

- Head and neck tumors include neoplasms originating from heterogeneous tissue. Using the selected clinical cases, this review illustrates a continuous development of emerging molecular-genetic techniques to assist in the interpretation of uncommon, often poorly differentiated, highly malignant neoplasms. The diagnostic results are appropriately transmitted to the oncologists, radiation oncologists, and surgeons to create a coordinated plan of care for patients with these unusual disorders affecting the head and neck.

Evaluation of Patients with Sinonasal and Ventral Skull Base Malignancies

A wide variety of tumors present in the sinonasal and ventral skull base. Patients often have nonspecific symptoms initially and present with advanced tumors, affecting the orbit and other adjacent structures. Evaluation of these malignancies with modern imaging techniques can define tumor invasion, but biopsy is often required to establish a diagnosis because most have a nonspecific appearance. A thorough understanding of the anatomy is the key to treatment planning, and a multidisciplinary approach determines the optimal strategy.

Laryngeal Dysplasia, Squamous Cell Carcinoma, and Variants

Squamous cell carcinoma (SCC) is a malignant epithelial tumor showing evidence of squamous differentiation. It is the most common malignancy of the larynx, with several variants (verrucous, exophytic or papillary, spindle-cell, basaloid, acantholytic, adenosquamous) recognized, with well-established precursor lesions. Dysplasia is now separated into only low-grade and high-grade categories. Each SCC variant has unique cytomorphologic features and histologic differential diagnoses that are important to consider, as management and outcomes are different.

Squamous cell carcinoma of the upper aerodigestive tract: dysplasia and select variants

Upper aerodigestive tract (UADT) mucosal premalignant lesions include non-keratinizing and keratinizing intraepithelial dysplasia. The keratinizing type of intraepithelial dysplasia represents the majority of UADT dysplasias. Historically, grading of UADT dysplasias has followed a three tier system to include mild, moderate and severe dysplasia. Recent recommendations have introduced a two tier grading scheme to including low-grade (ie, mild dysplasia) and high-grade (moderate and severe dysplasia/carcinoma in situ) providing for better consensus among pathologists in the interpretation of such dysplastic lesions. Squamous cell carcinoma is the most common malignant neoplasm of the UADT. Several variants of squamous cell carcinoma are recognized among which the more common types include papillary squamous cell carcinoma, verrucous carcinoma, spindle cell squamous cell carcinoma (sarcomatoid carcinoma) and basaloid squamous cell carcinoma. Each of these variants of squamous cell carcinoma poses diagnostic challenges and each correlates to specific therapy and prognosis. This review details the proposed update in the grading of UADT dysplasia to a two-tiered system as well as providing the key diagnostic features for select variants of squamous cell carcinoma.

Basaloid squamous cell carcinoma of the sinonasal tract with metastasis to the liver: a case report and literature review

Basaloid squamous cell carcinoma (BSCC) is a rare subtype of squamous cell carcinoma. To date, only 95 cases of sinonasal BSCC have been reported in the English-language literature, and they account for 5% of all cases of head and neck BSCC. We describe what we believe is only the second reported case of a sinonasal tract BSCC that metastasized to the liver. The patient was a 36-year-old woman who presented with right-sided nasal obstruction and a foul-smelling discharge. Clinical examination and imaging identified a large, lobulated, enhancing mass in the right nasal cavity. Following excision of the mass, the patient was scheduled for radiotherapy. However, before it could be administered, follow-up imaging detected a metastasis to the liver and lung, and the patient was switched to chemotherapy. Initially, she responded well clinically, but at 5 months postoperatively, a follow-up CT showed an increasing metastatic presence in the liver and bone. The patient died of her disease 1 year after surgery.

