Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Soft Tissue Tumors

Angioleiomyoma of the Pterygopalatine Fossa: A Case Report

Angioleiomyoma (ALM) is a benign neoplasm marked by the presence of blood vessels and smooth muscle cells, commonly located within the subcutaneous or deep dermal layers. Its manifestation in the pterygopalatine fossa is infrequent, thereby posing difficulties in its diagnosis and distinction from other benign tumors within the same anatomical site. In the present case study, an ALM originating in the right pterygopalatine fossa of a 44-year-old female patient was investigated. The patient underwent surgical intervention for the vascular smooth muscle tumor, and there has been no recurrence noted during the postoperative monitoring period.

Large atypical lipomatous tumour of the neck with mediastinal extension managed by transcervical excision

Tumours of adipose tissue origin are relatively rare in the head and neck. Here, we report a case of an unfamiliar lipomatous lesion that involved the neck and mediastinum. A nil-comorbid man in his 40s presented with a slowly progressive anterior neck swelling of 3 years, which was diagnosed as lipoma by histopathological sampling. Computed tomography demonstrated the lesion to be involving parapharyngeal and retropharyngeal spaces with mediastinal extension. The lesion was removed by the transcervical approach. The final histology of the excised specimen, with immunohistochemistry for mouse double minute 2 (MDM2) and p16, suggested an atypical lipomatous tumour (ALT). This report accentuates the occurrence of this rare neoplasm in the neck, which often mimics lipoma clinically. Although radiology can demonstrate suggestive features, histology with MDM2 and/or p16 positivity can confirm the diagnosis of ALT as against the lipoma. A successful transcervical excision, despite the deeper extension of the lesion between the critical structures of the neck and mediastinum, demonstrates the non-infiltrating nature of the tumour.

Surgical management of tumors of the cervical spine and craniovertebral junction involving the vertebral artery: A narrative review

BACKGROUND

The vertebral artery (VA) is in close proximity to bony structures, nerves and nerve sheaths of the cervical spine and craniovertebral junction (CVJ). These structures can be sources of tumors that are responsible for displacement, encasement and sometimes invasion of the VA. Removing these tumors while minimizing the risk of vascular injury requires thorough knowledge of the vascular anatomy, risk factors of vascular injury, the relationships of each tumor type with the VA, and the different surgical approaches and techniques that result in the best outcomes in terms of vascular control, tumoral exposure and resection.

OBJECTIVE

To present an overview of preoperative and anatomical considerations, differential diagnoses and various approaches to consider in cases of tumors in close relationship with the VA.

METHOD

A review of recent literature was conducted to examine the anatomy of the VA, the tumors most frequently affecting it, surgical approaches, and the necessary pre-operative preparations for ensuring safe and maximal tumor resection. This review aims to underscore the principles of treatment.

CONCLUSION

Tumors located at the CVJ and the cervical spine intimately involved with the VA, pose a surgical challenge and increase the risk of incomplete removal of the lesion. Detailed knowledge of the patient-specific anatomy and a targeted pre-operative work-up enable optimal planning of surgical approach and management of the VA, thereby reducing surgical risks and improving extent of resection.

Oral Nodular Fasciitis: A Case Report in an Uncommon Location and Review of the Literature

Nodular fasciitis (NF) is a benign, self-limiting condition that is often misdiagnosed due to its resemblance to other lesions. Although NF is common, its occurrence in the oral cavity is rare and particularly challenging for both clinicians and pathologists. To date, no case has been reported in the retromolar area of the oral cavity. A 49-year-old male patient presented with a painless, rapidly growing, firm nodule in the right retromolar area. Histopathological examination revealed spindle cell proliferation with characteristics of NF and immunohistochemical analysis confirmed the diagnosis. The lesion was treated by conservative surgical excision, without recurrence at a one-year follow-up. In the current case, 54 cases of oral nodular fasciitis (ONF) have been documented. The majority of ONF-affected individuals are in their 40s, with a 1:1 male-to-female ratio. The buccal mucosa was the most commonly involved site followed by the tongue and labial mucosa. Histopathologically, the most prominent features were the proliferation of uniform spindle-shaped cells within a myxomatous and/or fibrotic background. A positive smooth muscle actin (SMA) stain was a consistent finding. Complete local excision remains the preferred treatment method, and no recurrences have been reported. This report underscores the importance of considering NF in the differential diagnosis of oral spindle cell lesions and emphasizes the need for a comprehensive evaluation to guide appropriate management.

Challenges in the assessment of epithelial dysplasia in oral lichen planus and oral lichenoid lesion: Inter and intra-observer variability of the WHO criteria and binary system

Background

Assessment of oral epithelial dysplasia is the gold standard for investigating the risk of malignant progression. The World Health Organization (WHO) methods and the binary system have limitations. This study assess the inter- and intra-observer variability of the architectural and cytological criteria and the classification of the presence and degree of epithelial dysplasia in oral lichen planus (OLP) and oral lichenoid lesion (OLL), using both the 2017 WHO criteria and the binary system.

