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Lipomas of the
internal auditory canal--report of two cases and review of the
literature. Zentralbl Neurochir.2004 May;65(2):88-94.
OBJECTIVE:
Lipomas of the internal auditory canal are extremely rare. So far,
only 21 cases have been described in the literature. We present here
two of our own cases and review the literature to date with special
emphasis on the diagnostic and therapeutic options. METHOD: During
the last seven years two lipomas of the internal auditory canal were
surgically treated in our department. Despite native and
gadolinium-enhanced MRI and a thin-sliced temporal bone CT scan they
were misdiagnosed as intracanalicular acoustic neurinomas. RESULTS:
Total tumour removal could be achieved, the facial nerve function
was conserved, but both patients were rendered functionally deaf
after surgery. CONCLUSION: Lipomas' radiological behaviour may mimic
acoustic neurinomas; without fat-suppressed T(1)-weighted images
they are often preoperatively misdiagnosed as acoustic neurinomas.
Although the postoperative morbidity with respect to cochlear and
facial nerve function is much higher than in small acoustic
schwannomas, early surgery may be justified, because complete
removal is only possible in this stage. No reliable data are
available concerning the natural history of this kind of lesion.
Internal
auditory canal mass in a 46-year-old woman. Arch Pathol. Lab Med.2005
Nov;129(11):1491-2.
Diagnosis and
treatment of lipomas of the internal auditory canal. Ear Nose Throat
J.2001 May;80(5):340-2, 345.
A Chinese
woman came to the otolaryngology department with a complaint of a
longstanding progressive left hearing loss and intractable tinnitus.
A finding of asymmetry on sensorineural hearing loss and auditory
brainstem response testing provided evidence of a retrocochlear
lesion on the left side. Computed tomography and magnetic resonance
imaging detected a tumor in the left internal auditory canal (IAC).
In addition to these radiologic features, our suspicion of the
possibility of an IAC lipoma was raised by the observation of
multiple lipomas over the patient's trunk and limbs. The patient
underwent a complete tumor resection via the translabyrinthine
approach, Pathology confirmed the diagnosis of an IAC lipoma.
Although we were not able to preserve the hearing in her left ear,
the patient was satisfied that we had relieved her constant tinnitus.
In this article, we review the particulars of this case and discuss
the clinical, radiologic, and pathologic features of IAC lipomas.
Lipomas of the
internal auditory canal and cerebellopontine angle.
Laryngoscope.1998 Oct;108(10):1459-69.
OBJECTIVE:
To evaluate lipomas of the internal auditory canal (IAC) and
cerebellopontine angle (CPA). STUDY DESIGN: Retrospective review.
METHODS: Review of a multi-institutional series of 17 lipomas of the
IAC/CPA, combined with a Medline review of the 67 cases reported in
the world literature. RESULTS: This series of 17 IAC/CPA lipomas is
the largest reported series to date, bringing the total number of
documented cases to 84. There appears to be a nearly 2:1 male to
female predominance. Sixty percent were left-sided lesions, and
three were bilateral. Hearing loss, dizziness, and tinnitus were the
most common presenting symptoms. Surgical resection was performed in
52 (62%) of these lesions; however, total tumor removal was
accomplished in only 17 (33%), which is most likely because of the
fact that these tumors tend to have a poorly defined matrix and a
dense adherence to neurovascular structures. Sixty-eight percent of
patients experienced a new deficit postoperatively, 11% were
unchanged, and only 19% improved with no new deficit. Only one
documented case of tumor growth was identified; however, the
reported follow-up was short (average, less than 3 years).
CONCLUSION: With the magnetic resonance imaging techniques now
available, lipomas can be reliably differentiated from other masses
within the CPA and IAC, so histopathologic diagnosis is rarely
necessary. Because of the potential for significant morbidity with
resection of these lesions, we believe that conservative follow-up
is the best treatment option for patients with these rare lesions.
Surgery is indicated only when significant progressive or disabling
symptoms are present.
Lipoma of the
internal auditory canal. Report of two cases simulating acoustic
neuroma. Ann Pathol.1998 Feb;18(1):52-4.
We report
two cases of intra-auditory canal lipoma, presenting as acoustic
neuroma, observed in respectively 45 and 53 year old patients.
Cerebellopontine angle lipomas are unusual lesions, more exceptional
than their intracranial counter-parts. The knowledge of these
tumoral lesions and of their close relationships with cranial nerves
incite to perform a frozen section when imagery is evocative, to
limit functional postoperative sequelae.