Basaloid squamous cell carcinoma arising in an inverted papilloma in the nasal cavity: A case report and review

Basaloid squamous cell carcinoma (BSCC) is a histologically distinctive variant of squamous cell carcinoma comprising basal cell carcinoma and squamous cell carcinoma. BSCC is aggressive and shows a poor prognosis because of frequent lymph node invasion and distant metastases. BSCC preferentially occurs in the cervix, thymus, and esophagus and is uncommonly found in the head and neck region. BSCC in the nasal cavity or paranasal sinus is particularly rare. Inverted papilloma is an uncommon, benign tumor with a propensity to be associated with malignancy; however, BSCC arising in an inverted papilloma has never been reported. Here we report a case of a 56-year-old woman with BSCC arising in an inverted papilloma in the nasal cavity. The woman was referred to our hospital for epistaxis, nasal congestion, and dysphagia. A tumor was observed to completely occupy the left nasal cavity. The biopsy specimen was histologically diagnosed as papilloma. Computed tomography demonstrated a tumor with heterogeneous contrast effect occupying the left nasal cavity; however, extra-nasal tract extension was not observed. We performed endoscopic excision of the tumor. Microscopic findings confirmed the diagnosis of BSCC arising from an inverted papilloma. No tumor recurrence has been observed for 13 months after surgery.

Nasal Cavity and Paranasal Sinuses

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

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

Sinonasal small round blue cell tumors: An approach to diagnosis

The differential diagnosis for small round cell tumors in the sinonasal tract is diverse and as the body of literature documenting not only uncommon presentations but also availability of ancillary studies grows, so does the need for a reminder to take a conservative and thorough approach before rendering a diagnosis. Small tissue samples are particularly problematic, with limitations that include volume of tumor cells available for studies, lack of architectural context and a non-specific gross description. Incorporation of patient history and presentation, radiologic findings, clinical impression and concurrent studies often guide the course of studies performed by the pathologist. If these are non-specific, the pathologist may need to perform ancillary studies, including a broad panel of immunohistochemical stains and molecular studies. If tissue is limited, a precise classification may not be achievable. Although the expectation to render a definitive diagnosis is high, the pathologist should never feel compelled to go further with a diagnosis than the tissue itself supports.

Basaloid squamous cell carcinoma of the maxilla

Basaloid squamous cell carcinoma (BSCC) is a distinctive aggressive variant of squamous cell carcinoma. We present a case of a 60-year-old man with tender swelling in the right cheek region for 6 months and continuous unilateral nasal discharge for 2 months. Extraoral examination revealed an ovoid, well-defined swelling from the right infraorbital rim to the angle of the mouth superoinferiorly and the right lateral wall of the nose to preauricular region anteroposteriorly. Intraorally, an ulceroproliferative growth from right upper gingivobuccal sulcus to mid palatine raphe with bicortical expansion was evident. CT revealed a hypodense mass obliterating the right maxillary sinus. Histopathology showed closely packed basaloid cells, with hyperchromatic palisading nuclei, arranged in a solid pattern with a lobular configuration. Prominent areas of comedo necrosis and keratin pearl formation were seen. These features suggested BSCC. The patient underwent surgical excision with adjuvant radiation but was lost to follow-up after 6 months of radiation therapy.

John MA. Basaloid squamous cell carcinoma of the maxilla: Report of a case and literature review

PURPOSE

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma characterized by a highly aggressive clinical course. Though typically found in the larynx, oropharynx, and hypopharynx, we report a rare case of BSCC originating in the maxillary sinus in an otherwise healthy 32-year-old male.

MATERIALS AND METHODS

Single case report of a patient with BSCC of the maxillary sinus and retrospective chart review of all cases of BSCC of the maxilla at a single academic institution between January 1, 1986 and December 31, 2013. The MEDLINE database was additionally queried for all case series or reports of BSCC arising in the maxilla, and pertinent clinical data were extracted.

RESULTS

The clinical presentation, disease course, and management of a patient with BSCC of the maxilla are presented. In this recent case, the patient presented with persistent alveolar pain and a nonhealing tooth infection. Radiographic studies demonstrated a large necrotic mass in the left maxillary sinus that was biopsy-proven as BSCC. The patient underwent surgical resection followed by postoperative radiation without complications.

CONCLUSIONS

BSCC of the maxilla is a rare oncologic entity that may progress to late disease stage without obvious clinical signs or symptoms. Optimal treatment involves complete surgical resection followed by postoperative.

