Ceruminous Gland Adenocarcinoma of External Ear Canal

The Korean Journal of Pathology
2007; 41: 66-8
Ceruminous Gland Adenocarcinoma of External Ear Canal
- A Case Report -
Jung Weon Shim
Department of Pathology, Hangang
Sacred Heart Hospital, Hallym University,
Seoul, Korea
Received : January 11, 2007
Accepted : January 17, 2007
Ceruminomas are rare tumors arising from the ceruminous gland, which is a modified apocrine
gland in the skin of the external ear canal. There is controversy about these rare tumors
regarding their histological classification, their origin and the importance of wide excision, and
there is also terminological confusion for making the diagnosis. Ceruminous adenocarcinoma
is a malignant subtype of ceruminoma. We report here on a case of adenocarcinoma of
the ceruminous gland in a 71-year-old male patient.
Corresponding Author
Jung-Weon Shim, M.D.
Department of Pathology, Hangang Sacred Heart
Hospital, 94-200 Yungdungpo-dong,
Youngdeungpo-gu, Seoul 150-037, Korea
Tel: 02-2639-5571
Fax: 02-2637-9352
E-mail: modshim@chol.net
Key Words : Ear canal; Ear neoplasms
The external ear canal (EAC) is divided into two sections: the
inner two thirds are osseous, whereas the outer third is cartilaginous.
The skin of the bony portion contains few appendages,
and the skin of the cartilaginous portion shows numerous hair
follicles, sebaceous glands and a specialized type of apocrine sweat
glands: ceruminous gland. The eccrine sweat glands are absent
in the EAC. Ceruminous gland tumors are rare, and only about
100 cases have been reported to date in the English literature. 1
Several controversial issues such as nomenclature, classification,
histogenesis and diagnosis remain.
CASE REPORT
A 71-year-old man presented with a 1-year history of otalgia
and otorrhea in the left ear. He also complained of left facial weakness,
intermittent dizziness and hearing problems; the rest of
his medical history was unremarkable. The physical examination
and otoscopy showed an exophytic, 2 cm sized mass that
fulfilled the anterior part of the left EAC. The patient’s oral cavity,
oropharynx, larynx, neck and thyroid examinations were
normal. An MRI scan of the temporal bone showed a mass occupying
the left EAC with involvement of the tympanic membrane
and middle ear; it was infiltrating into the skin of the ear canal,
and eroding into the regional bony tissue (Fig. 1).
The patient underwent open cavity mastoidectomy and tympanoplasty
of the left ear. The operation finding showed that the
tumor was located at the intersection between the osseous and
cartilaginous portions of the ear canal, filling approximately twothirds
of the external ear and mastoid cavity. The tumor showed
abundant feeding vessels growing into the regional dura and
brain. Total excision of the soft portion within the tumor was
done together with meatoplasty and reconstruction with using
a free skin graft. The patient’s facial palsy persisted after the operation.
Three months later, the tumor seemed to have invaded
into the brain base.
The excised tumor specimen was 1.5×1×1 cm in dimension.
The cut surface of the mass showed a yellow white solid appearance
with focal ulceration. Histologically, the tumor consisted
of tubular or glandular lesion that was lined by stratified or single-layered
tumor cells (Fig. 2). These cells showed abundant,
granular, eosinophilic cytoplasm, and frequent apical snouts or
blebs, indicating the decapitation-type secretion, being consistent
with cells of apocrine derivation (Fig. 3). There was mod-
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Ceruminous gland Adenocarcinoma of External Ear Canal 67
Fig. 2. Adenocarcinoma of ceruminous gland shows proliferation
of tubular or glandular lesion (H&E, ×200).
Fig. 1. An MRI scan shows a mass in the left external ear canal with
destruction of regional bone tissue.
Fig. 4. Adenocarcinoma destroys the regional bone tissue (H&E,
×200).
