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.

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 Glial Hamartoma: A New Type of Sinonasal Hamartomas.

Hamartomas are rare, tumour-forming, benign lesions that have been reported throughout the body that can resemble other malignant entities. Hamartoma subtypes can be distinguished based on their histological features. Sinonasal hamartomas may have presenting symptoms and radiological features that mimic other nasal neoplastic lesions. Therefore, it is essential to diagnose it accurately, as the treatment approaches can range from radical surgeries in malignant cases to a simple excision in hamartoma. In this paper, we report a novel case of sinonasal hamartoma, which demonstrates an unprecedented histological feature of glial tissue with astrocyte-like cells. Furthermore, we present the unconventional presenting symptoms and radiological features seen in this case that mimic the behaviours of nasal inverted papilloma (IP) lesions, thereby highlighting the need for careful investigation of such patients in order to distinguish both glial hamartoma and IP lesions. Concluding that identification of glial hamartoma as a new subtype of sinonasal hamartoma is crucial, as mistaking it for other lesions may subject patients to overly aggressive treatment and potential unnecessary harm.

Nasal and sinonasal tumors formed by atypical adenomatous lesions arising in respiratory epithelial adenomatoid hamartoma/seromucinous hamartoma.

Two benign adenomatous lesions are commonly recognized within the sinonasal tract, namely respiratory epithelial adenomatoid hamartoma (REAH) and seromucinous hamartoma (SH). We present 10 hitherto unrecognized benign polypoid nasal and sinonasal tumoriform lesions having in average 3.6 cm in largest dimension, which are histogenetically related to SH and REAH. In addition to typical structures of REAH and SH, these lesions contained an additional characteristic and slightly atypical adenomatous component, which we termed atypical sinonasal glands arising in SH (ASGSH). ASGSH often produced deep red colored secretion with peripheral clearing similar to that seen in thyroid follicles. In contrast to SH, ASGSH was endowed by both secretory and myoepithelial layers and had mostly angulated shapes with snout-like protrusions into the lumens. Both layers were formed by an irregular, disorganized, and often incomplete cell lining, which had slightly atypical cytological features without mitoses. In 3 cases, ASGSHs revealed sebaceous differentiation, and in 3 cases the stroma produced a well-differentiated cartilage. Neoplastic nature of ASGSH was supported by finding of various mutations as revealed by next generation sequencing in five cases. In two cases each, we found identical mutations in BRAF gene (Val600Glu), and RET gene (Arg912Trp), respectively and in one case FAT1 gene alteration (Pro1665Leu).

A Rare Case of Sinonasal Seromucinous Hamartoma Developing from the Nasal Septum.

A 45-year-old man presented with a history of chronic left nasal congestion. Nasal endoscopy revealed a pedunculated polypoid mass with glandular epithelium surface on the posterior nasal septum. Computed tomography revealed a 25-mm mass-like growth in the left posterior nasal cavity attached to the nasal septum with a stalk. The patient underwent transnasal endoscopic surgery, and the tumor was removed under a block with safety margin. The final pathological diagnosis was sinonasal seromucinous hamartoma (SH). Sinonasal SH is a rare tumor with only 31 reported cases. Transnasal endoscopic surgery is currently the first-line treatment for sinonasal SH. Differential diagnoses of this lesion include inflammatory polyps, respiratory epithelial adenomatoid hamartoma, and adenocarcinoma. Although SH is a benign tumor, its progression to adenocarcinoma has been reported. Therefore, unilateral posterior nasal tumors must be diagnosed precisely.

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.

Analysis of KRAS, BRAF, and EGFR mutational status in respiratory epithelial adenomatoid hamartoma (REAH).

BACKGROUND: Respiratory epithelial adenomatoid hamartoma (REAH) is a sinonasal glandular overgrowth arising from the surface respiratory epithelium and invaginating into the stroma. Clinically, it appears as a polypoid mass that may cause nasal obstruction, anosmia, and epistaxis. The presence of cartilaginous and/or osseous areas move the lesion to a chondro-osseous respiratory epithelial (CORE) hamartoma subtype. Scattered small seromucinous glands may be observed between typical REAH glands and when it is the only feature, it represents seromucinous hamartoma (SH). The molecular pathogenesis of REAH has been poorly explored and remains unclear. Given that KRAS, BRAF, and EGFR mutations have been detected in a variety of sinonasal tumors, we aimed to assess these mutations in REAH and SH. METHODS: Ten REAH (including one CORE subtype), in addition to two SH cases, were Sanger sequenced by standard techniques. The targeted regions included KRAS exons 2-4 (encompassing hotspots codons 12, 13, 61, and 146), BRAF exons 11 and 15 (spanning the V600 codon), and EGFR exons 19 and 20. RESULTS: All REAH and SH samples showed wild-type sequences for KRAS, BRAF, and EGFR genes. CONCLUSION: Our results demonstrate a lack of KRAS, BRAF, or EGFR pathogenic variants with further evaluation of REAH and SH needed to elucidate driver genetic events.