The expanding family of SMARCB1(INI1)-deficient neoplasia: implications of phenotypic, biological, and molecular heterogeneity

Since the description of atypical teratoid/rhabdoid tumors of the central nervous system and renal/extrarenal malignant rhabdoid tumors in children, the clinicopathologic spectrum of neoplasms having in common a highly variable rhabdoid cell component (0% to 100%) and consistent loss of nuclear SMARCB1 (INI1) expression has been steadily expanding to include cribriform neuroepithelial tumor of the ventricle, renal medullary carcinoma and a subset of collecting duct carcinoma, epithelioid sarcoma, subsets of miscellaneous benign and malignant soft tissue tumors, and rare rhabdoid carcinoma variants of gastroenteropancreatic, sinonasal, and genitourinary tract origin. Although a majority of SMARCB1-deficient neoplasms arise de novo, the origin of SMARCB1-deficient neoplasia in the background of a phenotypically or genetically definable differentiated SMARCB1-intact "parent neoplasm" has been convincingly demonstrated, highlighting the rare occurrence of rhabdoid tumors as "double-hit neoplasia." As a group, SMARCB1-deficient neoplasms occur over a wide age range (0 to 80 y), may be devoid of rhabdoid cells or display uniform rhabdoid morphology, and follow a clinical course that varies from benign to highly aggressive causing death within a few months irrespective of aggressive multimodality therapy. Generally applicable criteria that would permit easy recognition of these uncommon neoplasms do not exist. Diagnosis is based on site-specific and entity-specific sets of clinicopathologic, immunophenotypic, and/or molecular criteria. SMARCB1 immunohistochemistry has emerged as a valuable tool in confirming or screening for SMARCB1-deficient neoplasms. This review summarizes the different phenotypic and topographic subgroups of SMARCB1-deficient neoplasms including sporadic and familial, benign and malignant, and rhabdoid and nonrhabdoid variants, highlighting their phenotypic heterogeneity and molecular complexity.

SMARCB1(INI1)-deficient sinonasal basaloid carcinoma: a novel member of the expanding family of SMARCB1-deficient neoplasms

Poorly differentiated sinonasal carcinomas are a heterogenous group of aggressive neoplasms that encompasses squamous cell carcinoma including basaloid variant, lymphoepithelial carcinoma, sinonasal undifferentiated carcinoma, and neuroendocrine-type small cell carcinoma. We herein describe 3 cases of a hitherto unreported variant combining features of basaloid carcinoma with variable intermingled rhabdoid cells. Patients were 2 women (aged 28 and 35) and a man (52 y) who presented with sinonasal masses. All had advanced local disease with bone involvement (pT4). None had a history of irradiation or a family history of rhabdoid tumors. Treatment was surgery and adjuvant chemoradiation. One patient developed liver, lung, pleural, and pericardial metastases (63 mo) and is currently (70 mo) alive under palliative treatment. Another developed recurrent cervical lymph node metastases and died of disease 8.5 years later. The youngest patient was disease-free at last follow-up 7 years later. Histologic features were very similar in all 3 cases and showed intimate admixture of compact basaloid cell nests with peripheral palisading, perivascular pseudorosettes, and a few scattered rhabdoid cells. Rhabdoid cells were more extensive in the metastasis in 1 case but formed a minor inconspicuous component in the primary tumors in all cases. Striking features common to all cases were (1) basaloid “blue” appearance at low power, (2) papilloma-like exophytic component, (3) extensive pagetoid surface growth with prominent denuding features, and (4) replacement of underlying mucous glands mimicking an inverted papilloma. Clear-cut origin from benign papilloma and overt squamous differentiation were lacking. Diffuse (2) or partial (1) p16 expression was noted, but all cases lacked human papillomavirus DNA by molecular tests. In situ hybridization was negative for Epstein-Barr virus. Immunohistochemistry showed diffuse expression of pancytokeratin. CK5 and vimentin showed intermingling of CK5⁺/vimentin⁻ basaloid and CK5⁻/vimentin⁺ rhabdoid cells. Complete loss of nuclear SMARCB1 expression was seen in all cases including also the denuding carcinoma in situ–like surface lesions. To our knowledge, this variant of sinonasal carcinoma has not been reported before. The identical features in all 3 cases suggest a specific disease rather than a nonspecific dedifferentiated phenotype. Awareness of this rare variant and thus reporting of additional cases is necessary for defining its full morphologic and biological spectrum.

