Xanthogranuloma in the External Auditory Canal in Childhood, an Unexpected Lesion

Abstract

Pedunculated lesions in the external auditory canal present a broad differential diagnosis. It is crucial to rule out malignant neoplasms and consider the possibility of xanthogranulomas, which are very rare in this location. Management is determined by associated complications, and otolaryngologists must consider this for appropriate treatment.

Clinical Case

We present the case of a 3-year-old boy who presented with a lesion in the right external auditory canal (EAC). The lesion had been progressively growing for two months, with associated episodes of otitis externa that improved after topical antibiotic treatment. On otomicroscopic examination, a 9 mm polypoid, soft, and friable lesion was observed on the anterior wall of the cartilaginous EAC (Fig. 1A).

Fig. 1.

(A) A reddish polypoid lesion is identified in the external portion of the EAC. (B and C) Diffuse proliferation of histiocytes accompanied by lymphocytes, eosinophils and polymorphonuclear cells, with the presence of abundant Touton-type giant cells (arrows) (HE; 40x; 100x). (D) Positive CD68 immunoreactivity confirms the histiocytic nature of the lesion (CD68; 100x)

Due to the rapid growth and recurrent infections caused by the occlusive nature of the lesion, a biopsy was performed, and the lesion was mostly excised. The clinical diagnosis was presumed to be a papilloma.

Histological examination revealed a diffuse proliferation of cells with wide eosinophilic cytoplasm and histiocytic appearance, which showed positive immunoreactivity for CD68, confirming their histiocytic nature. It had a significant inflammatory infiltrate composed of lymphocytes, plasma cells, eosinophils, and neutrophils. Multiple Touton-type giant cells were identified (Fig. 1B-D). These findings led to a diagnosis of xanthogranuloma.

The patient was referred to dermatology and ophthalmology to rule out systemic involvement and ocular complications. Currently, the patient is awaiting complete lesion resection due to persistent disease.

Discussion

Pedunculated lesions in the EAC present have a wide differential diagnosis. Xanthogranuloma is a rare histiocytic proliferation of non-Langerhans cells, being the most frequent of these [1]. The aetiopathogenesis of this lesion is unknown. Although a neoplastic origin has been proposed, it is currently classified as a reactive lesion. Xanthogranuloma is now understood as a histiocyte proliferation with progressive lipidisation in response to a traumatic or infectious stimulus [2]. Recent studies suggest the involvement of the extracellular signal-regulated kinase (ERK) pathway due to pathological activation, indicating a genetic predisposition to the development of these lesions [3].

Xanthogranuloma is more commonly found in children, especially in the first two years of life, although up to 10% of patients are adults, with a peak incidence between the third and the fifth decade [1]. They usually appear as single dermal lesions, yellowish-brown papules or nodules, mainly on the head and neck region, and tend to resolve spontaneously [4, 5]. However, they can be associated with a systemic condition characterised by multiple lesions, which may appear in any organ and usually require treatment [1].

It is important to consider the possibility of xanthogranuloma as an extracutaneous lesion, particularly in the ocular sphere, where it can cause uveal compromise or pose a risk of haemorrhage and glaucoma. Uncommon locations are the tympanic membrane, gastrointestinal tract, or lungs, with a worse prognosis when associated with dermal lesions [2].

Xanthogranuloma involving the EAC is very rare, with only nine cases reported in the English literature, three of them in children [6, 7] (Table 1). Typically, it presents as a polypoid lesion in the cartilaginous portion of the EAC. In our case, we identified a lesion confined to the right EAC with progressive growth over several months, which initially raised suspicion of benign soft tissue lesions.

Table 1.

Cases reported in the literature of Xanthogranuloma in EAC.

Author and year	Age (years) / gender	Symptoms	Macroscopy	Location
Goldman et al.; 1995 [7]	13 / ♀	Otalgia and otorrhagia	Reddish polyp	1/3 outer right EAC
Lee et al.; 2009 [8]	43 / ♂	Otic fullness	Soft mass	Left EAC
Lin et al.; 2012 [5]	27 / ♂	Asymptomatic	Rounded lesion	1/3 outer right EAC
Yoshihama et al.; 2012 [9]	24 / ♂	Otorrhagia	Mass	1/3 outer right EAC
Ginat et al.; 2016 [6]	10 / ♀	Otorrhoea and otorrhagia	Polypoid mass	1/3 outer EAC
	4 months / ♂	Otorrhagia	Subcutaneous mass	1/3 outer EAC
Hur et al.; 2016 [10]	48 / ♂	Hypoacusis and otalgia	Polypoid lesion	1/3 outer right EAC
Misra et al.; 2020 Pubmed id: 32,275,346	39 / ♀	Asymptomatic	Reddish polyp	Left meatus
Connell et al.; 2021 [4]	48 / ♂	Hypoacusis and otalgia	Polypoid lesion	1/3 outer right EAC
Present study	3 / ♂	Otitis externa	Soft polyp 9 mm	1/3 outer right EAC

The polypoid appearance requires a broad differential diagnosis, including papillomas, polyps or cysts. In addition, rapid growth may raise suspicion of a possible malignant lesion or cholesteatoma of the canal [2, 6]. Therefore, when a symptomatic lesion or with suspicious features of malignancy is present, biopsy or excision should be performed in order to reach a diagnosis by histopathological examination.

The tubular anatomy of the EAC can lead to secondary conditions such as recurrent otorrhoea due to recurrent infections, otorrhagia, conduction hypoacusis or eczema of the canal [4–10], which may suggest more significant underlying processes.

As a benign reactive disorder, xanthogranuloma tends to resolve spontaneously, leading to a wait-and-see attitude. However, in cases such as the one described, EAC lesions have the for local complications [4–10]. Surgical excision puts an end to these complications and provides a definitive diagnosis. In the reported cases, en bloc resection was performed, and no recurrence has been described during follow-up.

In conclusion, we describe a new case of xanthogranuloma in the EAC, which is only the fourth reported case in children. Although rare, otolaryngologists should consider this diagnosis when evaluating a lesion in the EAC.

Funding

This research did not receive any specific grant from any funding agency in the public, commercial, or not-for -profit sector.

Declarations

Ethics Approval and Consent to Participate

The study was approved by the Hospital Committee on Health Research Ethics. 2730-N-20. The use of tissue was not prohibited by the parents of the patient according to the Hospital Tissue Application Register. The parents of the patient gave informed consent for publishing.

Conflict of Interest

The authors have no relevant financial or non-financial interests to disclose.