Blue Ear Cyst: A Rare Eccrine Hidrocystoma of the Ear Canal and Successful Endoscopic Excision

Abstract

Aims. Hidrocystomas are benign cystic growths of the apocrine and eccrine sweat glands. These cystic lesions have been well documented on the face, head, and neck, but rarely in the external auditory canal. Presentation of Case. A 67-year-old woman presented with a bluish cystic mass partially occluding the external auditory canal and interfering with hearing aid use. Lesion was excised completely via a transcanal endoscopic approach with excellent cosmetic results, no canal stenosis, and no recurrence at 1-year follow-up. Discussion. We present a rare eccrine hidrocystoma of the external auditory canal and successful excision of this benign lesion. We describe the surgical management using a transcanal endoscopic approach and follow-up results. An eccrine gland cyst that presents as a mass occluding the external auditory canal is quite rare. There are only a few such cases reported in the literature. These masses can be mistaken for basal cell carcinomas or cholesterol granulomas but can be easily differentiated using histopathology. Conclusion. Eccrine hidrocystoma is a cystic lesion of sweat glands, rarely found in the external auditory canal. A characteristic bluish hue aids in diagnosis and surgical excision using ear endoscopy provides excellent control.

Eccrine Hidrocystoma of the Central Chest and Dermoscopic Findings

“…Currently, the diagnosis of eccrine hidrocystomas is confirmed via histologic examination [11]. Unlike eccrine hidrocystomas, apocrine hidrocystomas are characterized by secretory decapitation, periodic acid-Schiff (PAS)-positive granules, papillary projections, and columnar cells with eosinophilic cytoplasm [9,14]. Apocrine immunohistochemical stains, such as gross cystic disease fluid protein-15 and mammaglobin, may be used to assist in diagnosis, which were negative in our case.…”

“…Eccrine hidrocystomas are usually slow growing and asymptomatic [4,9]. On gross examination, they are typically 1-6 mm in size and can be solitary or multiple, tense, thin-walled, domeshaped, bluish, and cystic papules [3,4].…”

“…Intradermal botulinum toxin injections have led to successful resolution of these lesions of the face [5]. Other available treatments with varying efficacy include electrodesiccation, surgical excision, incision and drainage, pulsed dye laser treatment, and topical atropine and scopolamine [9,[17][18][19]. Defining the dermoscopic features of eccrine hidrocystomas may assist in monitoring for recurrence and resolution following treatment.…”

Malignant Myoepithelioma of the External Auditory Canal – a Rare Case Report with Literature Review and Clinical Importance of Foramen of Huschke

“…However, the external ear canal location is extremely uncommon [4]. Another hypothesis suggests that tumors can grow from the eccrine cells of the ear canal skin, considering the fact that the normal eccrine gland is also composed of epithelial and myoepithelial cells [17].…”

“…Malignant myoepitheliomas have a signi cant local recurrence rate of 42% and a lower risk of distant metastases of approximately 32-40% [9,17]. However, the nal pathology report could also describe in ltrative growth patterns as perineural invasion, demonstrating the aggressiveness of the tumor.…”