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.

A literature review on oral basaloid squamous cell carcinomas, with special emphasis on etiology

In the recent years, basaloid squamous cell carcinomas (BSCCs) have gained attention because of (1) observation of a relative increase in the number of tumors arising particularly in head and neck sites, (2) identification of human papillomavirus (HPV) in BSCCs arising predominantly in the oropharynx, and (3) controversies that exist regarding the biological aggressiveness of the tumor. The objective of the present review was to address the issues mentioned above by focusing primarily on oral BSCCs, using literature that has been published in the English language up to 2013. According to the literature review, oral BSCCs were found to be relatively more common in elderly patients with a mean age of 64 years. A male predominance with a male/female ratio of 3:1 was observed. The predominant site was the tongue, with almost half of the reported cases occurring at this site, followed by the floor of the mouth and palate. With reference to habit history, majority were found to be tobacco and alcohol users. However, only 3 studies revealed data on HPV status of purely oral BSCC, and according to the results of these studies, of the 17 tumors tested, 4 had harbored high-risk HPV. Furthermore, most oral BSCCs were in an advanced clinical stage, namely, stage III or IV with T3 or T4 lesions and cervical lymph node metastasis at initial presentation, whereas 41% of patients had presented with local recurrences and 45% had died of the disease. In conclusion, although, the present literature review found enough evidence to consider tobacco and alcohol as risk factors for the development of oral BSCC, steps should be taken to fill the gap in our knowledge that exist with reference to contribution of oncoviruses, particularly HPV in the etiology of oral BSCC.

BerEp4, Cytokeratin 14, and Cytokeratin 17 Immunohistochemical Staining Aid in Differentiation of Basaloid Squamous Cell Carcinoma From Basal Cell Carcinoma With Squamous Metaplasia

Context.—Basaloid squamous cell carcinoma (bSCC) is an uncommon variant of squamous cell carcinoma, which may overlap histologically with basal cell carcinoma with squamous metaplasia (BCCm).

Objective.—To aid in the differentiation of these neoplasms using immunohistochemical staining because of the worse prognosis associated with bSCC.

Design.—Using immunohistochemical techniques, we investigated BerEp4, cytokeratin 17 (CK17), and cytokeratin 14 (CK14) protein expression in 25 cases of bSCC (8 cutaneous [32%], 12 aerodigestive tract [48%], and 5 lymph node metastases [20%]) and 43 cases of BCCm (39 cutaneous [91%], and 4 metastases [9%]). An immunoreactivity score was assigned using the percentage of tumor cells staining and the pattern of expression. Interobserver agreement for 2 independent pathologists was assessed using a κ coefficient.

Results.—The mean percentage of staining was significantly higher in BCCm, compared with bSCC (BerEp4, P = .006; CK17, P &lt; .001; CK14, P &lt; .001; unpaired t test), with 58% of BCCm cases (25 of 43) displaying diffuse staining for all markers, and nearly all (98%; 42 of 43) displaying diffuse staining for CK17 and CK14. In contrast, no bSCC cases (0%) displayed diffuse staining for all 3 markers, and only 8% (2 of 25) displayed diffuse staining for CK17 and CK14. High interobserver agreement was determined.

Conclusions.—BerEp4 alone is unreliable for differentiation between BCCm and bSCC, and the addition of either CK14 or CK17 will augment the sensitivity and negative predictive value of BerEp4 staining in BCCm and bSCC diagnosis.

