Respiratory epithelial adenomatoid hamartoma of the bilateral olfactory recesses: a neoplastic mimic?

Respiratory Epithelial Adenomatoid Hamartoma at an Unusual Location: A Case Report and Literature Review

Respiratory epithelial adenomatoid hamartoma (REAH) in the head and neck is a rare benign lesion containing glandular tissue covered with ciliated respiratory epithelium. In the head and neck, REAH of the nasal cavity, paranasal sinuses, and nasopharynx have been reported in literature. Due to rareness of REAH and insufficient knowledge of its imaging features, the diagnosis can be challenging when we encounter a non-specific cystic mass at an uncommon site in the head or neck. Here, we report the case of a pathologically confirmed REAH showing a cystic mass centered at the buccal space (retromaxillary fat pad) with CT and MRI findings.

[Clinical characteristics of nasal respiratory epithelial adenomatoid hamartoma]

〓 Objectives: To analyze the pathological and clinical features of nasal respiratory epithelial adenomatoid hamartoma（REAH）, and summarize the diagnostic points, to improve the experience of diagnosis and treatment. Methods:The clinical data of 16 patients with REAH were analyzed retrospectively. The clinical manifestations, pathological features, imaging features, surgical treatment and prognosis were summarized. Results:16 cases of REAH were studied, 10 cases（62.50%） were associated with sinusitis, 1 case（6.25%） was associated with inverted papilloma, 1 case（6.25%） was associated with hemangioma. 5 cases（31.25%） had a history of nasal sinus surgery, including 1 case with 3 times of nasal sinus surgery, 1 case with 2 times of nasal sinus surgery, 3 cases with 1 time of nasal sinus surgery; 10 cases（62.50%） occurred in the bilateral olfactory cleft, 2 cases（12.50%） in the unilateral olfactory cleft, 3 cases（18.75%） in the unilateral middle turbinate, 1 case（6.25%） in the nasopharynx. All 16 patients were pathologically diagnosed as REAH. In the patients with lesions located in bilateral olfactory fissures, symmetrical widening of olfactory fissures and lateral displacement of middle turbinate were observed on preoperative sinus CT. The average width of bilateral olfactory fissures was （9.9±2.70） mm. The ratio of wide to narrow olfactory cleft was 1.21 ± 0.19. There was no significant difference in Lund-Mackay score between the two sides（P>0.05）. All patients underwent surgery under general anesthesia and nasal endoscopy. The follow-up period ranged from 1 to 66 months, and no recurrence occurred. Conclusion:Preoperative diagnosis of REAH is facilitated by the combination of clinical manifestations and endoscopic and imaging features. Endoscopic complete resection can achieve a good therapeutic effect.

Is Respiratory Epithelial Adenomatoid Hamartoma Related to Central Compartment Atopic Disease?

BACKGROUND

Respiratory epithelial adenomatoid hamartoma (REAH) is a benign lesion of the sinonasal tract that may mimic more concerning pathology. Clinical factors associated with REAH have not been well characterized.

OBJECTIVE

To report our findings on patients with this pathologic diagnosis.

METHODS

A retrospective chart review of patients with REAH between September 2006 and November 2019 was conducted. Data collected included clinical allergic rhinitis and asthma history, additional sinonasal diagnoses, prior sinus surgery, and the location of the REAH within the sinonasal cavity.

RESULTS

Twenty-six patients were identified (53.8% male, mean age 62 years [range, 29-93]). Bilateral REAH occurred in 50%. REAH was located at the superior nasal septum in 84.6% cases, with the remainder identified in sinus contents submitted for pathology, making definitive site uncertain. Concurrent sinonasal inflammatory disorders were identified in 18 patients (69.2%), including chronic rhinosinusitis with nasal polyps-not otherwise specified (6), chronic rhinosinusitis without nasal polyps (4), aspirin-exacerbated respiratory disease (2), allergic fungal rhinosinusitis (1), central compartment atopic disease (5), and IgG4-related sclerosing disease (1). Eight patients had isolated REAH. Adequate allergy records were available for 19 patients, of which 18 of 19 (94.7%) had clinical allergic rhinitis.

CONCLUSIONS

REAH is a benign sinonasal lesion commonly located within the central compartment of the nasal cavity, a site of significant allergen exposure. Affected patients have a high incidence of allergy along with chronic inflammatory conditions. The coexistence of REAH within inflammatory nasal mucosa in a consistent anatomic location, suggests REAH may have a similar etiology to central compartment atopic disease, with resultant respiratory glandular ingrowth within long-standing reactive changes of mucosa derived from ethmoid embryologic origin.

