Adenosquamous carcinoma of the head and neck: criteria for diagnosis in a study of 12 cases

The impact of histopathology on prognosis of squamous cell carcinoma of the larynx: can we do better?

Despite decades of progress, laryngeal squamous cell carcinoma (SCC) is still associated with significant morbidity and mortality worldwide. Additional biomarkers are needed to apply precision medicine and predict the clinical course. We reviewed and summarised routinely reported histopathologic features (e.g. subtypes of laryngeal SCC) along with promising potential biomarkers not yet routinely assessed using international guidelines. These include extra- vs intratumoural vascular and perineural invasion, tumour budding, depth of invasion, and tumour-infiltrating lymphocytes. We also address the problem of specimen quality and type (open approach vs endoscopic surgery) and the related limitations. High-risk human papillomavirus infection is another controversial issue to be discussed, being rare in laryngeal SCC, with an indeterminate prognostic significance and less reliable p16 overexpression as a surrogate marker of HPV infection. Further studies are warranted to address the applicability and to see which of the described parameters may help to better stratify patients with laryngeal SCC and should therefore be included in the pathology report.

Adenosquamous cell carcinoma of the head and neck: a retrospective single institution series

Objectives

Head and neck adenosquamous cell carcinoma (HN-ASCC) is a rare, aggressive neoplasm, with limited data reported in the literature. The aim of this study was to assess tumour behaviour and prognostic factors impacting overall survival (OS) in a retrospective, single institution series.

Methods

A retrospective study on patients affected by HN-ASCC who were treated surgically between 2002 and 2019 at the Department of Otorhinolaryngology - Head and Neck Surgery of the University of Brescia was conducted. Demographics, clinical data, OS, and relative prognostic factors were analysed.

Results

The study included 32 patients, with a median age of 66 years, mostly males (84.4%) and untreated (68.8%). Adjuvant treatments followed surgery in 28.1% of patients. Compared to conventional SCC, ASCC showed a higher proportion of cases arising in the larynx (40.6%); no difference was found in other features. Advanced (pT3-4) local stage at presentation (p = 0.023), perineural invasion (PNI, p = 0.01), and positive margins (p = 0.007) were independent negative prognostic factors for OS.

Conclusions

HN-ASCC is a rare, aggressive cancer, most frequently arising in the larynx of elderly males, usually diagnosed in an advanced local stage. OS is generally poor, affected by local advanced stage, PNI, and positive resection margins.

Sinonasal Adenosquamous Carcinoma - Morphology and Genetic Drivers Including Low- and High-Risk Human Papillomavirus mRNA, DEK::AFF2 Fusion, and MAML2 Rearrangement

BACKGROUND

Sinonasal adenosquamous carcinoma is rare, and there are almost no studies detailing morphology or characterizing their genetic driver events. Further, many authors have termed sinonasal tumors with combined squamous carcinoma and glands as mucoepidermoid carcinoma but none have analyzed for the presence of MAML2 rearrangement.

METHODS

Cases from 2014 to 2020 were collected and diagnosed using World Health Organization criteria. They were tested for p16 expression by immunohistochemistry (70% cut-off), DEK::AFF2 fusion by fluorescence in situ hybridization (FISH) and AFF2 immunohistochemistry, MAML2 rearrangement by FISH, and low- and high-risk HPV by RNA ISH and reverse transcription PCR, respectively. Detailed morphology and clinical features were reviewed.

RESULTS

There were 7 male (64%) and 4 female (36%) patients with a median age of 69 years, most Caucasian (10 of 11 or 91%). Most had tobacco exposure (8/11, 73%) and most presented with epistaxis, a visible nasal mass, and/or facial pain. Several had a precursor papillomas (3 of 11, 27%). The squamous component had variable keratinization, 5 of 11 (46%) of which would be described as keratinizing, 3 non-keratinizing, and 2 with mixed features. All had gland formation, by definition, and 2 of 11 (18%) had ciliated tumor cells. None of the 11 cases had MAML2 rearrangement and one had DEK::AFF2 fusion with associated positive nuclear AFF2 protein immunostaining. Most were p16 positive (7 of 11, 64%) and all 7 of these were hrHPV positive either by RNA ISH or RT-PCR. Two of the p16-negative tumors were positive for lrHPV by RNA ISH. Treatment included surgery alone (4 of 11, 36%), surgery with adjuvant radiation (5 of 11, 45%), and surgery with radiation and chemotherapy (2 of 11, 18%). Four of 11 patients (36%) suffered disease recurrence, two requiring re-operation and who were disease free at last follow-up, one receiving additional chemotherapy and who was alive with disease. The other elected to undergo palliative therapy and died of disease.