Sinonasal tract and nasopharyngeal adenoid cystic carcinoma: a clinicopathologic and immunophenotypic study of 86 cases

Primary sinonasal tract and nasopharyngeal adenoid cystic carcinomas (STACC) are uncommon tumors that are frequently misclassified, resulting in inappropriate clinical management. Eighty-six cases of STACC included 45 females and 41 males, aged 12-91 years (mean 54.4 years). Patients presented most frequently with obstructive symptoms (n = 54), followed by epistaxis (n = 23), auditory symptoms (n = 12), nerve symptoms (n = 11), nasal discharge (n = 11), and/or visual symptoms (n = 10), present for a mean of 18.2 months. The tumors involved the nasal cavity alone (n = 25), nasopharynx alone (n = 13), maxillary sinus alone (n = 4), or a combination of the nasal cavity and paranasal sinuses (n = 44), with a mean size of 3.7 cm. Patients presented equally between low and high stage disease: stage I and II (n = 42) or stage III and IV (n = 44) disease. Histologically, the tumors were invasive (bone: n = 66; neural: n = 47; lymphovascular: n = 33), composed of a variety of growth patterns, including cribriform (n = 33), tubular (n = 16), and solid (n = 9), although frequently a combination of these patterns was seen within a single tumor. Pleomorphism was mild with an intermediate N:C ratio in cells containing hyperchromatic nuclei. Reduplicated basement membrane and glycosaminoglycan material was commonly seen. Necrosis (n = 16) and atypical mitotic figures (n = 11) were infrequently present. Pleomorphic adenoma was present in 9 cases; de-differentiation was seen in two patients. Immunohistochemical studies showed positive reactions for pan-cytokeratin, CK7, CK5/6, CAM5.2, and EMA, with myoepithelial reactivity with SMA, p63, calponin, S100 protein and SMMHC. CD117, CEA, GFAP and p16 were variably present. CK20 and HR HPV were negative. STACC needs to be considered in the differential diagnosis of most sinonasal malignancies, particularly poorly differentiated carcinoma, olfactory neuroblastoma and pleomorphic adenoma. Surgery (n = 82), often accompanied by radiation therapy (n = 36), was generally employed. A majority of patients developed a recurrence (n = 52) 2-144 months after initial presentation. Overall mean follow-up was 19.4 years (range 0.4-37.5 years): 46 patients died with disease (mean 6.4 years); 5 were alive with disease (mean 5.4 years), and 35 patients were either alive or had died of unrelated causes (mean 16.3 years). ACC of the SNT is uncommon. Recurrences are common. The following parameters, when present, suggest an increased incidence of either recurrence or dying with disease: mixed site of involvement, high stage disease (stage IV), skull base involvement, tumor recurrence, a solid histology, perineural invasion, bone invasion, and lymphovascular invasion.

Sinonasal squamous cell carcinomas: clinical outcomes and predictive factors

This was a retrospective study of 33 patients treated for sinonasal squamous cell carcinoma between 1995 and 2008. Epidemiological, clinical, histological, and therapeutic aspects of this series of patients were analysed, and their impacts on overall survival and disease-free survival established using the Kaplan-Meier method. A search for prognostic factors was made using a log-rank test. There were 27 men. The average age at diagnosis was 64.7 years. Tobacco-smoking was found to be a risk factor in 24 patients (72.7%). The median follow-up was 66 months (range 0-99 months). Tumours were classified as T1 in 18.3%, T2 in 27.3%, T3 in 6%, and T4 in 48.5% of cases. Disease-free survival rates at 1 and 5 years were 58.5% and 46.1%, respectively, and overall survival rates were 70.3% and 40%, respectively. Overall survival was correlated to tumour status (TNM, American Joint Committee on Cancer) (P = 0.010) and involvement of key structures (skull base, dura mater, brain, orbit, cavernous sinus, infratemporal fossa, skin) (P = 0.049). Surgery followed by radiotherapy improved overall survival (P = 0.005) and disease-free survival (P = 0.028) when compared to other treatment modalities. When compared to surgery alone, it improved disease-free survival (P = 0.049) regardless of tumour stage.

