Sinonasal seromucinous hamartoma: a review of the literature and a case report with focal myoepithelial cells

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.

Update from the 5th Edition of the WHO Classification of Nasal, Paranasal, and Skull Base Tumors: Imaging Overview with Histopathologic and Genetic Correlation

Sinonasal and skull base tumors are a heterogeneous group of neoplasms with considerable histologic variation and overlapping imaging features. In 2022, the World Health Organization updated the head and neck tumor classification, further emphasizing the importance of molecular data and genetic alterations in sinonasal neoplasms. The changes include the addition of new entities and discussion of emerging entities, as well as changes to the taxonomy and characterization of tumors. The new classification focuses on entities that develop in these sites either exclusively (eg, olfactory neuroblastoma) or most frequently. Another change includes reduction in the number of categories by creating separate category-specific chapters for soft-tissue, hematolymphoid, and neuroectodermal lesions. In this review, we briefly discuss the various categories in the new classification with a more detailed description of the 2 new entities (SWItch/Sucrose Non-Fermentable complex-deficient sinonasal carcinomas and human papillomavirus-related multiphenotypic sinonasal carcinoma). We also highlight the emerging entities including IDH-mutant sinonasal malignancies and DEK-AFF2 carcinoma, presently classified as sinonasal undifferentiated carcinoma and nonkeratinizing squamous cell carcinoma, respectively.

Seromucinous Hamartoma of the Sinonasal Cavity

Benign tumors or malignant neoplasms must be evaluated in patients with unilateral nasal cavity mass lesions. The 3 most prevalent unilateral benign mass lesions in such individuals are nasal polyps (NPs) and inverted papillomas (IPs). Although rare, it should be kept in mind that sinonasal hamartomas can be occasionally diagnosed as well. Among sinonasal hamartomas, respiratory epithelial adenomatoid hamartoma is more prevalent, with seromucinous hamartoma (SMH) being the second most common. Unlike NPs, sinonasal hamartomas are benign tumors with growth potential, which means it should not be undertreated and warrants surgical removal for treatment. However, sinonasal hamartomas do not have local invasion or malignant transformation potential like IPs; hence, it is vital not to overtreat them. Therefore, understanding the histopathology of SMH and thereby establishing proper surgical planning prior to the surgery remains crucial in such cases. Here, we present a successfully treated case of SMH with a distinctive radiographic, gross, and pathological clinical image of SMH.

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.

Transformation from Sinonasal Seromucinous Hamartoma to Adenocarcinoma: A Case Report

OBJECTIVES

Sinonasal hamartomas are benign neoplasms composed of disorganized mature tissue elements. Epithelial variants include respiratory epithelial adenomatoid hamartoma (REAH) and seromucinous hamartoma (SMH). Malignant transformation of REAH is rarely reported; however, the malignant transformation of SMH to adenocarcinoma has not been described. We report the first case of a transformation from SMH to adenocarcinoma.

METHODS

The medical records of a patient presenting with sinonasal SMH with malignant transformation to adenocarcinoma were reviewed. The NCBI database was queried for the literature regarding SMH and malignant transformation of sinonasal hamartomas.

RESULTS

A 39-year-old man presented with a left nasal mass, nasal obstruction, and epistaxis. Computed tomography and magnetic resonance imaging demonstrated a nonaggressive and heterogeneous left nasal mass with involvement of the middle turbinate and posterior ethmoid sinuses. He underwent endoscopic sinus surgery with complete excision of the mass. Pathology revealed SMH with focal areas of transition to low-grade adenocarcinoma characterized by stromal invasion but no bony, perineural, or lymphovascular invasion. Adjuvant treatment was not recommended. Literature review revealed no reported cases of malignant transformation of SMH.

CONCLUSION

We report the first case of malignant transformation of SMH. Patients with SMH must be counseled that there is an extremely rare and potentially unrecognized risk of malignancy that may influence treatment and postoperative monitoring.

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.

Sinonasal cancer: an overview of the emerging subtypes

BACKGROUND

Advances in immunohistochemistry have spearheaded major developments in our understanding and classification of sinonasal tumours. In the last decade, several new distinct histopathological entities of sinonasal cancer have been characterised.

OBJECTIVES

This review aims to provide a clinical update of the major emerging subtypes for the ENT surgeon and an overview of the management strategies available for this heterogeneous group of pathologies.