Material and Methods

The sample consisted of 65 biopsies from lesions classified as OLP and OLL according to the American Academy of Oral and Maxillofacial Pathology (AAOMP) criteria. The histological slides were reevaluated by two oral pathologists.

Results

The individual alterations with most inter-observer disagreement were atypical mitotic figures (43.1%), loss of cohesion between epithelial cells (38.5%) and drop shape rete ridges ridges (38.5%). Inter-observer agreement analysis did not show statistically significant agreement regarding the classification of epithelial dysplasia grade by WHO criteria, only regarding the binary system classification (k=0.257; p=0.035). Intra-observer agreement analysis by evaluator 1 showed that the classification of epithelial dysplasia grade according to both methods had statistically significant agreement (k=0.546; p=0.004, k=0.861; p<0.001). Considering evaluator 2, only the evaluation of the WHO system classification showed statistically significant agreement (k=0.593; p=0.010).

Conclusions

The evaluation of epithelial dysplasia is subjective and focal changes and inflammatory infiltrate, characteristic of OLP and OLL, can increase the degree of disagreement among evaluators. The binary system presents better inter-observer agreement, while the WHO system presents better intra-observer agreement. Key words:Oral lichen planus, oral lichenoid lesion, oral lichenoid disease, dysplasia, inter-observer variation.

Comprehensive molecular profile of primary cutaneous epithelioid rhabdomyosarcoma: A tumor genomically and molecularly related to malignant melanoma

The histogenesis of the rare primary cutaneous epithelioid rhabdomyosarcoma (PCERMS) remains unclear, with the morphological and immunophenotypic appearance of a rhabdomyosarcoma but a genomic profile consistent with sarcomatoid undifferentiated malignant melanoma (SUMM). Here, we provide comprehensive clinical, histopathological, and genomic analysis of a putative PCERMS presenting in an elderly patient. Histopathologic examination revealed an ulcerative tumefactive lesion with diffuse replacement of the dermis by sheets of malignant epithelioid cells with a rhabdoid appearance. By immunohistochemistry, the tumor cells were strongly and diffusely positive for desmin and myogenin. Comprehensive genomic analysis with a 542 gene DNA-based sequencing panel revealed likely biallelic NF1 inactivation (mutation and deletion), TERT promoter mutation, and a high tumor mutation burden (>100 mutations/mB) with features of a UV-mutational signature, which are all genomic features that can be seen in undifferentiated malignant melanoma. This case provides evidence of a close relationship at a molecular level between PCERMS and SUMM. Molecular genomic characterization of a larger cohort of PCERMS is warranted for further elucidation.

Low-Grade Myofibroblastic Sarcoma of the Oral and Maxillofacial Region: An International Clinicopathologic Study of 13 Cases and Literature Review

Low-grade myofibroblastic sarcoma (LGMS) represents an atypical tumor composed of myofibroblasts with a variety of histological patterns and with a high tendency to local recurrence and a low probability of distant metastases. LGMS has predilection for the head and neck regions, especially the oral cavity. This study aimed to report 13 new cases of LGMS arising in the oral and maxillofacial region. This study included LGMS cases from five oral and maxillofacial pathology laboratories in four different countries (Brazil, Peru, Guatemala, and South Africa). Their clinical, radiographic, histopathological, and immunohistochemical findings were evaluated. In this current international case series, most patients were females with a mean age of 38.7 years, and commonly presenting a nodular lesion in maxilla. Microscopically, all cases showed a neoplasm formed by oval to spindle cells in a fibrous stroma with myxoid and dense areas, some atypical mitoses, and prominent nucleoli. The immunohistochemical panel showed positivity for smooth muscle actin (12 of 13 cases), HHF35 (2 of 4 cases), β-catenin (3 of 5 cases), desmin (3 of 11 cases), and Ki-67 (range from 5 to 50%). H-caldesmon was negative for all cases. The diagnosis of LGMS was confirmed in all cases. LGMS shows predominance in young adults, with a slight predilection for the female sex, and maxillary region. LGMS should be a differential diagnosis of myofibroblastic lesions that show a proliferation of spindle cells in a fibrous stroma with myxoid and dense areas and some atypical mitoses, supporting the diagnosis with a complementary immunohistochemical study. Complete surgical excision with clear margins is the treatment of choice. However, long-term follow-up information is required before definitive conclusions can be drawn regarding the incidence of recurrence and the possibility of metastasis.