Human papillomavirus-related carcinoma with adenoid cystic-like features: a peculiar variant of head and neck cancer restricted to the sinonasal tract

Human papillomavirus (HPV)-related carcinomas of the head and neck are characterized by a predilection for the oropharynx, a nonkeratinizing squamous morphology, and infection with the HPV 16 type; but comprehensive HPV testing across all head and neck sites has shown that the pathologic features of HPV-related carcinoma may be more wide ranging than initially anticipated. In particular, a subset of sinonasal carcinomas are HPV positive, and these include a variant that is histologically similar to adenoid cystic carcinoma (ACC). Cases were identified by retrospective and prospective analyses of head and neck carcinomas with ACC features. HPV analysis was performed using p16 immunohistochemistry and high-risk HPV in situ hybridization. HPV-positive cases were confirmed and typed using HPV type-specific quantitative polymerase chain reaction and further characterized on the basis of their immunohistochemical profile and MYB gene status. HPV was detected in 8 carcinomas of the sinonasal tract, but it was not detected in any ACCs arising outside of the sinonasal tract. The HPV types were 33 (n=6), 35 (n=1), and indeterminate (n=1). Six patients were women, and 2 were men, ranging in age from 40 to 73 years (mean 55 y). The carcinomas were characterized by a nested growth, a prominent basaloid component showing myoepithelial differentiation and forming microcystic spaces, and a minor epithelial component with ductal structures. Squamous differentiation, when present, was restricted to the surface epithelium. The carcinomas were not associated with the MYB gene rearrangement that characterizes a subset of ACCs. These cases draw attention to an unusual variant of HPV-related carcinoma that has a predilection for the sinonasal tract. Despite significant morphologic overlap with ACC, it is distinct in several respects including an association with surface squamous dysplasia, absence of the MYB gene rearrangement, and an association with HPV, particularly type 33. As HPV positivity confers distinct clinicopathologic characteristics when encountered in the oropharynx, a more comprehensive analysis of risk factors, response to therapy, and clinical outcomes is warranted for HPV-related carcinomas of the sinonasal tract.

Basaloid squamous cell carcinoma of the maxillary sinus: Report of two cases in association with cathepsin K expression

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma. The occurrence of BSCC in the nasal cavity is extremely rare. In the present study, two cases of BSCC occurring in the maxillary sinus are reported and the clinicopathological features and immunohistochemical characteristics of this rare tumor are discussed. Two patients, aged 85 (case 1) and 60 years (case 2), presented with nasal tumors and persistent nasal obstruction. In each case, the biopsy or resected specimen of the maxillary sinus tumor revealed an infiltrative proliferation of solid epithelial nests composed of basaloid cells exhibiting hyperchromatic nuclei without conspicuous nucleoli and scant cytoplasm. Mitotic figures were frequently observed and spherical hyalinized materials were present within the tumor nests. Immunohistochemically, the tumor cells exhibited diffuse positive immunoreactivity for p63 and perinuclear dot-like positivity for vimentin, leading to a final diagnosis of BSCC of the maxillary sinus. Furthermore, it was demonstrated for the first time in the two cases that cathepsin K, a cysteine protease with marked collagenolytic and elastolytic activities, was expressed in a diffuse manner. One patient (case 2) succumbed to multiple metastases, while the other (case 1) remains alive with the disease. In conclusion, it was demonstrated that cathepsin K was immunopositive in two cases of BSCC of the maxillary sinus and that it may be involved in tumor invasion by this highly aggressive carcinoma.

Neuroendocrine differentiation in head and neck squamous cell carcinoma

OBJECTIVE

Tumours with neuroendocrine differentiation frequently express chromogranin A, synaptophysin and somatostatin receptors. The role of neuroendocrine differentiation in head and neck squamous cell carcinoma is not yet clear.

METHOD

The presence of chromogranin A, synaptophysin and somatostatin receptors was studied immunohistochemically in 78 head and neck squamous cell carcinoma specimens.

RESULTS

Sparse chromogranin A expression was found in 41 per cent, associated with high chromogranin A messenger RNA expression and the presence of dense core granules. Low synaptophysin expression was found in 18 per cent. The highest staining scores were found for somatostatin receptor 5 (82 per cent), followed by somatostatin receptor 1 (69 per cent) and somatostatin receptor 2 (54 per cent), whereas somatostatin receptors 3 and 4 expression was low. Expression was not correlated with tumour stage or survival.

