Immunohistochemical and genetic analysis of respiratory epithelial adenomatoid hamartomas and seromucinous hamartomas: are they precursor lesions to sinonasal low-grade tubulopapillary adenocarcinomas?

Sinonasal seromucinous hamartoma: a single institution case series combined with a narrative review of the literature

PURPOSE

This study aimed to investigate the clinical and histopathological characteristics of sinonasal seromucinous hamartomas (SHs).

METHODS

Eight patients with sinonasal SH and treated at a tertiary hospital between November 2005 and September 2023 were included. Additionally, a systematic review of published articles was conducted, analyzing 48 cases of SH described in the literature.

RESULTS

Among the eight patients treated at our institution, tumors originated from the posterior nasal cavity in four patients and middle turbinate and middle meatus were the primary origin in two patients each. Coexistence of inflammatory nasal polyps (NPs) was observed in four cases. Histopathologically, four patients exhibited focal respiratory epithelial adenomatoid hamartoma (REAH) features, and low-grade dysplasia was found in one patient. A combined analysis with previous literature revealed that 46.3% of all cases originated in the anterior nasal cavity. The proportions of cases accompanied by NPs and those with focal REAH features were 20.5% and 39.1%, respectively. Additionally, the frequencies of cases exhibiting dysplastic features (5.4%) and recurrence (2.1%) were low. Remarkably, tumors originating from the anterior region tended to have a higher frequency of dysplasia than those originating from the posterior region, although this difference was not statistically significant (p = 0.0996).

CONCLUSION

Patients with sinonasal SH showed favorable treatment outcomes following surgical resection. Focal REAH features and accompanying NPs were frequently observed. A substantial proportion of cases originate in the anterior nasal cavity, and these tumors may exhibit a high tendency for dysplasia.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors

BACKGROUND

Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field.

METHODS

In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication.

RESULTS

The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention.

CONCLUSION

As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Sinonasal Hamartoma and Chronic Laryngeal Edema Causing Severe Dyspnea

Background

Sinonasal hamartomas, according to the 5th edition of the World Health Organisation classification of head and neck tumours are divided into respiratory epithelial adenomatoid hamartoma (REAH), seromucinous hamartoma and chondromesenchymal hamartoma. Seromucinous hamartoma are benign proliferations of small eosinophilic glands surrounded by fibrous stroma and cuboidal cells. Hamartomas of the nasal cavity and paranasal sinuses are rare entities, clinically presenting as sinonasal polyposis.

Case Presentation

A 79- year-old female patient was referred to our emergency room due to severe dyspnea. Anterior rhinoscopy revealed unilateral greyish polypoid mass obstructing the middle, inferior and common nasal meatus. Systemic corticosteroids and oxygen therapy were administered under observation. Computerized tomographic imaging of the paranasal sinuses with contrast on all three planes showed an opacified polypoid mass in all meatus and the maxillary, anterior ethmoidal and sphenoidal sinus posteriorly extending to the choanae. On the coronal plane a widening of the olfactory clefts about 12 mm was described. FESS visualized that the polypoid mass originated from the posterior septum and extended to all meatus anteriorly and to the choanae posteriorly. The polypoid lesion was endoscopically completely excised. Histopathological analysis revealed a seromucinous hamartoma.

Conclusion

Seromucinous hamartoma are rare benign tumors of the sinonasal region with potential of malignant alteration. Unfortunately, they share symptoms and clinical appearance with other benign conditions of the sinonasal region. Therefore, it is even more important to consider them as a differential diagnose.

Nasal Respiratory Epithelial Adenomatoid Hamartoma: Three Case Reports and Review of the Literature

Hamartomas, as non-true tumors, are commonly found in the lungs, digestive tract, and kidneys, and there are few clinical reports on nasal cases. Nasal histiocytosis accompanied by lymphatic lesions is a common feature of nasal hamartoma. Three patients with nasal cavity hamartoma were treated in our department, including 1 male and 2 females, with nasal obstruction or epistaxis. The imaging (computed tomography, magnetic resonance imaging) of 2 patients showed a soft tissue mass in the nasal cavity and no erosion of bone, while in 1 patient, the imaging was inconclusive. The excised material in all patients was found to be a soft mass. The 3 cases showed the same pattern under histological examination, and all 3 patients were diagnosed with nasal cavity respiratory epithelial adenomatoid hamartoma (REAH). Nasal hamartoma is a rare disease with nonspecific clinical manifestations and imaging features and is often misdiagnosed. Only by a better understanding of this disease can the rate of correct clinical diagnosis be improved.

