Mixed tumor of the external auditory canal

Pleomorphic Adenoma of External Auditory Canal: Case Report of First Endoscopic Resection and Literature Review

Ceruminous pleomorphic adenoma is a very rare, mostly benign tumor originating from the ceruminal glands in the external auditory canal. Histologically, it is a mixed tumor with epithelial and stromal parts of different proportions, and is recognized today by the World Health Organization (WHO) as a ceruminous adenoma. Similar to the pleomorphic adenoma of salivary glands, recurrence or malignant degeneration with cellular atypia and metastasis can occur on rare occasions. Here, we describe an 87-year old female patient with a growing spherical mass in the right external auditory canal. After exclusive endoscopic tumor resection, a ceruminous pleomorphic adenoma was histologically diagnosed. Due to the absence of nuclear pleomorphism, no increased mitotic rate, no perineural invasion and no fusion transcripts of the MYB or MYBL1 gene loci, an adenoid cystic carcinoma could be excluded. The postoperative course was without any evidence of complications. A literature review identified 44 articles with 49 patients that were considered. Hearing loss and ear sensations were the most commonly reported symptoms. Most cases underwent an excision via an endaural or retroauricular approach. Recurrences were described in four patients, three of which had a malignant transformation.

Lipomatous pleomorphic adenoma of the ceruminous gland

A case of lipomatous pleomorphic adenoma in the ceruminous gland is reported. A 69-year-old Japanese woman presented with a mass in the posterior wall of the cartilaginous external auditory canal. Light microscopic examination revealed a well-circumscribed tumor composed of tubular structures with apocrine secretion and ceroid deposition, extensive mature adipocytes, and spindle-shaped myoepithelial cells in the myxoid and fibrous stroma. This case demonstrates the peculiar location of a lipomatous pleomorphic adenoma in the external auditory canal.

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.

Metastasizing mixed tumor of the parotid: initial presentation as a solitary kidney tumor and ultimate carcinomatous transformation at the primary site

Benign mixed tumors of the salivary glands are generally regarded as indolent and harmless neoplasms. A subset of benign mixed tumors, however, can undergo carcinomatous transformation (that is, carcinoma ex-mixed tumor). Even more rarely, a mixed tumor that is seemingly benign at the microscopic level will metastasize like a true carcinoma (that is, metastasizing mixed tumor [MZMT]). Despite the benign appearance of the metastatic implants, there is usually little doubt regarding their true nature and origin. Patients invariably have had a mixed tumor removed from the parotid or some other salivary gland, and metastatic spread is usually preceded by multiple episodes of local tumor recurrence. We report a case of MZMT that presented as a solitary kidney mass. In the absence of a previous or concurrent salivary gland tumor, its metastatic nature was not appreciated and it was regarded as an unusual but benign kidney adenoma. One year after removal of the kidney mass, the patient presented with signs and symptoms of an aggressive parotid tumor. Pathologic examination of the tumor in the parotid demonstrated a high-grade carcinoma arising from a mixed tumor. This case underscores the importance of considering MZMT when a seemingly benign mixed tumor is encountered at a nonsalivary site, even in patients without a supportive history. Failure to do so may cause an unnecessary delay in primary tumor diagnosis and management, allow the primary tumor to progress toward a more malignant phenotype, and deny the patient a high expectation for a complete cure.

Pleomorphic adenoma of the external auditory canal: a case report and review of the literature

Pleomorphic adenoma arising in the external auditory canal is rare. We report the case of a 38-year-old man. To better grasp the clinical features and natural history of this uncommon tumour, we also reviewed the worldwide literature and found 24 similar cases, which we analysed together with our own.