Seromucinous hamartoma is a rare benign glandular lesion of the sinonasal tract that may present significant diagnostic challenges. This case describes a female patient with a previously biopsied nasopharyngeal mass who later presented with recurrent blood expectoration and persistent right-sided aural fullness. Otoscopy and audiologic testing demonstrated middle-ear effusion, moderate-to-severe mixed hearing loss, and a type B tympanogram on the right. Endoscopy revealed a large vascular-appearing nasopharyngeal lesion, while CT demonstrated a 4.6 cm heterogeneously enhancing mass causing Eustachian tube obstruction and complete opacification of the right middle ear and mastoid, with subtle osseous erosion and close contact with the internal carotid artery. A previous biopsy had favored seromucinous hamartoma and was negative for malignancy. The marked clinical radiological and pathologic discordance emphasizes the limitations of small biopsies in large or heterogeneous lesions and the importance of adequate tissue sampling, multidisciplinary correlation, and specialized head-and-neck evaluation. The case also reviews the histopathology, differential diagnosis, evolving molecular concepts, and current management of this uncommon entity.
Table of Contents
1. Introduction
2. Case Presentation
2.1. Historical pathology
2.2. Presentation on December 12, 2024
2.3. Otologic and audiologic evaluation
2.4. Flexible nasopharyngolaryngoscopy
2.5. Radiologic evaluation
2.6. Follow-up and referral
3. Discussion
3.1. Definition, rarity, and anatomic distribution
3.2. Histopathologic Spectrum of Seromucinous Hamartoma
3.3. Immunohistochemical Profile and Diagnostic Limitations
3.4. Relationship Between SH and REAH
3.5. Molecular Findings and the Question of True Neoplasia
3.6. Pathologic Differential Diagnosis
3.7. Pathologic Significance of the Present Case: Clinicoradiologic-Pathologic Discordance
3.8. Otologic Manifestations and Eustachian Tube Obstruction
3.9. Treatment Implications and Follow-up
4. Strengths and Limitations
5. Conclusion
6. Learning Points
7. Suggested Publication Declarations
Objectives & Topics
The primary objective of this work is to present and analyze an exceptional clinical case of a nasopharyngeal seromucinous hamartoma (SH) presenting as a large, locally aggressive-appearing mass, and to explore the clinical, radiological, and histopathological challenges associated with managing substantial diagnostic discordance. The study investigates how clinicians and pathologists must navigate situations where a previous limited biopsy indicates a benign hamartoma while subsequent imaging demonstrates an extensive mass with bone remodeling, deep structure abutment, Eustachian tube obstruction, and internal carotid artery contact.
- Clinical and diagnostic presentation of rare sinonasal seromucinous hamartomas
- Audiologic and otologic consequences of Eustachian tube obstruction secondary to nasopharyngeal masses
- Clinicoradiologic-pathologic discordance and limitations of superficial or small-volume biopsies
- Histopathological, immunohistochemical, and molecular differentiation between SH, REAH, and sinonasal adenocarcinomas
- Surgical considerations, multidisciplinary evaluation, and conservative endoscopic management strategies
Excerpt from the Book
3.2. Histopathologic Spectrum of Seromucinous Hamartoma
Seromucinous hamartoma (SH) is an uncommon benign glandular proliferation of the sinonasal tract whose histopathologic interpretation has evolved considerably since its original description. Baillie and Batsakis first reported the entity in 1974 as a glandular (seromucinous) hamartoma of the nasopharynx, establishing the nasopharyngeal region itself as one of the historically recognized sites of origin [1]. Subsequent clinicopathologic studies demonstrated that SH has a broader morphologic spectrum than initially appreciated [4,5].
A particularly influential contribution was made by Weinreb et al., who characterized seven lesions and emphasized an edematous-to-fibrous stroma containing irregular and haphazard small serous glands, ducts and tubules, variably accompanied by cystically dilated glands and invaginations of respiratory epithelium. Their study also documented focal respiratory epithelial adenomatoid hamartoma (REAH)-like areas, supporting morphologic overlap between these benign glandular proliferations [4].
In conventional SH, the epithelial cells are cytologically bland. Overt destructive invasion, marked nuclear pleomorphism, brisk mitotic activity, necrosis, and unequivocally malignant architectural complexity are not expected. This distinction is important because irregular or crowded glands in a limited biopsy can mimic low-grade glandular neoplasia. Conversely, a small benign-appearing biopsy may not necessarily represent every component of a large or heterogeneous lesion.