Seromucinous Hamartoma of the Lateral Nasal Wall with Infiltration of the Orbit: A Rare Case Report and Review of the Literature

Seromucinous hamartoma is a rare benign glandular proliferation arising from the respiratory epithelium of the sinonasal tract and nasopharynx. It was described for the first time in 1974 by Baillie and Batsakis. Since then, few cases have been reported in the literature with most of them occurring in the posterior nasal septum. We report the case of a 52-year-old woman that presented to our department with left periorbital edema, pain, and dacryorrhea due to seromucinous hamartoma arising from the left inferior turbinate and extending through the lateral nasal wall into the maxilla, the nasolacrimal duct, and the orbit. Endoscopic medial maxillectomy and endoscopic transnasal orbital tumor resection were performed. The patient remains symptom-free for 16 months, till her most recent follow-up. Seromucinous hamartoma of the nasal cavity is an exceedingly rare diagnosis, especially in the lateral nasal wall. It should be included in the differential diagnosis of nasal tumors. According to the literature review, this is the first case report of seromucinous hamartoma with orbit infiltration. Endonasal endoscopic resection is the treatment of choice.

Low-grade non-intestinal-type sinonasal adenocarcinoma: a histologically distinctive but molecularly heterogeneous entity

Although low-grade non-intestinal-type sinonasal adenocarcinoma (SNAC) is formally a diagnosis of exclusion defined by the absence of salivary or intestinal differentiation, most tumors in this category comprise a distinctive histologic group that are increasingly thought to derive from seromucinous glands. However, the molecular underpinnings of SNAC remain poorly understood, and it is unclear if diverse genetic alterations recently reported in isolated cases should delineate separate subgroups. This study aims to perform comprehensive evaluation of gene fusions and mutations and their histologic correlates in low-grade SNAC to clarify its pathogenesis and classification. We identified 18 non-intestinal-type SNAC that all displayed characteristic tubulopapillary architecture and low-grade cytology, although several cases had other unique histologic features and 3 showed intermixed high-grade areas. Among tumors stained with S100 protein, SOX10, and DOG1, 86% expressed at least one of these seromucinous markers. Of 17 cases with sufficient RNA or DNA available for analysis, likely oncogenic molecular alterations were identified in 76% of cases, most notably including CTNNB1 p.S33F mutations in 2 cases, concomitant BRAF p.V600E and AKT1 p.E17K mutations in 2 cases, and ETV6::NTRK3, PRKAR1A::MET, FN1::NRG1, and DNAJB1::PRKACA fusions in 1 case each. While tumors with most genetic alterations were histologically indistinguishable, cases with CTNNB1 mutations had intermixed squamoid morules and cases with BRAF and AKT1 mutations showed a myoepithelial cell population and prominent papillary to micropapillary architecture. Overall, these findings confirm previous reports of frequent seromucinous differentiation in low-grade SNAC. However, these tumors display striking molecular diversity with involvement of multiple kinase fusions, leading to frequent activation of signaling cascades including the MAPK pathway. While most genetic alterations are not associated with sufficiently distinctive histologic features to suggest separate classification, biphasic tumors with BRAF p.V600E mutations are more unique and may represent a distinctive subgroup.

Towards a Molecular Classification of Sinonasal Carcinomas: Clinical Implications and Opportunities

Simple Summary

In recent years, there have been several molecular and immunohistochemical additions to the pathologic diagnosis of sinonasal malignancies that could facilitate the identification of clinically relevant groups of sinonasal malignancies. Molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this article we review the recent literature on molecular analysis and/or subtyping of sinonasal carcinomas and we discuss the possible clinical implications of a classification of sinonasal tumors based on their molecular features.

Abstract

Sinonasal carcinomas are a heterogeneous group of rare tumors, often with high-grade and/or undifferentiated morphology and aggressive clinical course. In recent years, with increasing molecular testing, unique sinonasal tumor subsets have been identified based on specific genetic alterations, including protein expression, chromosomal translocations, specific gene mutations, or infection by oncogenic viruses. These include, among others, the identification of a subset of sinonasal carcinomas associated with HPV infection, the identification of a subset of squamous cell carcinomas with EGFR alterations, and of rare variants with chromosomal translocations (DEK::AFF2, ETV6::NTRK and others). The group of sinonasal adenocarcinomas remains very heterogeneous at the molecular level, but some recurrent and potentially targetable genetic alterations have been identified. Finally, poorly differentiated and undifferentiated sinonasal carcinomas have undergone a significant refinement of their subtyping, with the identification of several new novel molecular subgroups, such as NUT carcinoma, IDH mutated sinonasal undifferentiated carcinoma and SWI/SNF deficient sinonasal malignancies. Thus, molecular profiling is progressively integrated in the histopathologic classification of sinonasal carcinomas, and it is likely to influence the management of these tumors in the near future. In this review, we summarize the recent developments in the molecular characterization of sinonasal carcinomas and we discuss how these findings are likely to contribute to the classification of this group of rare tumors, with a focus on the potential new opportunities for treatment.