CONCLUSION

Sinonasal adenosquamous carcinoma is a somewhat heterogeneous tumor not infrequently arising ex papilloma and having various drivers including high- and low-risk HPV and rarely DEK::AFF2 fusion. The prognosis appears favorable when proper treatment is possible.

Clinicopathological practice in the differential diagnosis of mucoepidermoid carcinoma from neoplasms with mucinous component

Background

The differential diagnosis of mucoepidermoid carcinoma (MEC) from neoplasm undergoing mucinous features brings more pitfalls to pathologists. Combining specific MAML2 gene rearrangement and histological characteristics may be the solution.

Methods

Twenty-five tumors with mucinous components were selected for differential diagnosis of MEC. All the cases were detected for MAML2 gene rearrangement. The cases diagnosed as MEC were classified into four variants: classic, oncocytic, Warthin-like, and nonclassified, and they were graded using the Brandwein system. The histological characteristics of non-MECs were summarized for differential diagnosis. Univariate survival analysis was performed on MECs.

Results

There were 16 MECs; 62.5% were MAML2 rearranged. For the low-, intermediate-, and high-grade MECs, the rate of rearrangement was 83.3%, 100%, and 28.6%, respectively. Both the oncocytic and Warthin-like MECs were MAML2 rearranged. For the classic and nonclassified MECs without MAML2 rearrangement, non-keratinized squamoid cells and distinctive mucinous cells were essential diagnostic criteria. On survival analysis, all the disease progression occurred in high-grade MECs (p = 0.038). Nine cases were diagnosed as non-MECs: pleomorphic adenoma with mucinous metaplasia showed no ex-capsular involvement; metaplastic Warthin tumor appeared with overt keratinization and residual oncocytic bilayered epithelium; mix squamous cell and glandular papilloma showed an endobronchial papillary growing pattern; adenosquamous carcinoma was accompanied by squamous carcinoma in situ of the overlying mucosa. All the non-MECs were negative for MAML2 rearrangement.

Conclusion

The application of combining MAML2 rearrangement and histological characteristics is helpful in the differential diagnosis between MEC and other tumors with mucinous components.

Adenosquamous Carcinomas and Mucinous Adenocarcinoma of the Minor Salivary Glands: Immunohistochemical and Molecular Insights

There is confusion about the diagnosis, histogenesis and taxonomical efforts regarding adenosquamous carcinomas (ASCs) and mucinous adenocarcinomas (MACs), especially with calls for reconsidering the nature of high-grade mucoepidermoid carcinoma (MEC). This study aims to compare the genetic profiles of ASCs and MACs that have been previously reported in the literature and investigate if either ASC or MAC is closer in genetic mutations to high-grade MEC. Systematic searches in the NCBI, Web of Science, and Scopus databases were performed between January 2000 and August 2022. The retrieved genetic mutations were processed and annotated. Protein–protein network analysis was conducted for each neoplasm. The results were viewed and discussed in terms of molecular oncogenesis of ASCs and MACs at different topographies. Molecular profile mapping was conducted by annotating all the retrieved genes for each neoplasm using genetic network analysis (Cystoscape software program). The genetic profile of each lesion was compared to that of high-grade MEC. To conclude, both genetic profiles do not tend to intersect specifically with high-grade MEC, except for the generic mutations commonly detected in all high-grade head and neck tumors. However, the availability of data on the molecular profile of each lesion limits the generalizability of the findings of this study.

Adenosquamous Carcinoma with the Acantholytic Feature in the Oral Cavity: A Case Report and Comprehensive Literature Review

Adenosquamous carcinoma (ASC) is an aggressive subtype of squamous cell carcinoma (SCC). Due to its poor prognosis, a precise pathological diagnosis of ASC is essential but challenging because its pathological criteria are still unclear. Here, we present a rare case of oral ASC accompanied by acantholytic features. The tumor was raised in the mandibular gingiva and recurred locally approximately 13 months after the initial surgery with cervical lymph node metastasis. Pathological specimens of the primary lesion showed acantholysis in a large area of the SCC. Mucous cells, the characteristic finding indicating glandular differentiation, were imperceptible in the initial surgical specimen but increased in the locally recurrent and metastatic lymph node specimens. In a comprehensive literature review of oral ASC cases, the present case was the only case of ASC with acantholytic features. We reconfirmed that ASC has poor prognoses, such as low 5-year overall survival and disease-free survival, high locoregional recurrence, and high distant metastasis rates. A precise diagnosis of ASC is required for estimating prognosis and undergoing close follow-up, even if the adenocarcinomatous component is limited to a small area in the lesion.

Mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma (ASC), the same or different entities?