Fig. 3. There is frequent snouting of the tumor cell cytoplasm into the
lumen, being consistent with apocrine differentiation (H&E, ×400).
erate nuclear pleomorphism and occasional mitoses, in keeping
with adenocarcinoma. There were few myoepithelial cells, as was
proved by perfoming immunohistochemistry for S-100 protein
and smooth muscle actin. The surrounding tissue was desmoplastic
with mixed acute and chronic inflammation. The tumor
infiltrated into and destroyed the regional bone tissue (Fig. 4).
DISCUSSION
The term ‘‘ceruminoma’’ has long been used as a collective
denomination for all ceruminous gland tumors. Such nomenclature
has caused confusion regarding differentiating between a
lesion’s benign and malignant nature. So, the term ‘ceruminoma’
was excluded from the WHO classification in 1991, 2 but
unfortunately, it is still being employed until now.
Wetli et al. 3 distinguished four categories for ceruminomas:
the ceruminous adenoma, the ceruminous adenoid-cystic carcinoma,
the ceruminous adenocarcinoma and the pleomorphic
adenoma. In 1977, Pulec 4 described two cases of a fifth entity:
the mucoepidermoid carcinoma. A large cohort study on ‘ceruminoma’
has not yet been done and the only reported incidence
of ceruminous adenocarcinoma arising out of ceruminoma was
9 out of 52 cases. 3 The criteria for making the diagnosis of malignancy
may be 1) cytologically bland features with an infiltrating
margin or 2) the tumor has obviously malignant cytological
features, such as significant nuclear pleomorphism, or a brisk
mitotic rate. 5 Ceruminous adenocarcinoma can be classified as a
low or high grade adenocarcinoma depending on the degree of

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Jung Weon Shim
atypia. 6 The histology of ceruminous adenocarcinoma usually
shows irregular glandular structures lined by cuboidal epithelium,
and this epithelium shows apocrine features such as
luminal blebbing or snouting. 6 Adenoid cystic carcinoma could
be differentiated from adenocarcinoma in that the former type
shows cords and islands of uniform, rounded, darkly-staining
cells that show pseudoglandular formation, but there is no peripheral
palisading or evidence of true gland formation and there
is a characteristic cribriform architecture and perineural invasion.
6 It is clinically important to differentiate low-grade adenocarcinoma
from a ceruminous adenoma. A sufficient tissue
sample should be analyzed for the findings of stromal or bone
invasion and desmoplasia in benign looking ceruminomas. Highgrade
adenocarcinomas extensively infiltrate the surrounding
tissues as irregular glands and sheets of overtly malignant cells.
They show marked nuclear pleomorphism and abundant mitotic
figures, and they may exhibit little or no evidence of apocrine
derivation. 7 In this case, tubular or glandular lesion with moderate
cytological atypia, and invasive growth into the regional bone
tissue matched the criteria of adenocarcinoma. The tumor cells
frequently showed abundant eosinophilic cytoplasm and intraluminal
decapitation that fit with a ceruminous gland origin.
Ceruminous adenocarcinoma exhibits a prolonged subclinical
phase, often lasting for years before presentation, 8 as happened
in our case. The clinical symptoms usually comprise a sensation
of blockage in the EAC with or without hearing loss. Otoscopic
examination usually demonstrates nodules covered by normal
skin, with or without otorrhea, hemorrhage, lymphadenopathy
or cranial nerve palsies. In contrast, ceruminous and pleomorphic
adenomas present as painless nodules with or without hearing
loss. Temporal bone CT scan or MRI is usually recommended
to determine the extent of the lesion and the presence of osseous
invasion, and to exclude extrapetrosal disease or metastasis. 5
If the histopathologic analysis does not confirm a tumor’s
benign nature, then the diagnosis, based on a large amount of
tissue, should be reanalyzed and en bloc excision with resection
margins of 3 to 4 mm should be performed because the exact
nature of the tumor is hardly identifiable at the time of surgery.
Further, even benign and well-limited tumors, such as ceruminous
adenomas have a high recurrence rate. Thompson et al. 9
reported 4 out of 41 cerumious adenoma developed the recurrence
due to incomplete excision. In Korea, one cerumious adenocarcinoma
has been recently reported on.
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