Update from the 5th Edition of the World Health Organization Classification of Head and Neck Tumors: Nasal Cavity, Paranasal Sinuses and Skull Base

The World Health Organization Classification of Head and Neck Tumours recently published the 5th edition. There are new entities, emerging entities, and significant updates to the taxonomy and characterization of tumor and tumor-like lesions, specifically in this article as it relates to nasal cavity, paranasal sinuses and skull base. Importantly, the number of diagnostic entries has been reduced by creating category-specific chapters for soft tissue, hematolymphoid, melanocytic, neuroectodermal, and metastatic tumors. Bone and salivary gland tumors are also not separately reported in the sinonasal tract, but included in the jaw and salivary gland sections, respectively. Repetition of characteristic entities in each anatomic site was also reduced, instead highlighting only the unique features in each anatomic site. Two new entities (SWI/SNF complex-deficient sinonasal carcinomas and HPV-related multiphenotypic sinonasal carcinoma) will be highlighted in this review, with a discussion of several emerging entities. There is a short description of updated information for all 24 diagnostic entities included in this edition to allow the reader a snapshot of current state of knowledge, but to encourage more investigation and further broaden understanding of these diverse and rare entities.

Sinonasal Hamartomas: From Nasal Chondromesenchymal Hamartoma to Respiratory Epithelial Adenomatoid Hamartoma. Report of six Cases and Review of the Literature

Sinonasal hamartomas are uncommon lesions of nasal and sinus cavities. Based on indigenous cellular components and characteristic histologic features, they are further classified into four entities: respiratory epithelial adenomatoid hamartoma (REAH), seromucinous hamartoma (SH), chondro-osseous and respiratory epithelial hamartoma (CORE), and nasal chondromesenchymal hamartoma (NCH). REAH, SH, and CORE are seen in adult patients, while NCH predominantly occurs in newborns and infants. Morphologically REAH and SH are composed of respiratory epithelium and seromucinous glands, CORE is related to REAH but with additional feature of chondroid and/or osseous tissue, and NCH is composed of chondroid and stromal elements but devoid of epithelial component. All four lesions can present as sinonasal mass lesions and with associated obstructive symptoms. Given the rarity of these lesions, diagnosis can be challenging, especially in unusual clinical scenario. In this study, we report six cases of sinonasal hamartoma, including one case of NCH, one case of CORE, two cases of SH, and two cases of REAH. All cases were from adult patients including four men and two women. We also review the literature of the clinical and pathologic features of these rare lesions.

Sinonasal low-grade non-intestinal-type adenocarcinoma: A retrospective analysis and literature review

Sinonasal low-grade non-intestinal-type adenocarcinomas (LG non-ITACs) are uncommon tumors with unclear histogenesis, although they are presumed to arise from seromucous glands or respiratory epithelium. We investigated the clinicopathological and immunohistochemical features of the tumors, with particular attention to the transition area from the normal epithelium to neoplastic cells and concurrent lesions; these features were compared with those of 10 patients with chronic sinusitis, who served as a control group. Seventeen patients with LG non-ITACs (17 tumors) were enrolled in this retrospective study (9 male patients and 8 female patients; mean age, 48 years [range, 16-74 years]). Tumor cells continuous with respiratory epithelium were detected in 10 tumors composed of a single layer of cells with papillary, tubular, or cystic growth pattern. The tumor cells were uniformly cuboidal to columnar and polar. In seven tumors without transition areas discerned, three tumors consisted of polygonal and flat cells with a solid, acinar, micropapillary and cribriform pattern. The others had the same morphology as those with transition areas. The tumor cells were positive for SOX10 (15/17), S100 protein (8/17), and CK7 (17/17). The normal epithelium connected to the respiratory epithelium was the terminal duct in the control group. Except for the lack of p63-positive cells, the immunophenotype and histomorphology of transition areas with LG non-ITACs were similar to those of the continuous areas between the terminal duct and the respiratory epithelium in the control group. LG non-ITACs are seromucinous tumors, some of which may originate from the terminal ducts of seromucinous glands.