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.

Seromucinous hamartoma of ethmoid sinus in pediatric patient (case report).

INTRODUCTION AND IMPORTANCE: Seromucinous hamartoma is a rare benign glandular proliferation arising from the respiratory epithelium, which was originally described by Baillie and Batsakis in 1974. Since this time, case reports started to be published on SH, as a middle aged and elderly disease, here we report a case of a pediatric patient who found to have SH. PRESENTATION OF THE CASE: 2-year-old girl, brought by her parent with a complain of a mass at the right medial canthal area for one year. CLINICAL DISCUSSION: As this pediatric patient presented with long standing history of right medial canthal area, we made out differential diagnosis list, with keeping congenital midline nasal masses such as nasal glioma, dermoid, and encephalocele at the top of our differentials, followed by inflammatory disease and lacreimal system disease. After bedside clinical assessment and imaging, patient underwent endoscopic sinus surgery for surgical excision, histopathology analysis came as Seromucinous hamartoma. Postoperative course was unremarkable, patient is disease- free for 18 months, till her most recent follow up. With no additional treatment or recurrence. CONCLUSION: This case report indicates that seromucinous hamartoma should always be considered in the differential diagnosis of pediatric sinonasal disease. According to the literature review we did; this is the first case reported in such an age group.

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

Respiratory epithelial adenomatoid hamartoma (REAH) and seromucinous hamartoma (SH) are rare tumor-like lesions of the nasal cavity, paranasal sinuses, and nasopharynx. The pathogenesis of REAH/SH is still unclear. Neoplastic proliferation, chronic mechanical irritation, inflammation, or possible embryological tissue misplacement are speculated as possible mechanisms of their development. Low-grade tubulopapillary adenocarcinoma (LGTA) is a rare variant of nonsalivary, nonintestinal type sinonasal adenocarcinoma. The aim of this study was to evaluate the immunohistochemical and genetic profiles of 10 cases of REAH/SH, with serous, mucinous, and respiratory components evaluated separately and to compare these findings with the features of 9 cases of LGTA. All cases of REAH/SH and LGTA were analyzed immunohistochemically with a cocktail of mucin antigens (MUC1, MUC2, MUC4, MUC5AC, MUC6) and with epithelial (CK7, CK20, CDX2, SATB2) and myoepithelial markers (S100 protein, p63, SOX10). The next-generation sequencing assay was performed using FusionPlex Solid Tumor Kit (ArcherDx) in 10 cases of REAH/SH, and the EGFR-ZNF267 gene fusion was detected in 1 of them. Two female REAH/SH cases were assessed for the presence of clonality. Using the human androgen receptor assay, 1 case was proved to be clonal. The serous component of REAH/SH was positive for CK7/MUC1 and SOX10 similarly to LGTA. Although REAH/SH and LGTA are histopathologically and clinically separate entities, the overlap in their morphological and immunohistochemical profiles suggests that REAH/SH might be a precursor lesion of LGTA.

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.

Update from the 4th Edition of the World Health Organization Classification of Head and Neck Tumours: Tumors of the Nasal Cavity, Paranasal Sinuses and Skull Base.

The sinonasal tract remains an epicenter of a diverse array of neoplasia. This paper discusses changes to the WHO classification system of tumors involving this area. In particular, seromucinous hamartoma, NUT carcinoma, biphenotypic sinonasal sarcoma, HPV-related carcinoma with adenoid cystic features, SMARCB1-deficient carcinoma, and renal cell-like adenocarcinoma are discussed.

Glandular Neoplasia of the Sinonasal Tract.

Glandular lesions that cannot be diagnosed readily as salivary gland tumors occur uncommonly in the upper aerodigestive tract. They occur only with some frequency within the sinonasal tract. Well-characterized lesions at this site include the respiratory epithelial adenomatoid hamartoma, seromucinous hamartoma, and intestinal and non-intestinal-type adenocarcinomas. This article reviews the clinicopathologic features of these fascinating lesions.

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.

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.