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

Distant metastasis in head and neck squamous cell carcinoma variants: A population-based study

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) with distant metastasis (DM) has poor prognosis. HNSCC has several histological variants with varying characteristics. We investigated the DM rates and prognoses of patients with DM among the HNSCC variants.

METHODS

We obtained data from 54 722 cases using the Surveillance, Epidemiology, and End Results database. Odds ratios (ORs) for DM and hazard ratios (HRs) for overall survival (OS) were estimated using a logistic regression model and a Cox proportional hazard model, respectively.

RESULTS

DM rate was the lowest in verrucous carcinoma and the highest in basaloid squamous cell carcinoma (BSCC) (0.2% and 9.4%, respectively). ORs for DM were 3.63 for adenosquamous carcinoma, 6.80 for BSCC, and 3.91 for spindle cell carcinoma (SpCC). SpCC was significantly associated with a poor OS (HR, 1.61).

CONCLUSIONS

DM rates differed among the HNSCC variants. The prognosis of metastatic SpCC is worse than that of other metastatic HNSCCs.

CYLD mutation characterizes a subset of HPV-positive head and neck squamous cell carcinomas with distinctive genomics and frequent cylindroma-like histologic features

Mutations in the tumor suppressor CYLD, known to be causative of cylindromas, were recently described in a subset of high-risk (hr) HPV-positive head and neck squamous cell carcinomas (HNSCC). Pathologic and genetic characterization of these CYLD-mutant carcinomas, however, remains limited. Here, we investigated whether CYLD mutations characterize a histopathologically and genomically distinct subset of hrHPV-positive HNSCC. Comprehensive genomic profiling via hybrid capture-based DNA sequencing was performed on 703 consecutive head and neck carcinomas with hrHPV sequences, identifying 148 unique cases (21%) harboring CYLD mutations. Clinical data, pathology reports, and histopathology were reviewed. CYLD mutations included homozygous deletions (n = 61/148; 41%), truncations (n = 52; 35%), missense (n = 26; 18%) and splice-site (n = 9; 6%) mutations, and in-frame deletion (n = 1; 1%). Among hrHPV-positive HNSCC, the CYLD-mutant cohort showed substantially lower tumor mutational burden than CYLD-wildtype cases (n = 555) (median 2.6 vs. 4.4 mut/Mb, p < 0.00001) and less frequent alterations in PIK3CA (11% vs. 34%, p < 0.0001), KMT2D (1% vs. 16%, p < 0.0001), and FBXW7 (3% vs. 11%, p = 0.0018). Male predominance (94% vs. 87%), median age (58 vs. 60 years), and detection of HPV16 (95% vs. 89%) were similar. On available histopathology, 70% of CYLD-mutant HNSCC (98/141 cases) contained hyalinized material, consistent with basement membrane inclusions, within crowded aggregates of tumor cells. Only 7% of CYLD-wildtype cases demonstrated this distinctive pattern (p < 0.0001). Histopathologic patterns of CYLD-mutant HNSCC lacking basement membrane inclusions included nonkeratinizing (n = 22, 16%), predominantly nonkeratinizing (nonkeratinizing SCC with focal maturation; n = 10, 7%), and keratinizing (n = 11, 8%) patterns. The latter two groups showed significantly higher frequency of PTEN alterations compared with other CYLD-mutant cases (38% [8/21] vs. 7% [8/120], p = 0.0004). Within our cohort of hrHPV-positive HNSCCs, CYLD mutations were frequent (21%) and demonstrated distinctive clinical, histopathologic, and genomic features that may inform future study of prognosis and treatment.

Revisiting a rare disease: Oral cavity basaloid squamous cell carcinoma at a high-volume tertiary center

OBJECTIVES

Rare diseases are often poorly understood, and this study sought to investigate the incidence of a rare disease entity, basaloid squamous cell carcinoma (BSCC) of the oral cavity (OC) at a tertiary care medical center and to assess its clinical outcomes.

METHODS

The aim of this study was to collect data in order to better understand how this rare disease progresses. This was a case series of patients with OC BSCC diagnosed between 2001 and 2018.

RESULTS

10 patients with primary OC BSCC were identified. Average age at diagnosis was 58 years (33-71). The median follow-up period was 11 months. Primary sites included oral tongue (n = 4), floor of mouth (n = 4), hard palate (n = 1), and retromolar trigone (n = 1). A majority (60%) of patients had pathologic T3/T4 tumors. All patients underwent primary surgical treatment. There was an overall 60% mortality rate: 2 died from metastasis at 1- and 3-months postop, 2 from unknown causes, 1 from sepsis at 1 month postop, and 1 from metastatic colon cancer. Average survival for those patients who died was 20.7 months. 4 patients were disease-free at the time of publication.

CONCLUSION

There are few studies in the literature that seek to investigate cases of OC BSCC from a single institution. This is the first detailed case series of BSCC from a single American institution. Survival outcomes in our cohort were poor but demonstrate a variable course of disease burden. This study presents unique information regarding specific pathologic characteristics and patient outcomes for this rare disease.