Mucoepidermoid carcinoma (MEC) and adenosquamous carcinoma (ASC) have overlapping histopathological appearances and sites of occurrence, which may cause diagnostic difficulty impacting subsequent treatment. We conducted a systematic review of the scientific literature to determine whether molecular alterations were sufficiently different in MEC and ASC to aid in classifying the two entities. We searched Medline, Embase and Web of Science for studies reporting molecular determinations of ASC and/or MEC and screened retrieved records for eligibility. Two independent researchers reviewed included studies, assessed methodological quality and extracted data. Of 8623 identified records, 128 articles were included for analysis: 5 which compared the two tumors in the same investigation using the same methods and 123 which examined the tumors separately. All articles, except one were case series of moderate to poor methodological quality. The 5 publications examining both tumors showed that 52/88 (59%) MEC and 0% of 110 ASC had rearrangement of the MAML2 gene as detected by FISH and/or RT-PCR, but did not investigate other genes. In the entire series MEC had MAML2 gene rearrangement in 1337/2009 (66.6%) of tumors studied. The articles examining tumors separately found that MEC had mutations in EGFR (11/329 cases, 3.3%), KRAS (11/266, 4.1%) and ERBB2 (9/126, 7.1%) compared with ASC that had mutations in EGFR (660/1705, 38.7%), KRAS (143/625, 22.9%) and ERBB2 (6/196, 3.1%). The highest level of recurrent mutations was in pancreatic ASC where (108/126, 85.7%) reported mutations in KRAS. The EGFR mutations in ASC were similar in number and kind to those in lung adenocarcinoma. By standards of systematic review methodology and despite the large number of retrieved studies, we did not find adequate evidence for a distinctive molecular profile of either MEC or ASC that could definitively aid in its classification, especially in histologically difficult cases that are negative for MAML2 rearrangement. The case series included in this review indicate the relevance of MAML2 rearrangement to support the diagnosis of MEC, findings that should be confirmed by additional research with adequate study design.

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.

Development of head and neck pathology in Europe

This review gives a brief history of the development of head and neck pathology in Europe from a humble beginning in the 1930s to the explosive activities the last 15 years. During the decades before the introduction of immunohistochemistry in the 1980s, head and neck pathology grew as a subspeciality in many European countries. In the late 1940s, the Institute of Laryngology and Otology with its own pathology laboratory was founded in London, and in 1964 the World Health Organization (WHO) International Reference Centre for the Histological Classification of Salivary Tumours was established at the Bland-Sutton Institute of Pathology, also in London. International collaboration, and very much so in Europe, led to the publication of the first WHO Classification of Salivary Gland Tumours in 1972. In the 1960s, a salivary gland register was organised in Hamburg and in Cologne the microlaryngoscopy was invented enabling microscopic endoscopic examination and rather shortly afterwards a carbon dioxide laser attached to the microscope became established and laryngeal lesions could be treated by laser vaporisation. During the last three decades, the use of immunohistochemistry supplemented with cytogenetic and refined molecular techniques has greatly facilitated the pathological diagnostics of head and neck lesions and has had a huge impact on research. Collaboration between different European centres has drastically increased partly due to establishment of scientific societies such as the Head and Neck Working Group (HNWG) within the European Society of Pathology and the International Head and Neck Scientific Group (IHNSG). A very large number of European pathologists have contributed to the 2nd, 3rd and 4th WHO books, and are involved in the upcoming 5th edition. Accredited educational meetings and courses are nowadays regularly arranged in Europe. Numerous textbooks on head and neck pathology have been written and edited by European pathologists. The increased collaboration has created larger series of tumours for research and new entities, mainly defined by their genetic abnormalities, are continuously emerging from Europe, particularly regarding salivary gland neoplasms and "undifferentiated" sinonasal tumours. These findings have led to a better and more precise classification and open the possibilities for new treatment strategies.

Aggressive squamous cell carcinoma of the cranium of a dog

BACKGROUND

The authors report a case of keratinized squamous cell carcinoma (SCC) in a 14-year-old dog with extensive cranial bone invasion. To our knowledge, this is the first description of such a case of cranial keratinized SCC with aggressive generalized osteolysis described in a dog.