Lipomas of the
internal auditory canal. Laryngoscope.1997 Mar;107(3): 364-8.
Lipomas of
the internal auditory canal (IAC) are rare, benign neoplasms
occurring in the third to fifth decade of life predominately in
Caucasian males. Eleven cases of IAC lesions have been previously
reported; we report four more. Two of four cases showed atypical
findings on preoperative radiographic evaluation. These two patients
had surgery. Two patients with small tumors elected for observation
with close follow-up. Fat suppression of T1-weighted images on
magnetic resonance imaging (MRI) offers the most precise
preoperative diagnostic tool of IAC lipomas. Because of the
infiltrative nature of these tumors, hearing conservation surgery is
unlikely to succeed. We recommend observation for those patients
with small tumors and serviceable hearing.
Lipomas of the
internal auditory canal. Arch Pathol Lab Med.1996 Jul;120(7):681-3.
Lipoma of
the internal auditory canal is a rare tumor that may be confused
clinically with the much more common vestibular schwannoma. We
present two cases of lipoma of the internal auditory canal. The
clinical presentation is indistinguishable from that of vestibular
schwannomas. The high signal intensity on T1-weighted magnetic
resonance imaging, both with and without contrast, is consistent
with other reports of lipoma. Review of the literature shows that
lipomas of the internal auditory canal are histopathologically
similar to lipomas of the cerebellopontine angle. The symptoms,
erosive effect on the auditory canal, and gross appearance of this
uncommon tumor are sometimes difficult to differentiate from those
of a vestibular schwannoma. The diagnosis can be established by
intraoperative examination of frozen sections.
Lipoma of
internal auditory canal. Otolaryngol head Neck Surg.1992
Sep;107(3):374-6.
Lipoma of
the internal auditory canal is a rare tumor. Clinically, it presents
like an acoustic tumor. The diagnosis can be made with the use of a
magnetic resonance imaging showing a high intensity on T1- and low
intensity on T2-weighted image with no enhancement. Pathologically,
this is a soft, smooth, yellow tumor with some fat in it that can
resemble grossly any acoustic tumor. The lipoma is intermixed with
the eighth nerve and can be adherent to adjacent structures. The
growth of a lipoma can be slower than an acoustic tumor. A patient
diagnosed with lipoma of the internal auditory canal can often have
quite good hearing. As an alternative to surgical removal, another
therapeutic option is to watch the growth of the lipoma with
periodic magnetic resonance imaging, probably on a yearly basis
initially.
Lipomas of the
internal auditory canal. Laryngoscope.1991 Oct;101 (10):1031-7.
Intracranial
lipomas are rare tumors which may occur in the cerebellopontine
angle (CPA) or internal auditory canal (IAC). Although seemingly
innocuous in other parts of the body, lipomas within the CPA and IAC
often involve the surrounding cranial nerves, making attempts at
hearing conservation largely unsuccessful. In an attempt to
differentiate the IAC lipoma from the more commonly found acoustic
schwannoma, the preoperative imaging studies (magnetic resonance and
computerized tomography) on five previously unreported cases of IAC
lipomas were evaluated. Based on these studies, features were
determined that may allow the surgeon to diagnose IAC lipomas
preoperatively. These features will be discussed, as well as the
surgical and pathological findings.
Lipoma of the
internal auditory canal. An anatomo-clinical case study and review
of the literature about cranial nerve lipomas. Arch Anat Cytol
Pathol.1991;39(4):147-50.
A
36-year-old female presented with vertigo and worsening of a right
hearing loss with tinnitus. Clinical and radiologic investigations
revealed a tumor of the right internal acoustic meatus, first
diagnosed as a neuroma. Histologic study of surgical samples led to
a final diagnosis of lipoma. Cranial nerve lipomas are rare and
usually located in the cerebellopontine angle. Lipomas confined to
the internal acoustic meatus are much rarer. The review of the
literature however, shows that their histologic characteristics and
their behavior are identical to those of cerebellopontine angle
lipomas, and that a minimal surgical resection is therefore advised.
Lipomas of the
internal auditory canal. Arch Otolaryngol.1978 Aug;104 (8):431-6.
We present
two cases of lipoma of the cerebellopontine angle (CPA), which
brings, to our knowledge, the total reported in the literature to
six. These cases had a clinical, surgical, and postoperative course
that was similar to a small acoustic neuroma. The roentgenographic
aspects were in keeping with small, CPA tumors. A review of the
literature of CPA tumors and lipomas of the CNS is presented. We
discuss the controversy surrounding the origin of lipomas of the
CNS.
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