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.

Respiratory Epithelial Adenomatoid Hamartoma (REAH) in the Olfactory Cleft: Often Masked by Bilateral Nasal Polyps

Respiratory epithelial adenomatoid hamartoma (REAH) is a distinct non-neoplastic entity originating from anterior olfactory cleft in the nasal cavity, often going unnoticed. Clinically, REAH presents as unilateral or bilateral nasal polyps. Our aim is to expand the understanding of bilateral REAH associated with nasal polyposis with respect to clinical, radiological and histopathological features for better clinical outcomes. Our analysis includes patients presenting as bilateral nasal polyps, whose CT-PNS showed opacity in olfactory clefts. During endoscopic sinus surgery, the lesions in the olfactory cleft (medial-to-middle turbinate) were identified and the specimens from olfactory cleft and ethmoid sinus cavity were subjected separately to histopathological analysis. Six patients (average age 50 years, 83% male) of bilateral REAH with nasal obstruction of > 3 years were analysed. On nasal endoscopy, the polypoid masses in the olfactory cleft and in the ethmoids did not show any gross differences. However, polypoidal masses from the olfactory cleft bled more during biopsy and excision. Histopathological study of these masses revealed the closely arranged round to oval glands (with few dilated glands) lined by ciliated columnar epithelium in mildly edematous stroma, confirming the presence of REAH. REAH is an often overlooked lesion in the nasal cavity, arising from olfactory cleft. The presence of nasal polyposis obscures this lesion, resulting in under diagnosis. The prompt identification with high index of suspicion by the otorhinolaryngologists helps in accurate histopathological diagnosis thereby improving clinical outcomes.

An atypical presentation of a Respiratory Epithelial Adenomatoid Hamartoma, a case report

Introduction

Respiratory Epithelial Adenomatoid Hamartoma (REAH) is a benign disease that can resemble other malignant entities. Thus, it is essential to diagnose it accurately as the treatment approach differs, from radical surgeries in malignant cases, to a simple excision in hamartoma. We present an unusual case of bilateral REAH that was misdiagnosed, and hence it was treated aggressively.

Case report

A 57-year-old male patient presented with anosmia, 2-years history of bilateral nasal obstruction, and was accompanied with a moderate headache. An impression of olfactory neuroblastoma was made after history taking physical examination, and imaging studies. The patient underwent Functional Endoscopic Sinus Surgery (FESS), excisional biopsy of the cribriform plate mass bilaterally, and superior septectomy. Histopathologic examination of the bilateral masses showed sinonasal polyposis with crypting of surface mucosa and pseudoglandular formation. A diagnosis of sinonasal polyps with REAH was established. The patient's nasal obstruction improved, with no recurrence of sinusitis ± polyposis. However, he still complains of anosmia after 2-years follow-up.

Conclusion

Although REAH is a benign disease, it is critical to reach the correct diagnosis, in order to avoid aggressive treatment. Unfortunately, the preoperative investigations were not consistent with REAH, thus it was misdiagnosed and treated aggressively.

•

Respiratory Epitheliel Adenomatoid Hamartoma (REAH) is a benign disease that can resemble other malignant diseases.

•

The disease is commoner in males and in the third to ninth decades of life.

•

The significance of this article is to share our experience with this disease as we did not diagnose the case accurately. Thus the patient was treated aggressively for a malignant case, instead of a simple excision. Hence, one should keep REAH in mind when encountered a similar case to ours.

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.

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.

Respiratory Epithelial Adenomatoid Hamartomas: An Increasingly Common Diagnosis in the Setting of Nasal Polyps

Background

Respiratory epithelial adenomatoid hamartomas (REAH) are benign nose neoplasms found in the nasal cavity and sinuses. Symptoms include anosmia, nasal obstruction, facial pressure, and rhinorrhea. Although previously thought to be rare, these tumors are being increasingly recognized on pathology in patients undergoing endoscopic sinus surgery. However, REAH is difficult to diagnose before surgery because it may mimic other entities, such as nasal polyps or inverted papilloma, and is often found incidentally only after surgery.

Objective

The aims of this study were to (1) add an additional case series of REAH to the literature, (2) report unique imaging findings on computed tomography and magnetic resonance imaging, and (3) pool and summarize all available data from existing publications.