CASE PRESENTATION

The 14-year-old dog was referred for radiological examination with suspicion of head trauma with clinical signs of head deformation, exophthalmos and nasal discharge. The skull radiographs showed a large osteolytic defect of the frontal bone and parietal bone in the region of the external sagittal crest. Findings from the skull CT scan included generalized osteolysis in the region of parietal bone, frontal bones, maxilla on the right side and the nasal bone including the dorsal nasal concha. In the area of bone loss, new soft tissue formation with multifocal foci of mineralization was visible. The ultrasound examination revealed hypoechogenic changes with hyperechoic foci consistent with mineralization and poor vascularization. The brain and ocular structures were without visible changes. Fine needle aspiration cytology (FNAC) was performed, and squamous cell carcinoma was suspected. After 3 months, the re-presented to the clinic. The dog became progressively listless, his appetite was decreased, and he became acutely blind. Follow-up skull CT scan revealed significant osteolysis, which affected a significant aspect of the cranium. All bone defects had been replaced by new 3.5 cm-thick soft tissue formations with multifocal small 1-2 mm areas of mineralization. There was no evidence of metastasis. Histological examination confirmed the suspicion of squamous cell carcinoma.

CONCLUSIONS

This paper is the first report of cranial SCC in a dog causing extensive bone osteolysis. The lesions in this dog originated from the frontal and parietal bones including frontal sinuses. There are variants of tumors that arise from squamous epithelium or resemble SCC in the skull. These examples include adenosquamous carcinoma and proliferating trichilemmal tumours. In addition, there is possible malignant transformation caused by papilloma viruses. In the veterinary literature, there is only one similar description of adenosquamous carcinoma in a cat with similar clinical manifestations. It is justified to suspect a process of neoplastic epithelial origin in all cases of aggressive and extensive skull bone lysis. This issue should be subject to further investigation.

A population-based analysis of adenosquamous carcinoma of the salivary gland

BACKGROUND

Adenosquamous carcinoma (ASC) of the salivary gland is a rare malignancy, and the characteristics and prognosis of this disease remain unclear. This study aimed to assess the clinicopathological characteristics of this rare disease and further determine the potential prognostic factors that affect its outcome.

METHODS

Data of patients with ASC of the salivary gland were extracted retrospectively from the Surveillance, Epidemiology, and End Results (SEER) database between 1973 and 2016. The clinicopathological characteristics of these patients were assessed, and prognostic factors were further determined using Cox regression analysis.

RESULTS

A total of 106 patients with ASC of the salivary gland were identified. The mean age at diagnosis was 66.1±14.9 years, with a male-to-female ratio of 1.47. The parotid gland was the most common primary site (N=91; 85.8%). The 1-, 2-, and 5-year overall survival (OS) rates were 71.5%, 55.0%, 41.5%, respectively. The 1-, 2-, and 5-year disease-specific survival (DSS) rates were 80.8%, 72.2%, and 59.2%, respectively. The OS and DSS shortened with increasing tumor stage, regardless of the American Joint Committee on Cancer tumor-node-metastasis stage or SEER historic stage. Surgery was the main treatment option to improve survival, and post-operative radiotherapy could also prolong OS and DSS (both P<0.01). A multivariate Cox regression analysis demonstrated that distant metastases and the use of surgery or radiation were independent prognostic factors for a favorable OS among patients with ASC of the salivary gland, and early stage (T1/T2) and the use of surgery were independent prognostic factors for favorable DSS among the patients with ASC of the salivary gland.

CONCLUSIONS

This is the largest case series on ASC of the salivary gland. Advanced T stage, distant metastases, and the use of surgery and radiation were associated with OS or DSS of this disease.

Adenosquamous carcinoma of the tongue: A case report and an overview of histogenetic concepts

Adenosquamous carcinoma (ASC), a rare variant of squamous cell carcinoma, is an aggressive and highly infiltrating epithelial neoplasm, which has a distinct histomorphological features comprising simultaneous areas of squamous cell carcinoma and adenocarcinoma. Some researchers consider it as a controversial neoplasm, as it may arise from the ducts of the minor salivary gland or from the overlying surface epithelium. In the head-and-neck region, commonly affected sites include paranasal sinuses, larynx and oral cavity. Areas of occurrence in the oral cavity include palate, tonsillar pillar areas, tongue and floor of the mouth. The prognosis of the neoplasm is considered poor due to its early recurrence, local and distant metastasis and low survival rate. This article reports a case of ASC affecting the posterior part of the tongue in a 50-year-old male patient and an overview of its histogenetic concepts.

Adenosquamous carcinoma development as a recurrence of squamous cell carcinoma in the oral floor: A case report

RATIONALE

Oral adenosquamous carcinoma (ASC) is rare and its origins are controversial. We here present a patient with oral ASC that developed after surgery for oral squamous cell carcinoma (SCC).

PATIENT CONCERNS

A 70-year-old man with SCC on the oral floor underwent surgical resection. However, the enlarged ulcer presented on the oral floor 9 month after surgery.

DIAGNOSES

The biopsy of the ulcer revealed a SCC. Imaging examinations detected enhancement of a large lesion expanded to the tongue, but no evidence of regional lymph node or distant metastasis was shown. Based on these results, local recurrence of the cancer was diagnosed (cT4aN0M0).

