Respiratory Epithelial Adenomatoid Hamartoma of the Nose: An Updated Review

Abstract

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 Typical but Underdiagnosed Nasal Cavity Mass

“…Since the lesion was only added to the World Health Organization classification of tumours in 2005 REAH is still a relatively unknown and therefore underdiagnosed entity [23]. Thus far it is only sporadically documented in relatively small series and a few case reports.…”

“…The site of origin is typically the olfactory cleft, which is the area between the superior turbinate, cribriform plate and septum, lined by specialized olfactory epithelium [3]. REAHs can be isolated or associated with nasal polyposis and are present bilaterally in most cases.…”

“…Non-aggressive endoscopic surgical excision is the current treatment of choice. Recurrence rate is reported to be low, but this is still uncertain since only studies with a short follow-up period (up to 3.8 years) are available [3]. …”

“…The different predilection site can sometimes aid in the differential diagnosis as REAH originates in the anterior half of the olfactory cleft and nasal polyps in the ethmoidal labyrinth, protruding into the nasal cavity. The effect of oral steroid treatment can also help since sinonasal polyps generally respond to this treatment and REAHs persist [3]. Other important differential diagnoses are adenocarcinomas which generally appear more aggressive and encephaloceles and esthesioneuroblastomas which would be associated with a cribriform plate defect [456].…”

Bilateral Respiratory Epithelial Adenomatoid Hamartomas Originating from the Anterior Olfactory Clefts

“…REAH was fi rst described in 1995 by Wenig and Heff ner (2). Since then, at least 394 cases of REAH have been reported, with a 3:2 male-to-female ratio (3). REAH displays distinct histopathological features characterized by polyps with pseudoglandular proliferation lined by ciliated respiratory epithelium (4).…”