Weinreb et al. also highlighted a diagnostically counterintuitive feature: the seromucinous component frequently lacks a demonstrable peripheral myoepithelial/basal cell layer with markers such as p63, CK14, calponin and muscle-specific antigen [4]. Fleming et al. subsequently confirmed the general importance of this pattern while reporting a case with focal myoepithelial cells, illustrating that immunophenotypic findings are not absolutely uniform [5]. Absence of a myoepithelial layer in SH therefore should not, by itself, be interpreted as evidence of invasion.
Chapter Summaries
1. Introduction: Introduces seromucinous hamartoma as a rare benign glandular entity of the sinonasal tract, reviewing its initial description, diagnostic rarity, and the diagnostic challenges posed by clinical and radiologic discordance.
2. Case Presentation: Details a patient presenting with throat bleeding, aural fullness, mixed hearing loss, and a large nasopharyngeal mass on endoscopy and CT, despite a previous biopsy diagnosed as benign seromucinous hamartoma.
3. Discussion: Provides a comprehensive literature review encompassing the anatomical distribution, histopathologic and immunohistochemical spectrum, molecular insights, differential diagnoses, otologic correlates, and surgical management of sinonasal seromucinous hamartomas.
4. Strengths and Limitations: Outlines the strengths of longitudinal clinical, endoscopic, and imaging documentation while transparently acknowledging limitations such as the unavailability of subsequent tertiary-center operative records and biopsy images.
5. Conclusion: Synthesizes core clinical findings, emphasizing that prior benign pathology must be re-evaluated when imaging demonstrates aggressive features, requiring thorough multidisciplinary reconciliation and specialized care.
6. Learning Points: Outlines high-yield clinical takeaways regarding the rarity of SH, its overlap with other glandular lesions, the risks of sampling error, and the necessity of tertiary skull base evaluation for extensive masses.
7. Suggested Publication Declarations: Details the ethical guidelines, consent verifications, privacy protections, and authorship statements necessary for final scientific manuscript publication.
Keywords
seromucinous hamartoma, nasopharynx, sinonasal hamartoma, nasopharyngeal mass, epistaxis, Eustachian tube obstruction, middle-ear effusion, mixed hearing loss, tympanometry, endoscopy, clinicoradiologic discordance, head and neck pathology
Frequently Asked Questions
What is the core subject of this publication?
This publication examines the clinical presentation, diagnostic evaluation, and literature context of a rare nasopharyngeal seromucinous hamartoma that appeared on cross-sectional imaging as a large, locally aggressive mass despite prior benign biopsy findings.
What are the primary thematic areas explored in the document?
The work focuses on head and neck oncology, endoscopic diagnosis, differential histopathology between benign hamartomas and low-grade sinonasal adenocarcinomas, and the audiological implications of Eustachian tube obstruction.
What is the main objective or clinical question addressed?
The study addresses how to evaluate and manage significant discordance between historical benign histology and contemporary radiologic evidence indicating a large, expanding mass abutting critical skull base structures.
Which scientific methods are applied in this work?
The authors employ a single-patient longitudinal case report combined with otoscopic, audiometric, endoscopic, and contrast-enhanced CT evaluations, integrated with a narrative and focused review of current pathological and surgical literature.
What key insights are presented in the main discussion?
The discussion highlights the histopathologic nuances of seromucinous hamartoma, including the lack of a myoepithelial cell layer, diagnostic immunohistochemical markers, potential biopsy sampling errors, and the importance of conservative endoscopic resection.
Which keywords best characterize the publication?
The work is defined by terms such as seromucinous hamartoma, nasopharynx, clinicoradiologic discordance, Eustachian tube obstruction, middle-ear effusion, endoscopy, and head and neck pathology.
Why did the patient experience hearing loss and aural fullness?
The extensive right-sided nasopharyngeal lesion physically obstructed the right Eustachian tube, causing fluid accumulation in the middle ear cavity and mastoid cells, resulting in otitis media with effusion and moderate-to-severe mixed hearing loss.
Why can a biopsy in seromucinous hamartoma lead to diagnostic pitfalls?
A limited superficial biopsy may sample only a small fraction of a large or heterogeneous mass, potentially missing an adjacent neoplasm or, conversely, displaying crowded glands without basal layers that mimic low-grade adenocarcinoma.
What are the recommended management options for seromucinous hamartoma?
When localized and anatomically resectable, the treatment of choice is complete conservative transnasal endoscopic surgical excision without the need for adjuvant radiotherapy or aggressive radical surgery.
- Quote paper
- MD Manuel Medina Suarez (Author), MD Pablo Arango (Author), Manuel Javier Medina Rodriguez (Author), 2026, Nasopharyngeal Seromucinous Hamartoma Presenting as a Large Locally Aggressive-Appearing Mass, Munich, GRIN Verlag, https://www.grin.com/document/1772211