INTERVENTIONS

The surgery for the recurrent tumor was performed.

OUTCOMES

The pathological examination of the surgical specimen indicated recurrent tumor was ASC. Thus, histopathological and immunohistochemical analyses of both the initial SCC and the subsequent ASC were performed in an attempt to explore the origin of the ASC. As the results, pathological review of both tumors suggested the subsequent ASC was developed from the tumor cells with adenoid phenotype in the initial SCC.

LESSONS

This report suggests that the oral ASC was origin from the oral SCC, which can contribute to new knowledge for pathogenesis of oral cancer.

Adenosquamous Carcinoma of the Tongue

A 51-year-old white female presented with a painful ulcer of the left ventrolateral tongue. An incisional biopsy confirmed a diagnosis of adenosquamous carcinoma. The adenosquamous carcinoma is an uncommon malignant tumor with histopathological features of a squamous carcinoma and an adenocarcinoma. A definitive diagnosis requires histopathological examination of a deep biopsy involving the submucosal tissue. This malignant tumor shows aggressive behavior with early invasive growth and a poor prognosis. The histopathological findings and differential diagnosis of a case of adenosquamous carcinoma of the tongue are discussed.

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.

How phenotype guides management of non-conventional squamous cell carcinomas of the larynx?

Although the majority of laryngeal malignancies are the conventional squamous cell carcinomas (SCC), a wide variety of malignant epithelial tumors can affect the larynx. Current treatment guidelines are designed to guide clinicians in management of conventional laryngeal SCC. Less is known about the biological behavior and responsiveness to therapy and overall outcomes of other malignant epithelial lesions. Because a spectrum of disease biology is represented by these rare phenotypes, an understanding of the basic biology can help direct management to optimize clinical outcome in this group of patients. This review provides a critical analysis of literature relating to the diagnosis, management, and outcome of patients with non-conventional squamous malignant epithelial neoplasms of the larynx. Particular attention is paid to features which are at variance with the conventional SCC and how these impact on management of these rare tumors.

Oral adenosquamous carcinoma: Report of a rare entity with a special insight on its histochemistry

Adenosquamous carcinoma (ASC) of the head and neck (H and N) is an aggressive variant of squamous cell carcinoma (SCC). They are described as SCC subtype with high infiltrative capacity and also presents with dual histomorphology, having both squamous and glandular cell components. ASC of the H and N region is considered as a controversial tumor, as it is similar to salivary gland mucoepidermoid carcinoma. It has been described in a variety of body sites, including uterine cervix, lung and pancreas. ASC rarely develops in the upper aerodigestive tract, particularly in the oral cavity. The affected sites in oral cavity include palate, tonsillar pillar areas and floor of the mouth. To the best of our knowledge in the literature, only 17 cases of ASC in the floor of the mouth have been reported. Hereby, we report an additional case of ASC occurring in the floor of the mouth in a 70-year-old male patient.

Adenosquamous carcinoma of the tongue: clinicopathologic study and review of the literature

Adenosquamous carcinoma (ASC) of the tongue is an uncommon malignant oral neoplasm with mixed glandular and squamous differentiation and a propensity for aggressive clinical behavior. Here, we report a rare case of ASC of the lateral border of the tongue in a 65-year-old Japanese man. The patient was treated by radical operation and remained well for 6 months before developing metastasis of the hilar and pretracheal lymph nodes. Subsequently, the patient was treated with combined chemotherapy (nedaplatin plus docetaxel and S-1 for two cycles, intravenously) and radiotherapy. Radiation therapy of metastatic lymph nodes was performed at a total dose of 60 Gy and was delivered in 2 Gy fractions 5 days/week. The patient is currently tumor free and is being followed up carefully. This article describes a rare case of ASC of the tongue and its conventional histologic, immunohistochemical, and electron microscopic findings, together with a review of the literature. The findings provide important information to better understand the possible clinical and therapeutic approaches for this uncommon tumor of the tongue.

Adenosquamous Carcinoma of the Head and Neck: A Case-Control Study with Conventional Squamous Cell Carcinoma

Adenosquamous carcinoma (AdSC) is considered a rare variant of squamous cell carcinoma (SCC) which is considered to be more clinically aggressive. Data is very limited with very little case matched data on outcomes in the literature. It is also unknown whether the quantity of the adenocarcinoma component affects outcomes. A retrospective case-control study with 23 cases of AdSC and 1137 SCC controls was conducted. Cases were matched by anatomic subsite, treatment, and, for oropharynx, by p16 status. The following variables were adjusted for in the analysis: T classification (T1/T2 vs. T3/T4), N classification (N0-N2a vs. N2b-N3), age, and smoking. The adenocarcinoma component was quantified by the number of high power fields containing glands as low, moderate, or high. AdSCs had a significantly greater risk of disease recurrence but largely, the differences were not statistically significant. The quantity of adenocarcinoma did not correlate with disease recurrence or survival. This case-control study on AdSC shows modestly more clinically aggressive behavior than conventional SCC, even while controlling for p16 status for oropharyngeal cases. Further, it suggests the current definition of AdSC, with no minimum requirement for gland formation, is clinically accurate.

