Ceruminous Adenoma of the External Auditory Canal: A Case Report with Imaging and Pathologic Findings

Abstract

Ceruminous adenomas are benign tumors that are rare in humans and present with a nonspecific symptomatology. The treatment of choice is surgical excision. We present an 87-year-old woman who presented with a reddish, tender, round, soft mass of the outer third of the inferior wall of the left external auditory canal, discharging a yellowish fluid upon pressure. Coincidentally, due to her poor general condition, this patient also showed symptoms consistent with chronic otitis media, parotitis, and cervical lymphadenopathy, such as otorrhea, through a ruptured tympanic membrane and swelling of the parotid gland and cervical lymph nodes. The external auditory canal lesion was surgically excised under general anesthesia, utilizing a transmeatal approach. The pathological diagnosis was ceruminous gland adenoma. The tumor was made of tubular and cystic structures and embedded in a fibrous, focally hyalinized stroma. Immunohistochemistry confirmed the presence of two distinct cell populations. The luminal cells expressed keratin 7, while peripheral (basal) cells expressed keratins 5/6, S100 protein, and p63. The apocrine gland-related antigen GCDFP-15 was focally expressed by tumor cells. The postoperative course was uneventful and at the 2-year follow-up no recurrence of the ceruminous adenoma was noted.

Figure 1

CT imaging depicting otitis media of the left ear with external ear canal obstruction (∗) due to the cystic lesion.

Figure 2

H/E ×40. The tumor is made of tubular and cystic structures.

Figure 3

H/E ×100. Two cystic-tubular formations lined by columnar cells with an eosinophilic cytoplasm are seen.

Figure 4

Immunostain for keratin 7 (×100): luminal cells are labelled.

Figure 5

Immunostain for p63 protein (×100): nuclear positivity is seen in basal cells.