CONCLUSION

Cells with neuroendocrine differentiation are sparsely scattered in some head and neck squamous cell carcinomas. Their pathophysiological role is elusive. In contrast, somatostatin receptor and particularly somatostatin receptor 5 expression is frequent in head and neck squamous cell carcinoma. Somatostatin receptor expression is not considered to indicate neuroendocrine differentiation in head and neck squamous cell carcinoma.

Sinonasal carcinomas: epidemiology, pathology, and management

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

[Basaloid squamous carcinoma with a spindle cell component and osseous metaplasia presenting as a polyp of the hypopharynx]

We report a case of basaloid squamous carcinoma with a spindle cell component of the hypopharynx, in a 61-years-old-man. An excisional biopsy of a pedonculated and polypoid tumour was performed by endoscopy. The histologic examination revealed a biphasic tumour with both a basaloid carcinomatous and a spindle cell component. Focally, osseous metaplasia was seen. The spindle cell component demonstrated immunoreactivity with the p63 epithelial marker. The patient was treated with chemotherapy followed by radiotherapy. The patient has been free of disease for one year. It's the ninth case reported in the literature of a biphasic carcinoma with both a basaloid squamous and a spindle cell component and the first case with osseous metaplasia.

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.

Basaloid squamous cell carcinoma of the head and neck: report of 18 cases

Objective:

To evaluate the clinical course and pathological characteristics of basaloid head and neck squamous cell carcinoma.

Method:

Retrospective study of 18 cases of basaloid head and neck squamous cell carcinoma. Epidemiological, clinical and histological data were analysed and the Kaplan–Meier test used to estimate survival rates.

Results:

The majority of lesions were at an advanced stage. These lesions were primarily localised in the larynx, hypopharynx and oropharynx. Routine pre-therapeutic assessment of squamous cell carcinoma was performed. Pathological diagnosis was difficult, although immunostaining was extremely useful. Positive staining for KL1, MNF 116 and 34βE12 and negative immunostaining for chromogranin and synaptophysin were also important factors in obtaining a definitive diagnosis. In the majority of cases, treatment involved surgery and radiotherapy. The five-year survival rate was 5 per cent.

Conclusion:

Basaloid squamous cell carcinoma is an uncommon head and neck lesion, with a challenging histological diagnosis. These lesions must be carefully monitored due to their aggressive course, and require multimodality treatment.

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.

Human papillomavirus-positive basaloid squamous cell carcinomas of the upper aerodigestive tract: a distinct clinicopathologic and molecular subtype of basaloid squamous cell carcinoma

Basaloid squamous cell carcinoma of the upper aerodigestive tract is a rare, morphologically distinct variant of squamous cell carcinoma that is thought to be clinically aggressive. The histologic features are distinct from, but often confused with, those of human papillomavirus-related oropharyngeal nonkeratinizing squamous cell carcinoma. The role of human papillomavirus as an etiologic agent in true basaloid squamous cell carcinoma is controversial. The purpose of this study was to determine human papillomavirus prevalence and its clinicopathologic significance in upper aerodigestive tract tumors with true basaloid squamous cell carcinoma histology. Twenty-eight cases were identified, 12 in the oropharynx and 16 in the larynx and/or hypopharynx. High-risk human papillomavirus in situ hybridization and immunohistochemistry for p16 and p53 were performed. Nine (75%) of the oropharyngeal and none of the larynx/hypopharynx tumors were human papillomavirus positive. Human papillomavirus-positive tumors affected younger patients. No significant statistical differences in patients' sex, tumor stage, treatment modality, or length of follow-up were observed between the 2 groups. Viral status showed a strong, positive correlation with p16 (P < .001) and a strong, negative correlation with p53 (P < .0001) immunoreactivity. Overall survival was better for human papillomavirus-positive basaloid squamous cell carcinomas (P < .05), with 86% of patients alive at 3 years compared with 35.3% of patients with human papillomavirus-negative tumors. These findings suggest that a subset of basaloid squamous cell carcinomas is virally driven. These tumors occur almost exclusively in the oropharynx, are molecularly distinct from their human papillomavirus-negative counterparts, and have a more favorable clinical outcome.