Human papillomavirus expression in relation to biological behavior, Ki-67 proliferative marker, and P53 prognostic marker in Schneiderian papilloma

Various malignant and benign tumors can arise in the sinonasal cavity, including inverted papilloma (IP), a benign neoplasm with unique clinical characteristics. However, the mechanisms involved in the recurrence, occurrence, and malignant transformation of IP remain debatable. This study aimed to investigate the impact of human papillomavirus (HPV) infections on IP by comparing the number of infections in cases with epithelial tissue dysplasia and explore the predictive role of proliferative and prognostic markers in dysplasia. Tissue blocks from 35 cases of sinonasal papilloma, collected between 2015 and 2021 from the laboratory archives of the Medical City of Ghazi Al-Hererri Hospital in Baghdad, Iraq, were immunohistochemically stained with monoclonal antibodies (mAbs) to detect Ki-67 and p53. A quantitative immunohistochemical analysis was conducted to analyze the results. Polymerase chain reaction (PCR) was performed to detect HPV genotypes 16/18 and 6/11 in the tissues. There was an insignificant increase in Ki-67 and p53 expression in inverted papillomas with dysplasia. HPV11 was the most prevalent genotype in 34.3% of the patients, followed by HPV16 and HPV18 in 31.4% of the patients for each virus. The least common virus detected was human papillomavirus 6 (8.6%), which did not show any significant association with the degree of dysplasia. Viral detection proliferation and apoptosis had no impact on tumor dysplasia amongst all the patients, showing no relationship with the evaluated cases.

[Sinonasal neoplasms: Update from the WHO 2022]

The pathology of poorly differentiated sinonasal malignancies has undergone a dynamic evolution during the last decade, resulting in a refined, mostly genetically or etiologically oriented classification of neoplasms in the historical spectrum of sinonasal undifferentiated carcinoma (NUT carcinoma, SWI-/SNF-deficient carcinomas, and others). Moreover, some new entities have been established, while others could be further delineated and better characterized. A highlight of the new classification is the inclusion of SWI/SNF (SMARCB1 or SMARCA4)-deficient carcinomas into a separate category. In addition, carcinomas with DEK::AFF2 fusions have been included as a provisional entity in the spectrum of nonkeratinizing squamous cell carcinoma. This review addresses the major changes in the classification of sinonasal tract neoplasms in the new WHO classification.

[Rare cancers of the head and neck on behalf of the REFCOR, part 2]

Among the 16,000 new cases of malignant tumors of the head and neck diagnosed in France each year, 10% are not conventional squamous cell carcinomas. These so-called rare cancers are distinguished by their presentation and patterns of failure, which is important to recognize in order to offer specific adapted management and maximize the chances of tumor control. These cancers can be rare by their histology as well as their anatomical location when arising from the paranasal sinuses, salivary glands and ear. The management of these heterogeneous rare diseases of complex treatment has considerably been structured over the last 15 years, in particular via the French ENT Cancer Expertise Network (REFCOR) and international networks and registries (EURACAN, etc.). Structuration also favors research with identification of new entities and setting up of specific therapeutic trials. A first article (part 1) discusses the diagnostic and therapeutic specificities of these rare cancers, and develops the recommendations of the REFCOR concerning rare epithelial tumors, i.e., salivary tumors, sinonasal tumors, variants of conventional squamous cell carcinomas, neuroendocrine carcinomas, malignant odontogenic tumors, and ear tumors. This second article (part 2) is focused on non-epithelial tumors (sarcomas, mucosal melanomas, lymphomas, tumors of uncertain or undetermined malignancy) and describes the organization and missions of the REFCOR.

Clinicopathological and Molecular Characteristics of Intraosseous Rhabdomyosarcoma Involving Head and Neck Region: A Systematic Review and Meta-Analysis

Rhabdomyosarcoma with TFCP2 rearrangement is a newly introduced spindle cell neoplasm showing predilection for craniofacial bones exhibiting highly aggressive nature and poor prognosis. Therefore, an attempt was made to delineate the entity for improved understanding and treatment outcomes through comprehensive analysis of the clinicopathological and molecular characteristics. An electronic search was carried out using MEDLINE by PubMed, Scopus, Google scholar, Cochrane library, and EMBASE databases. Original articles and case reports involving intraosseous rhabdomyosarcoma arising in head and neck region with TFCP2 fusion were included. Data were compiled and risk of bias was analyzed using JBI tool. Thirteen eligible articles were included for the quantitative analysis, which revealed 33 cases with TFCP2 fusion. Majority of the affected individuals were females (58%) with mandible being the common site. Most of the patients died within few months after diagnosis demonstrating a low mean survival rate (30 months). Odds ratio, overall survival and disease-free survival were calculated and analyzed statistically concluding that intraosseous rhabdomyosarcomas harboring TFCP2 fusion are found to be novel and dreadful neoplasms. The predilection for young age with poor prognosis exhibited by these lesions demand early diagnosis and specific treatment planning to curtail mortality.