Methods

Retrospective chart review from years 2004 to 2015 and a literature review

Results

Twenty-three cases were found in our case series, which included 12 men (52%) and 11 women (48%), with a mean age of 59 years. No cases were found before 2007. Lund-Mackay scores were comparable with those found in chronic rhinosinusitis without nasal polyposis. Imaging consistently demonstrated a discoid-shaped mass at the olfactory cleft. Fifty previous publications were found (4 prospective, 11 retrospective studies, 9 case series, 26 cases reports), which included 660 patients diagnosed with REAH. Pooled data revealed a mean age of 54 years (range, 9–86 years) and a male to female ratio of 3:2.

Conclusion

The results of our study further refined the average age at which REAH diagnosis occurs as 54 years old, although it may occur at any age. There is a clear male-to-female predominance (3:2). In addition, olfactory cleft widening and discoid soft tissue at the olfactory cleft are hallmark radiographic findings. The vast majority of published cases occurred during the past 4 years, which indicated increased recognition of REAH.

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.

Predictors of respiratory epithelial adenomatoid hamartomas of the olfactory clefts in patients with nasal polyposis

OBJECTIVES/HYPOTHESIS

To look for predictors of respiratory epithelial adenomatoid hamartomas (REAH) development in patients operated for nasal polyposis (NP) by adjusting on confounding factors.

STUDY DESIGN

Prospective study.

METHODS

One hundred and six patients with NP, endoscopically operated between September 2009 and March 2012 on the ethmoidal labyrinths and olfactory clefts, were enrolled in this study. Clinical data was collected 1 day prior to surgery by using a standard grid without knowledge of any histological features. Patients were then divided into two groups based on operative and pathological reports: with and without REAH in the olfactory cleft (REAH-OC). The multivariate logistic regression model was used to assess independent factors linked to the presence of REAH-OC in patients with NP.

RESULTS

The mean duration of NP disease in patients with REAH-OC was about 13.95 ± 10.8 years versus 5.7 ± 5.6 years in patients without REAH-OC (P < 0.0001). Seventy-four percent of patients with REAH-OC had undergone one or more NP-related surgeries in their lifetime, in contrast with 49.21% of patients without REAH-OC (P = 0.009). According to the multivariate logistic regression analysis, those patients experiencing NP ≥ 10 years (OR 4.0, 95% CI 1.304-12.062, P = 0.015) and those with asthma (OR 2.5, 95% CI 1.004-6.29, P < 0.05) were at an increased risk of developing REAH-OC.

CONCLUSION

The development of REAH in patients with NP appears as a specific disease of the mucosa of the OC, induced by a long-lasting and/or severe inflammation of the olfactory clefts.

LEVEL OF EVIDENCE

4.

CT findings of sinonasal respiratory epithelial adenomatoid hamartoma: a closer look at the olfactory clefts

BACKGROUND AND PURPOSE

Respiratory epithelial adenomatoid hamartoma is a benign glandular neoplasm of the sinonasal cavities, which presents in isolation (REAHi) or in the setting of an adjacent inflammatory process such as sinonasal polyps. It is frequently found in the olfactory clefts. CT features of the 2 clinical presentations have not been well defined. We present the CT findings of REAH, focusing on the degree of associated sinusitis and changes in the OCs. We hypothesized that widening of the OCs and associated severity of the sinusitis are diagnostic features of REAH, differentiating it from SNP.

MATERIALS AND METHODS

In this case-control study, we compared patients with REAHi, those with REAH in the setting of SNP (REAHsnp), and those with SNP only (control patients). Patients with REAH were excluded if they had an adjacent inflammatory process other than SNP or if they did not have disease in the OC. We analyzed Harvard sinus CT scores and OC dimensions.

RESULTS

A total of 29 patients with REAH were included: 7 with REAHi and 22 with REAHsnp. A total of 26 control patients were identified. Patients with REAHi had significantly lower Harvard CT scores than did the other groups. The OC width and the ratio of OC to the total nasal distance were significantly larger in both REAH groups compared with those of the control patients. If the OC is 10 mm or more, the sensitivity and specificity for the presence of REAH are 88% and 74%, respectively.

CONCLUSIONS

Both clinical presentations of REAH are associated with OC widening on CT scan. In the setting of polypoid disease, an OC width of > 10 mm should increase suspicion for the presence of REAH.