Basaloid squamous cell carcinoma: two case reports

Basaloid squamous cell carcinoma (BSCC) is a rare and aggressive variant of squamous cell carcinoma (SCC) that occurs preferentially in the upper aerodigestive tract. We present two cases of BSCC, one arising in the conjunctiva and the other arising in a paranasal sinus. Clinical and pathological findings in these two cases, including immunohistochemistry is presented along with brief discussion of literature. To the best of our knowledge, this is the first report of BSCC of the conjunctiva. BSCC of the head and neck should be distinguished from adenoid cystic carcinoma, small cell neuroendocrine carcinoma, basal cell adenocarcinoma, adenosquamous carcinoma, squamous cell carcinoma, spindle cell squamous carcinoma, mucoepidermoid carcinoma, and adenoid cystic carcinoma.

[Head and neck squamous cell carcinoma: What's new in 2009]

Classical epidermoid carcinoma is the most frequent head and neck malignant neoplasm. Some particular variants are nevertheless of interest as they harbor a different prognosis, require specific care management and may arise from an alternate oncogenesis path. Best examples are verrucous carcinoma, basal-like or spindle cell carcinoma. Recent studies pointed out the critical role of infection with oncogenic HPV strains in the development of these carcinomas, especially in the oropharynx. In addition, HPV infection is changing the epidemiological profile of these cancers seems to have a prognostic value. New targeted therapies and prognostic markers will be discussed as they may dramatically improve the outcome of these tumors.

Thymic basaloid carcinoma: a clinicopathologic study of 12 cases, with a general discussion of basaloid carcinoma and its relationship with adenoid cystic carcinoma

Thymic carcinoma (primary carcinoma of the thymic epithelium; type C thymoma) is a rare malignancy. It usually presents in middle-aged to elderly patients and can exhibit a wide variety of morphologic appearances. Thymic basaloid carcinoma (thymic BC) is a particularly rare subtype, with less than 20 cases published in the English literature, mostly in the form of individual case reports. In this study, we present the clinicopathologic and immunohistochemical features of 12 new cases of thymic BC. There were 10 (83%) men and 2 (17%) women. Ages at the time of initial diagnosis ranged from 34 to 77 years (mean 55 y). The 2 most common manners of presentation were dyspnea on exertion (3 patients) and as an incidental finding on radiographic imaging (2 patients). Tumors ranged in size from 4.4 to 17 cm (mean 10.1 cm). One of 12 cases (8.3%) was associated with a multilocular thymic cyst. Immunohistochemistry was performed in 8 cases. Pan-cytokeratin was positive in all cases. CD117 (c-kit) was positive in 6 of 8 cases (75%), p63 was positive in 7 of 8 cases (88%), p53 was positive in 7 of 8 cases (88%), ranging from <10% to 90%, CD5 was focally positive in 3 of 8 cases (38%), collagen type IV was positive in 4 of 8 cases (50%), and proliferative index, as estimated by Ki67, ranged from <1% to approximately 15%. In 1 of 2 cases with sarcomatoid differentiation, Ki67 was greater than 80% in the sarcomatoid area. Cases were negative for thyroid transcription factor-1 (0 of 8), S-100 (0 of 7), and synaptophysin (0 of 7). Long-term data was available in 8 patients with an average follow-up of 30 months. Five patients died of their disease at an average of 34 months from the time of diagnosis. Of the remaining 3 patients, 1 had a stable recurrence and died at 4 years from unrelated causes, and 2 were alive without the evidence of disease at 12 and 7 months, respectively. Thymic BC, although previously regarded as a low-grade neoplasm, has shown that it is capable of aggressive behavior and significant mortality. In this paper, we review the pertinent literature and discuss the possible relationship of thymic BC with thymic adenoid cystic carcinoma, as well as BCs and adenoid cystic carcinomas at other sites.