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.

Ciliated Adenosquamous Carcinoma: Expanding the Phenotypic Diversity of Human Papillomavirus-Associated Tumors

This study describes a unique subset of ciliated, human papillomavirus (HPV) related, adenosquamous carcinomas (AsqCA) of the head and neck that in contrast to most AsqCA, often show areas with lower grade cytonuclear features. They are comprised of largely non-keratinizing squamous cell carcinoma components with cystic change, gland formation, mucin production, and cilia in tumor cells. Seven cases of ciliated AsqCA were retrieved. Site distribution was as follows: palatine tonsil--3/7, base of tongue--1/7, and neck (unknown primary site)--3/7. Despite the occasional resemblance to mucoepidermoid carcinoma (MEC), the tumors showed focal keratinizing morphology and atypia, and all tumors were negative for MAML2 rearrangements. Oropharyngeal and neck tumors were uniformly p16 positive and showed punctate staining by in situ hybridization for high risk HPV DNA. There were two distant metastases (lung), and one tumor related death. Thus, ciliated AsqCA are HPV-associated lesions that pose unique pitfalls, closely mimicking MEC and other salivary gland tumors. These tumors add to the list of those which defy the dogma that ciliated epithelium always equates to a benign process.

IMAGING DIAGNOSIS: COMPUTED TOMOGRAPHIC FINDINGS IN A CASE OF ADENOSQUAMOUS CARCINOMA OF THE HEAD AND NECK IN A CAT

A 15-year-old female spayed domestic long-haired cat was referred for trismus, hypersalivation, and bilateral ocular discharge. On examination, the cat showed pain on palpation of the left zygomatic arch, palpable crepitus of the frontal region, and limited retropulsion of both globes. A contrast-enhanced sinonasal computed tomographic study was performed, showing facial distortion and extensive osteolysis of the skull, extending beyond the confines of the sinonasal and paranasal cavities. Additionally, soft tissue and fluid accumulation were observed in the nasal cavities and paranasal sinuses. Postmortem biopsy samples acquired from the calvarium yielded a histologic diagnosis of sinonasal adenosquamous carcinoma, a rare and particularly aggressive neoplasm previously only reported in the esophagus of one cat.

Immunohistochemical and HPV-related features of laryngeal adenosquamous carcinoma

BACKGROUND

Adenosquamous carcinoma (ASC) of the head and neck is a rare malignancy characterized by loco-regional and distant aggressiveness. At histology, ASC reveals two distinct, juxtaposed components, squamous cell carcinoma (SCC), and true adenocarcinoma.

METHODS

The immunohistochemical expression of AE3, CK19 and CAM5.2, and HPV infection was tested in a case of laryngeal ASC.

RESULTS

The patient had no regional lymph node metastases, but developed a recurrence in neck soft tissues shortly after primary radical surgery. The laryngeal surgical specimen had the typical morphological features of ASC. The tumor's squamous and glandular components were both strongly and diffusely immunoreactive for AE3 and CK19, whereas CAM5.2 selectively stained only the gland-like part. We found no high- or low-risk HPV DNA (28 genotypes) in the specimens. The patient underwent salvage extended radical neck dissection and received postoperative radio-chemotherapy. At 4-month follow-up control, neck recurrence was found. Palliative chemotherapy was instituted.

CONCLUSIONS

An accurate histological and immunohistochemical diagnosis is mandatory to differentiate ASC from conventional SCC. Radical surgical excision is recommended for laryngeal ASC. Adjuvant postoperative therapy is administered in most cases, but there are no widely accepted indications for these treatments.

Adenosquamous carcinoma of unknown primary origin: a case report and literature review

BACKGROUND

Adenosquamous carcinoma is a rare variant of semicircular canal that can affect various regions, including the head and neck. Adenosquamous carcinoma is characterised pathologically by the simultaneous presence of distinct areas of semicircular canal and adenocarcinoma, and usually takes an aggressive course with local recurrences, early lymph node metastases and distant disseminations.

CASE

We report a rare case of neck adenosquamous carcinoma of unknown primary origin, which was well-controlled by thorough resection without any other additional therapy.