CONCLUSION

Although rare, knowledge of sinonasal neoplasm subtypes has implications for prognosis, treatment strategies and the development of novel therapeutic targets.

A Rarely Seen Mass of Nasal Cavity: Seromucinous Hamartoma

Seromucinous hamartoma (SH) is a rarely seen benign polypoid mass of the sinonasal tract. Although the most common presentation symptom is nasal obstruction, most of the patients are asymptomatic. In this paper, the authors present an additional case of SH and discuss its differential diagnosis. A 34-year-old male patient presented with progressive nasal obstruction and serous nasal discharge for several months. A well-defined polypoid mass was detected in the left nasal cavity during the endoscopic assessment. Preoperative biopsy was reported as benign polypoid lesion. The mass was resected via transnasal endoscopic approach and final pathological examination was notified as SH.The SH is an uncommon tumor, originates from nasal septum in the most cases and presents as a well-circumscribed polypoid mass. Radiological imaging modalities and biopsy should be performed to distinguish from the sinonasal malignancies. Complete surgical excision is recommended treatment and recurrence is almost never.

Imaging Review of New and Emerging Sinonasal Tumors and Tumor-Like Entities from the Fourth Edition of the World Health Organization Classification of Head and Neck Tumors

The sinonasal tract is an environment diverse with neoplasia. Given the continued discovery of entities generally specific to the sinonasal tract, the fourth edition of the World Health Organization Classification of Head and Neck Tumors was released in 2017. It describes 3 new, well-defined entities and several less-defined, emerging entities. The new entities are seromucinous hamartomas, nuclear protein in testis carcinomas, and biphenotypic sinonasal sarcomas. Emerging entities include human papillomavirus-related sinonasal carcinomas, SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1-deficient sinonasal carcinomas, renal cell-like adenocarcinomas, and chondromesenchymal hamartomas. The literature thus far largely focuses on the pathology of these entities. Our goal in this report was to familiarize radiologists with these new diagnoses and to provide available information regarding their imaging appearances.

Seromucinous Hamartoma of the Nasal Cavity

Seromucinous hamartoma (SMH) is a rare benign epithelial proliferation occurring in the sinonasal tract. The clinical, radiographic, and histologic appearance of SMH may mimic several benign and malignant entities. Presented is a novel case, with a review of the literature focused on potential histologic diagnostic pitfalls.

Sinonasal seromucinous hamartoma

INTRODUCTION

Seromucinous hamartoma (SH) is a rare benign glandular proliferation of the sinonasal tract and nasopharynx. Only few cases have been reported in recent years.

MATERIALS AND METHODS

We performed a retrospective medical record review of seven patients diagnosed with sinonasal SH who underwent endoscopic endonasal surgery.

RESULTS

There were 5 males and 2 females, ranged in age from 40 to 98 years (mean 60 years, SD ± 18.9). Two lesions arise from middle turbinate, two from uncinate process, and 3 (but 4 specimens) from nasal septum. Pathological features revealed a polypoid lesion with submucosal proliferation of seromucinous glands arranged in lobular and haphazard patterns. In immunohistochemical study, the seromucinous glands of SH were reactive for cytokeratin, including CK7, CK19, HMWK, but negative for CK20.

CONCLUSION

Sinonasal SH is a rare diagnosis characterized by a polypoid lesion with a haphazard proliferation of seromucinous glands. The rhinologists should consider it in the differential diagnosis of a polypoid lesion in the nasal cavity.

Olfactory Epithelial Hamartoma: A New Subtype of Sinonasal Hamartoma

Sinonasal epithelial hamartomas occurring in adults are classified as seromucinous hamartoma (SMH) or respiratory epithelial adenomatoid hamartoma (REAH). We describe herein a novel subtype of adult sinonasal hamartoma that contains olfactory epithelium, a histologic feature not previously reported in the literature. Our pathology department database was retrospectively searched for sinonasal hamartomas containing areas of olfactory epithelium. Six relevant cases (3 male and 3 female patients; age, 30 to 77 y) were retrieved, and available pathology slides and clinical and imaging data from patient charts were reviewed. Five of the lesions were unilateral solitary, polypoid, pedunculated masses, 38 to 80 mm in length, lodged in the nasal olfactory cleft. The sixth lesion was associated with bilateral nasal polyposis, and its precise localization was not known. All patients were treated by transnasal endoscopic surgery. None of the 3 patients who had received adequate follow-up evaluation exhibited recurrence. Histologically, all lesions resembled SMH or REAH, with areas of olfactory epithelium comprising olfactory receptors and sustentacular and basal cells. Olfactory epithelium was observed at the lesion surface or in invaginated gland-like structures, and it contained focal aggregates of filamentous cell processes. Some olfactory receptor cells or cell processes were also present in the seromucinous gland component of lesions. Olfactory receptor cells expressed CD56 (neural cell adhesion molecule), and the filamentous aggregates contained CD56, neurofilaments, and synaptophysin. Aside from SMH and REAH, we have described a third subtype of adult sinonasal hamartoma-olfactory epithelial hamartoma-which shares the benign character of the other 2.

