GLOMUS TUMORS - Asalam 0 Alaikum (Peace Be Upon You)
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Transcript GLOMUS TUMORS - Asalam 0 Alaikum (Peace Be Upon You)
GLOMUS TUMORS
Department of Otorhinolaryngoglogy
2nd Hospital affliatted to Medical college of Zhejiang University
Xu Yaping
Definition
Glomus tumors are generally benign neoplasms of arising
from neuroectodermal tissues, found in various parts of
the body.
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Pathology
catecholamine + sustentacular cells (modified Schwann cells)
+a rich network of capillaries and venules.---- "zellballen"
"light" and "dark" cell subpopulations, referring to the density of
intracellular neurosecretory granules.
Chief cells are members of the amine precursor and uptake
decarboxylase (APUD) family, as the DNES (diffuse neuroendocrine
system).
related to the adrenal medulla, and their neoplastic counterpart in the
adrenal gland is the pheochromocytoma.
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The extra-adrenal versions have various names including
non-chromaffin paragangliomas,
aragangliomas, chemodectomas,
glomerocytomas,
receptomas,
tympanic body tumors,
carotid body tumors,
and a few others.
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Synchronous glomus tumors are not the only associated neoplasms.
Several authors have reported an association with other neoplasms
(benign and malignant).
Spector et. al. reported a 7% incidence in his series of 95 patients.
thyroid C-cell carcinoma,
parathyroid adenomas,
pheochromocytomas,
the MEN syndromes,
visceral neoplasms of neural crest origin.
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In the head and neck,
two anatomic groups of paragangliomas can be
differentiated:
cervical paragangliomas
temporal bone ( jugulotympanic) paragangliomas.
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The cervical group includes primarily carotid body tumors
glomus vagale or intravagale tumors,
The jugulotympanic refers to glomus jugulare
glomus tympanicum tumors.
--------- the second most common temporal bone tumors
The first is the acoustic neurinomas.
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Epidemiology
The incidence of glomus jugulare tumors is 1:1,300,000 population.
the predominant incidence in females. The female:male incidence
ratio is at least 4:1.
The incidence of malignancy in glomus tumors is believed to be low
(<5%).
Patient age averages 50 to 60 years , and highly variable.
Catecholamine secreting ( "functional") tumors occur in 1% - 3% of
cases.
There is no racial or ethnic predilection.
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Clinical Presentation
Symptoms are insidious in onset.
pulsatile tinnitus: most common, tinnitus is secondary to mechanical
impingement on the umbo is most cases.
aural fullness,
conductive hearing loss.
Sensorineural hearing loss on the side of a glomus tumor is the
hallmark of labyrinthine invasion.
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Physical examination
a red or reddish-blue mass seen behind the tympanic membrane.
The diagnosis of glomus tympanicum can only be entertained if the
examiner can see a full 360 degrees around the perimeter of the
lesion, otherwise the presumptive diagnosis must be a glomus
jugulare.
The finding of a middle ear mass is fairly reliable, with 94 - 100% of
untreated cases demonstrating this in reviews of large series of
patients.
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Brown's sign (blanching of the mass with positive pressure
pneumotoscopy) is often mentioned, but the frequency of this finding
is not clear.
Rarely, a friable or bleeding mass in the EAC may be the presenting
sign with larger tumors.
tachycardia, tremor, or complaints of vascular headaches should
alert for the possibility of a functional tumor.
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Cranial nerve deficits are seen primarily with larger tumors
compression or invasion of CN's IX, and X most commonly
CN's VII, VIII, XI, and XII affected less often.
Isolated deficits of CN's VII and VIII are more likely to be
secondary to a tympanicum.
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Diagnosis and Preoperative Evaluation
clinical grounds: the presumptive diagnosis
CT, MRI: the size and extent
sometimes angiography: the primary blood supply to tumor.
A myringotomy for purposes of obtaining tissue should not be
performed on a middle ear mass.
If a tissue biopsy is to be obtained (not usually necessary) a
transmastoid approach should be used.
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Differential diagnoses
neural lesions (neurolemmoma, neurofibroma, chordoma),
osteoblastoma,
adenomas, adenocarcinomas,
inflammatory polyps,
cholesterol granulomas,
rare lesions such as histiocytosis, fibromyxoma, melanoma,
rhabdomyosarcoma, lipoma, plasmacytoma, or metastatic lesions
(lung, breast, prostate),
almost all of these can be excluded with the appropriate physical
examination and radiological studies.
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Treatment
surgical excision: Glomus Tympanicum
The appropriate treatment of glomus tympanicum tumors isolated to
the middle ear, middle ear and mastoid, or even the inner ear (Fisch
classifications A & B)
Glomus tympanicums can be completely excised in over 90% of
cases with standard otologic approaches.
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Glomus Jugulare:
surgical excision, radiation therapy, surgery and
radiation, or observation.
The argument over the relative merits of surgery vs radiation center on
their complications and efficacy. With advances in skull base
techniques, surgery is generally efficacious, so the decision on
treatment mode often centers on the potential morbidity of the
surgery, and other patient factors.
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Thank you!