NUT (Nuclear Protein in Testis) Carcinoma: A Report of Two Cases With Different Histopathologic Features

NUT (nuclear protein in testis) carcinoma (NC) is an aggressive carcinoma characterized by rearrangements of the NUT gene on chromosome 15q14. Histologically, it is a poorly differentiated carcinoma composed of monotonous, medium-sized, round cells with scant amphophilic or eosinophilic cytoplasm. Foci of abrupt keratinization are often seen. In this report, we compare the morphology of 2 cases of NC. The first case shows characteristic features of uniform, round epithelioid cells admixed with foci of abrupt keratinization. The second case demonstrates nests of epithelioid-polygonal cells that appear to be loosely cribriform within a mucoid stroma. Although considered rare, the actual incidence of NC may be underestimated, as it is likely that many go undiagnosed because the morphology deviates from what is typical. Our report demonstrates that NC should always be considered in any case of an undifferentiated carcinoma and should not be excluded if typical histologic and immunohistochemical features of squamous differentiation are lacking.

Esophageal adenosquamous carcinoma mimicking acantholytic squamous cell carcinoma

Herein is described a unique case of esophageal cancer mimicking acantholytic squamous cell carcinoma (SCC). The patient succumbed to the disease within one month of diagnosis. Autopsy revealed a 10-cm esophageal tumor, characterized by prominent acantholysis-like areas composed of discohesive cancer cells, along with nested growth of SCC. These discohesive cancer cells focally exhibited pagetoid extension into adjacent esophageal epithelium, comprised ~60% of the esophageal tumor volume and had widely metastasized to the lungs, chest wall, liver, spleen, right adrenal gland, bones and lymph nodes. No metastases of SCC were observed. SCC cells were immunohistochemically positive for keratin 5/6 and E-cadherin and were negative for mucin and carcinoembryonic antigen (CEA). However, the discohesive cancer cells exhibited negativity for keratin 5/6, positivity for mucin and CEA, and diminished or no immunostaining for E-cadherin. Thus, these discohesive cells represented true adenocarcinomatous differentiation rather than acantholytic SCC cells. It was concluded that this tumor was an esophageal adenosquamous carcinoma with 'pseudo'-acantholytic adenocarcinoma components, which should be considered as a rare but distinctive type of aggressive cancer.

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

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

NUT Midline Carcinoma of the Nasal Cavity

Nuclear protein in testis (NUT) midline carcinoma (NMC) is a rare, aggressive, poorly differentiated form of squamous cell carcinoma caused by a chromosomal rearrangement of the NUT gene on chromosome 15. These tumors have a predilection for midline and paramidline structures of the upper aerodigestive tract and mediastinum and can affect patients across a broad age range, including children. In the current example, a 53 year old male presented with a mass originating in the left nasal cavity. The clinical, radiographic, and morphologic features of NMC are discussed.

Cytological features of NUT midline carcinoma arising in sino-nasal tract and parotid gland: Report of two new cases and review of the literature

Nuclear Protein in Testis (NUT) Midline Carcinoma (NMC) represents a recently described, uncommon, high-grade and extremely lethal malignancy mainly occurring in children and young adults. Such tumors are genetically characterized by chromosomal rearrangements of the NUT gene. Cytological description of NUT carcinoma is limited and only seven cases were reported up to date. We show here another two cases studied cytologically with molecular and immunohistochemical confirmation. In both cases smears were hypercellular and composed of isolated or clustered small to medium-sized in size with roundish and oval shape cells. Nuclei were either regular or roundish containing dusty chromatin and prominent nucleoli. Mitotic figures were prominent. Cytoplasm was scant, strongly basophilic. Cell debris, necrosis, and apoptosis were also prominent. One of the cases was studied by FISH and the second case was studied by RT-PCR and BRD4-NUT translocation was found in both cases. Moreover, the clinical evolution was aggressive in both cases with rapid fatal clinical outcome. NUT carcinomas are an underdiagnosed entity which should be taken into consideration when poorly differentiated carcinomas was diagnosed in children or young adults. Cytology material may be successfully used for morphological and molecular diagnosis. Diagn. Cytopathol. 2016;44:753-756. © 2016 Wiley Periodicals, Inc.

Association of Polymorphic Variants of miRNA Processing Genes with Larynx Cancer Risk in a Polish Population

Laryngeal cancer (LC) is one of the most prevalent types of head and neck cancer. An increasing interest has been focused on the role of microRNA (miRNAs) in LC development. The study group consisted of 135 larynx cancer patients and 170 cancer-free individuals. Nine polymorphisms of pre-miRNA processing genes, DROSHA (rs6877842), DGCR8 (rs3757, rs417309, and rs1640299), RAN (rs14035), XPO5 (rs11077), DICER1 (rs13078 and rs3742330) and TARBP2 (rs784567), were performed by TaqMan SNP Genotyping Assay. It was found that the frequency of the GT and the TT polymorphic variants of XPO5 gene were higher in LC patients than in controls (p < 0.0001 and p = 0.000183, resp.). In turn, the frequency of the CT genotype of RAN gene was higher in controls than in LC patients (p < 0.0001). The TT and the AG of DICER1 gene (p = 0.034697 for rs13078 and p = 0.0004 for rs3742330) as well as the AG and the GG genotypes of TARBP2 gene (p = 0.008335 and p < 0.0001, resp.) were associated with higher risk of LC occurrence. Our data suggested that polymorphisms of miRNA processing genes might be useful as predictive factors for the LC development.