Low-Grade Epithelial Proliferations of the Sinonasal Tract

Low-grade epithelial proliferations of the sinonasal tract include Schneiderian papillomas, respiratory epithelial adenomatoid hamartoma, seromucinous hamartoma and low-grade non-intestinal adenocarcinoma. There is considerable overlap in their clinical presentation, endoscopic appearance, and imaging features. Although well-described diagnostic criteria exist, a definitive diagnosis may be difficult to reach on a small biopsy. Schneiderian papillomas are divided into fungiform, inverted, and oncocytic types, each with characteristic clinical and morphological features. The latter two may progress to malignancy. The majority are still considered to be HPV-related. Two lesions are designated as hamartomas, but their pathogenesis remains uncertain, with inflammatory and neoplastic origins proposed. Respiratory epithelial adenomatoid hamartoma is increasingly being recognized for its association with chronic rhinosinusitis and olfactory cleft site of origin. Seromucinous hamartoma has gained attention in recent years and overlaps with both respiratory epithelial adenomatoid hamartoma and low-grade non-intestinal adenocarcinoma. Controversy surrounds their distinction, particularly from low-grade adenocarcinoma. The latter generally is cured by complete excision, with a 26 % risk of recurrence but rare metastases and deaths from disease.

[Respiratory epithelial adenomatoid hamartoma of the nose and nasal sinuses : a rare differential diagnosis of nasal polyposis]

INTRODUCTION

Hamartomas are benign tumor-like lesions resulting from incorrectly differentiated germplasm and can manifest in different organ systems. In the nasal cavity and the sinuses these lesions are rare. Only few data on etiology, epidemiology and clinical significance of these tumors exist to date.

MATERIALS AND METHODS

In a retrospective study, material from patients treated in the Clinic for Otorhinolaryngology, Head and Neck Surgery of the Ulm Military Hospital was screened on the incidence and clinical courses of respiratory epithelial adenomatoid hamartomas (REAH) of the nose and nasal cavity. Furthermore, for cases of REAH, formalin-fixated paraffin-embedded tissue samples were re-evaluated and examined for human papillomavirus (HPV) DNA by PCR.

RESULTS

Tissue samples from 8145 surgical interventions on the nose and nasal sinuses from 2003 to 2012 were included. A total of 22 patients (3 female, 19 male; median age 57.5 years) diagnosed with REAH could be identified. Major complaints were nasal blockage (91 %), sinusitis (82 %), rhinorrhea (36 %) and cephalgia (23 %). Nasal endoscopy showed polyps in 68 % of patients. Native nasal sinus CT scans revealed no indications of REAH. Intraoperatively, hamartomas were found in 12 patients originating from the ethmoid bone, in 8 from the middle meatus or infundibulum and in 2 from the olfactory cleft. Macroscopic and histological examination showed compact lesions sized between 4 and 25 mm in the largest diameter containing homologous tissue, without signs of dysplasia or malignancy. HPV DNA was not identified in any case.

CONCLUSION

REAH of the nasal cavity and sinuses are rare benign local tissue lesions, usually without any autonomous proliferation. Clinical signs and findings correspond to those in polypoid pansinusitis. Only with single-sided or olfactory cleft location might CT scans provide indication of a tumorous lesion. For differentiation from true neoplasms, surgical resection and histopathological clarification is indicated. On the basis of current knowledge, complete surgical resection is adequate therapy.

Respiratory epithelial adenomatoid hamartoma of the nose: an updated review

BACKGROUND

This study was designed to update clinical and imaging features as well as treatment outcomes of the nasal respiratory epithelial adenomatoid hamartoma (REAH). Data sources included case reports, original articles, and reviews published in English or French in PubMed from 1995 to date.