CONCLUSION

We discuss the diagnosis and treatment of adenosquamous carcinoma along with a review of pertinent literature. We also consider the potential differential diagnosis of branchiogenic carcinoma.

Prognostic features in mucoepidermoid carcinoma of major salivary glands with emphasis on tumour histologic grading

AIMS

To compare the different grading systems of mucoepidermoid carcinoma (MEC) and identify the most reliable and objective histopathologic features predictive of outcome.

METHODS AND RESULTS

Seventy-two cases diagnosed as MEC were subjected to a meticulous histopathologic re-review. 20 of 72 (28%) cases were originally misdiagnosed as MEC including 16 as high grade (HG). Among the 52 confirmed MEC, median follow up (FU) was 59 months. Mitosis (≥4/10 High Power Fields), necrosis, pleomorphism, focal keratinization, desmoplasia, and lymph node metastasis were associated with adverse disease specific survival (DSS) and recurrence free survival (RFS) (P < 0.002). In all grading systems, low and intermediate grade had similar DSS and RFS but much better outcome than HG (P < 0.007). All patients with tumour harboring low mitotic rate and no necrosis did not recur except for one patient with a positive margin. All cases with high mitotic rate and necrosis died or recurred.

CONCLUSIONS

The majority of previously diagnosed HG MEC cases are misclassified. There is no difference in outcome between low and intermediate grade in all grading schemes. Consideration should be given to stratify MEC based on relatively objective criteria such as mitosis and necrosis.

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.

Adenosquamous carcinoma of hypopharynx with intestinal-phenotype

Adenosquamous carcinomas of the head and neck (ADSCs) are rare locally aggressive malignancies characterized by the presence of two distinctive components, a squamous cell carcinoma and an adenocarcinoma. The immunophenotype of the glandular component of ADSCs has only been rarely studied but has been reported as being positive for keratin 7 (CK7) and carcinoembryonic antigen (CEA) and negative for keratin 20 (CK20). Herein, we report a case of an ADSCs of the hypopharynx composed of a superficial squamous cell carcinoma and an adenocarcinoma with an intestinal phenotype. The patient was a 62 year-old male with a T2 N0 M0 squamous cell carcinoma (SCC) of uvula and palate and a T1 N0 M0 of right hypopharynx. The ADSCs of the hypopharynx was composed of a minimally invasive SCC and an adenocarcinoma with tubulo-glandular and cribriform architecture. The neoplastic glands were positive for CK7, CK20, CDX2, CEA and Villin. The patient underwent radiotherapy to both tumors and remains well with no evidence of recurrent disease 19 months after treatment. To the best of our knowledge, this is the first report of an ADSCs of the head and neck with an intestinal phenotype in its glandular component.

Adenosquamous carcinoma of the head and neck: report of 20 cases and review of the literature

PURPOSE

To assess the clinical profile and prognostic factors in patients with adenosquamous carcinoma (ASC) of the head and neck treated by surgery and/or radiation therapy with or without chemotherapy.

METHODS

Data from 20 patients with stage I-II (n = 4), III (n = 5), or IVA (n = 11) head and neck ASC, treated between 1989 and 2010 were collected in a retrospective multicenter Rare Cancer Network study. Surgery was performed in 16 patients. Seventeen patients received combined modality treatment.

RESULTS

After a median follow-up of 15.5 months, 12 patients recurred. The 3-year and median overall survival, disease-free survival (DFS), and loco-regional control were 52% and 39 months, 32% and 12 months, and 47% and 33 months respectively. In multivariate analysis, DFS was negatively influenced by the presence of extracapsular extension and advanced stage.

CONCLUSION

Overall prognosis of locoregionally advanced ASC remains poor. However, early stage ASC patients managed with combined modality treatment may have prolonged DFS.

Adenosquamous carcinoma of the parotid gland

Adenosquamous carcinoma (ASC) is a rare malignant tumor in the head and neck region and usually it occurs as a mucosal carcinoma. The World Health Organization classification1 shows this tumor as a variation of squamous cell carcinoma (SCC), whereas the Armed Forces Institute of Pathology (AFIP) classification2 categorized it as a salivary gland tumor. In the AFIP guidelines, the occurrence of ASC is limited to the minor salivary glands not in the major salivary glands. This article is protected by copyright. All rights reserved.

A clinicopathological and immunohistochemical study of gastric cancer with squamous cell carcinoma components: a clinically aggressive tumor

OBJECTIVE

Adenosquamous carcinoma originating in the stomach is an unusual neoplasm with few existing histological studies. This study was aimed to gain insight into the histogenetic and clinicopathological characteristics of gastric cancer with squamous cell carcinoma (SCC) components.

