Ceruminous adenomas: a clinicopathologic study of 41 cases with a review of the literature.

BACKGROUND: Ceruminous gland neoplasms are rare neoplasms. To date, a large clinicopathologic study of benign ceruminous gland neoplasms has not been reported.

DESIGN: Forty-one cases of ceruminous gland adenomas diagnosed between 1970 and 2000 were retrieved from the files of the Armed Forces Institute of Pathology. Histologic features were reviewed, immunohistochemical analysis was performed (n = 21), and patient follow-up was obtained (n = 40).

RESULTS: The patients included 22 men and 19 women, 24 to 85 years of age (mean, 54.2 years). Patients presented clinically with a painless mass of the outer half of the external auditory canal (n = 33) or with hearing changes (n = 11). Symptoms were present for an average of 16.3 months. The polypoid masses affected the external auditory canal only and ranged in size from 0.4 to 2 cm in greatest dimension (mean, 1.1 cm). Histologically, the tumors demonstrated glands and small cysts lined by a tubuloglandular proliferation of inner ceruminous cells (cerumen-secreting epithelium with decapitation secretion) subtended by a spindled to cuboidal myoepithelial layer. A hyalinized stroma created an infiltrative pattern of growth; surface involvement (n = 8) was seen. Tumors were divided into ceruminous adenoma (n = 36), ceruminous pleomorphic adenoma (n = 4), and syringocystadenoma papilliferum (n = 1) types. The luminal cells were strongly and diffusely immunoreactive with CK7, while the basal cells were highlighted with CK5/6, S-100 protein, and p63. CD117 highlighted the luminal cells preferentially. The proliferation markers revealed a low index. Adenocarcinoma and middle ear adenoma are the principal differential consideration. Surgical excision was used in all patients. Four patients developed a recurrence due to incomplete excision. All patients were without evidence of disease at the last follow-up: alive (n = 28, mean 16.3 years) or dead (n = 12, mean 11.8 years).

CONCLUSION: Ceruminous gland adenomas are the most common external auditory canal tumors. They demonstrate a dual cell population of basal myoepithelial-type cells and luminal ceruminous (ceruminal) cells. Cerumen pigment, CK7, and p63 can help to distinguish this tumor from other neoplasms that occur in the region. Complete surgical excision results in an excellent long-term clinical outcome.