METHODS

Only published articles that met Wenig's histological criteria for the diagnosis of REAH were included.

RESULTS

REAH is not rare and is probably underdiagnosed. It is usually observed in the fifth decade of life with a 3:2 male/female predilection. REAH can be represented in two forms: as an isolated lesion (less frequent) or in association with an inflammatory process (especially nasal polyposis). It was observed in 35-48% of patients undergoing endoscopic endonasal surgery for nasal polyposis. Its origin is found, in most cases, in the olfactory cleft, which is exhibited on computed tomography (CT) scans by widened opacified olfactory clefts without bone erosion. Resection of REAH from the olfactory clefts does not worsen, but instead, can improve the sense of smell after surgery.

CONCLUSION

Looking for REAH on CT scans and during endoscopic examination can lead to its diagnosis and help avoid aggressive surgical procedures and their complications. Endoscopic resection is the treatment of choice. The removal of REAH constitutes a specific surgery on the olfactory clefts, which can improve nasal obstruction as well as sense of smell. Whether REAH can be defined as a hamartoma, an inflammatory reactive process, or a neoplastic lesion remains to be determined.

A Subset of Sinonasal Non-Intestinal Type Adenocarcinomas are Truly Seromucinous Adenocarcinomas: A Morphologic and Immunophenotypic Assessment and Description of a Novel Pitfall

While sinonasal intestinal type adenocarcinoma (ITAC) is defined by an intestinal phenotype, non-intestinal type adenocarcinoma (non-ITAC) is traditionally viewed as a diagnosis of exclusion, despite previous implication of a seromucinous phenotype and similarity to sinonasal seromucinous hamartomas (SSH). We performed a comparison of clinicopathologic and immunophenotypic features of ITAC, non-ITAC and SSH using traditional discriminatory markers and new markers of seromucinous differentiation. Twenty-three non-ITAC, 17 ITAC, and 5 SSH were retrieved (1987-2014). As expected, ITAC occurred predominantly in the nasal cavity in elderly patients (mean age 65 years) with a striking male predilection (15:2). Regardless of grade/subtype, all ITAC were invariably CK20 and CDX2 positive, and many (11/15) showed some CK7 positivity. Non-ITAC occurred in younger individuals (mean age 51 years) with a slight female predilection (male to female ratio: 10:13) and showed diverse morphologic patterns and grades, some with morphologic similarity to SSH. SSH occurred in younger individuals (mean age 33 years). Non-ITAC and SSH were invariably CK7 positive and CK20 negative, however, 4/22 non-ITAC and 2/5 SSH showed squamoid morular metaplasia that aberrantly expressed CDX2 and co-expressed nuclear β-catenin. Markers of seromucinous differentiation (S100, DOG1, and SOX10) were essentially absent in ITAC, but present to varying degrees in the majority of non-ITAC and all SSH. Thus, the term 'seromucinous adenocarcinoma' is the more appropriate designation for non-ITAC. Squamoid morules in non-ITAC and SSH may be an immunophenotypic pitfall given the aberrant CDX2 expression.

Seromucinous hamartoma in the nasal cavity medial to the middle turbinate: report of 2 cases and review of the literature

BACKGROUND

Seromucinous hamartoma, a type of epithelial hamartoma, is a rare benign glandular proliferation of the sinonasal tract and nasopharynx. Herein, we present 2 rare cases of seromucinous hamartoma arising in the nasal cavity medial to the middle turbinate.

METHODS AND RESULTS

This is a case report of 2 patients diagnosed with seromucinous hamartoma of the nasal cavity and a review of the literature.

CONCLUSION

Seromucinous hamartoma of the nasal cavity is an exceedingly rare diagnosis but should be included in the differential diagnosis of a posterior nasal tumor. Most cases arise from the posterior nasal cavity medial to the middle turbinate rather than lateral to the middle turbinate.

Recently described sinonasal tract lesions/neoplasms: considerations for the new world health organization book

Since the publication of the World Health Organization Classification of Head and Neck Tumors (Barnes et al., World Health Organization classification of tumours. Pathology and genetics head and neck tumours, IARC Press, Lyon, pp 10-80, 2001), a number of sinonasal lesions have been more completely described. This manuscript will focus on three such "new" lesions including sero mucinous hamartoma, HPV-related carcinoma with adenoid cystic-like features and low-grade sinonasal sarcoma with neural and myogenic features.