METHODS

From January 2001 to June 2010 a total of 1735 patients underwent a resection of gastric cancer. Histopathologically, eight patients had adenocarcinoma containing SCC components, in which the proportion of SCC components was above 25% of the total tumor mass in four patients. The immunohistochemical and clinicopathological characteristics of these eight patients were analyzed.

RESULTS

The median survival duration was 22 months. Adenocarcinoma was present at the superficial layer of all tumors and SCC was primarily present at sites with deep invasion. Immunohistochemically, adenocarcinoma components were positive for cytokeratin (CK) 8/18/19 and CK7 in all cases. SCC components were positive for carcinoembryonic antigen and CK7 in more than 60% of patients. Expression patterns of p53 product were identical in both components. SCC components were positive for 34βE12 and adenocarcinoma components were negative for 34βE12 in all patients.

CONCLUSIONS

SCC components are derived from squamous metaplasia in a pre-existing adenocarcinoma. A gastric adenocarcinoma with SCC components is associated with various patterns of metastasis and both SCC and adenocarcinoma components have the potential for metastasis. Gastric cancer with SCC components is a clinically aggressive tumor.

Adenosquamous carcinoma of the lateral oropharyngeal wall

Adenosquamous carcinoma of the head and neck is a rare and aggressive tumor, with fewer than 100 cases reported in the world literature to date. We report a case of adenosquamous carcinoma of the oral pharynx arising as a second primary malignancy in a patient being treated for primary gastric MALT (mucosa-associated lymphoid tissue) lymphoma. We also review the literature to assess current treatment and long-term prognosis of this rare tumor.

Adenosquamous carcinoma of the head and neck: relationship to human papillomavirus and review of the literature

Adenosquamous carcinoma (ADSC) of the head and neck is an aggressive variant of squamous cell carcinoma (SCC). Certain variants of head and neck SCC are human papillomavirus (HPV)-related and have better prognosis. The relationship of HPV to head and neck ADSC has not been investigated. We searched our files for the term "adenosquamous" and head and neck subsites and found cases from 1998 to 2009. The requisite histologic criteria were the presence of SCC combined with distinct gland formation and/or intracellular mucin. DNA in situ hybridization for high-risk HPV, RNA in situ hybridization for high risk HPV E6 and E7 transcripts, and immunohistochemistry for p16 and p53 were performed. The existing literature on ADSC was also reviewed. Of the 18 cases, eight were from the larynx and hypopharynx, four from the oral cavity, three from the oropharynx, and three from the nasal cavity. Three cases (16%) showed both high risk HPV E6 and E7 and p16 expression, one from the nasal cavity and two from the oropharynx. Both oropharyngeal carcinoma patients were alive and disease free at 34 and 103 months, respectively. ADSCs of the head and neck are a heterogeneous group of tumors. A small minority of cases harbor HPV and most of these, particularly those occurring at sites with known high prevalence of HPV, show active viral transcription with detectable E6 and E7 and overexpression of p16. The HPV-related oropharyngeal cases, though rare, appear to do very well clinically, while the remaining cohort of ADSC patients do quite poorly. Head and neck ADSC appears to be a mixed variant that can be further classified according to its HPV status.

Histologic grading and prognostic biomarkers in salivary gland carcinomas

Both the variety and rarity of salivary gland carcinomas pose challenge for using histologic grade and biomarkers to predict outcome. Mucoepidermoid carcinoma is the histologic subtype for which grading is most prognostically and therapeutically relevant. This tumor is graded using standard schemes in a 3-tier manner with the intermediate-grade category shows the most variability between grading systems and thus the most controversy in management. The t(11;19)(q21; p13) MECT1-MAML2 translocation may be an objective marker that can help to further stratify difficult cases. Adenoid cystic carcinomas are graded based on pattern with solid areas correlating with a worse prognosis. Occasionally, adenoid cystic carcinomas may undergo transformation to highly aggressive pleomorphic high-grade carcinomas with frequent nodal metastases. Comparative genomic hybridization has revealed several chromosomal regions (such as 1p32-p36, 6q23-q27) of prognostic interest in adenoid cystic carcinoma. Carcinoma ex-pleomorphic adenoma is actually a category of tumors rather than a single tumor type with both aggressive and indolent versions. These tumors should be further qualified as to type/grade of carcinoma and extent, as intracapsular and minimally invasive tumors behave favorably. Acinic cell carcinomas, although generally considered low grade, can recur, metastasize, or even prove lethal in a significant number of cases suggesting amenability to a grading scheme to separate these biologic groups. Although aggressive histologic parameters (anaplasia, necrosis, and mitoses) are predictive of poor outcome, a standard grading scheme does not yet exists. Acinic cell carcinomas can also undergo high-grade transformation.