S. Di Lorenzo; B. Corradino; A. Cordova; F. Moschella
Dipartimento di discipline chirurgiche ed oncologiche, sez. Chirurgia Plastica e Ricostruttiva, Universitą degli Studi di Palermo, Palermo, Italy
Vyšlo v časopise:
ACTA CHIRURGIAE PLASTICAE, 49, 3, 2007, pp. 77-79
tumors are classified as benign and malignant, and further
sub-classified as neural or non-neural in origin.
tumors comprise less than 5% of all tumors of the hand and upper
of the nerve sheaths are the most prevalent of the peripheral nerve
tumors and are divided in two categories, schwannomas and
nerve tumors are rare; the most common of these is the neurogenic
upper extremities schwannoma may arise from digital nerve, ulnar
nerve, median nerve, radial nerve and from brachial plexus; its
incidence is 0.8-2.1% of all upper extremity tumors (1, 2).
are benign, slow-growing neoplasms of neuroectodermal origin; they
are the most frequent of all nerve sheath tumors: these lesion arise
from Schwann’s cells that enveloped axons of the peripheral,
cranial and autonomic nervous system.
tumor originates from the nerve sheath in a focal manner as a
solitary and well-encapsulated mass; it tends to arise from a single
fascicle spreading and displacing the remaining fascicles within the
nerve sheath, occasionally it tends to protrude from the nerve.
occur as a solitary lesion, but they can occur as multiple lesions
and can affect one or several nerves.
schwannomas occur in two inherited tumor syndromes. Bilateral
vestibular schwannomas are pathognomonic of neurofibromatosis 2
(NF2), while in the absence of other NF2 features, they are
characteristic of a newly described syndrome, schwannomatosis (3).
tumor can also occur in association with neuro-fibromatosis.
trasformation may occur in patients with Von Recklingausen’s
disease and with large benign tumors, but the pathogenesis of this
transformation is not yet fully understood.
isolated ulnar schwannoma usually presents as a painless
mass with or without positive Tinel’s sign, and the mass may remain
asymptomatic for a long period of time (the irritative symptoms are
mass size related).
must be suspected in patients with a palpable mass of the upper
extremity, mobile, with or without neurological symptoms or signs.
careful history and physical examination is necessary for diagnosis
and management of ulnar nerve tumors; the history should include the
growth rate of the lesion, the presence of neurological deficit or
pain, a family history of neurofibromatosis or its stigmata, the
presence of other masses or systemic disease.
physical examination should focus on the size and location of the
lesion (olecranic region), the presence of tenderness and mobility,
Tinel’s sign, and any neurological deficits including sensory loss
ulnar nerve tumors are superficially located and can be moved
laterally rather than proximally-distally.
of the ulnar nerve may remain asymptomatic for a long period of time
because of the natural resiliency of the ulnar nerve and due to its
ability to tolerate the physiological stresses of normal daily
paucity of symptoms in a large nerve such as the ulnar nerve is a
result of the slow growth and non infiltrative nature of schwannomas,
to minimize nerve dysfunction, and to explain the normal nerve
nerve schwannomas arise from a single nerve funiculus; other funiculi
of the nerve remain unaffected while being pushed slowly to the
periphery of the neoplasm and may be subjected to only slight
compression, maintaining their integrity and function.
considerations explain the absence of clinical neurological symptoms,
pain, and the absence of significant alteration of the
electromyographic examination in many patients.
symptoms can be vague, tend to present late with an average interval
of up to 5 years before the diagnosis is established.
pain or paresthesia are reported in less than half of affected
people. Diagnostic tests such as ultrasound, CT, MRI can aid in
these ulnar nerve tumors are usually on relatively superficial
locations and therefore are suitable for US assessment (4).
can further localize the extent of solid mass but it is expensive and
difficult to obtain or to propose when there are not neurological
signs of nerve injury. Nerve conduction studies may be normal.
tests are not specific so there is a potential for high rate of
misdiagnosis with inadvertent nerve resection!
absence of specific clinical diagnostic tests and the rarity and
variable clinical presentation of Schwannoma result in the diagnosis
being determined intraoperatively.
appropriate index of suspicion is necessary for inclusion of
peripheral nerve tumors as a differential diagnosis of an upper
extremity mass (5, 6).
64-year-old male with 5-year history of a mass in the olecranic
region, referred to the Department of Plastic and Reconstructive
Surgery complaining of a growing, mobile and fusiform mass of his
left elbow, causing discomfort (not pain) and interfering with his
common daily activities.
patient denied any trauma or any pathology.
pathological anamnesis was not useful in obtaining further
information about the nature of the mass.
mass was associated with mild and sporadic discomfort due to its
size; clinical neurological examination was not helpful (Tinel’s
sign was negative).
of the olecranic region revealed a mobile mass, measuring 6x4 cm,
that displaced side to side, perpendicular to the axis of the ulnar
nerve, but not mobile in a longitudinal direction.
sensory and motor examination did not show any deficits.
conduction velocities were normal, as were motor and sensory
showed a circumscribed hypoechogenic homogeneous mass with distal
acoustic enhancement. Diagnostic tests were not specific.
confirmed the nervous origin of the mass.
surgical exposure of the ulnar nerve from the level of the epicondyle
and through the cubital tunnel was performed, splitting the flexor
carpi ulnari heads and delivering the ulnar nerve and its associated
tumor mass. The mass had a white-pink color, an elastic consistency
and a wrinkled surface (Fig. 1).
careful microscopic dissection of the ulnar nerve mass was performed,
separating the ulnar nerve involved fascicles from the mass, which
was completely excised with the fascicle involved using an
mass was sent to the pathologist, and the histology confirmed this
large mass as a benign schwannoma with B Antoni cells.
was quite uneventful and satisfactory. The patient had a normal ulnar
sensory and motor function postoperatively (ulnar nerve function
follow-up showed no evidence of residual or recurrent tumor.
nerve schwannoma is benign encapsulated neoplasm that arises from the
Schwann cells of a single nerve funiculus.
tumors are difficult to diagnose clinically and have been confused
with neurofibromas or other benign neoplasms.
present as a painless mass, occasionally with paresthesia and sensory
deficit. They are mobile in the plane transverse to the course of the
nerve and painful in rare cases. Nerve conduction studies may be
clinical importance of diagnosis when suspicion is present is related
to the surgical technique of schwannoma excision; in order to
preserve the nerve function, the mass requires careful enucleation
from the affected nerve. With an operating microscope and an
electrostimulator it is possible to show the tumor-nerve interface.
most significant morbidity of misdiagnosis of schwannomas is the risk
of nerve resection during the surgery.
tests such as US, CT, MRI can aid in diagnosis; the MRI can further
localize the extent of a solid mass but is very expensive and
difficult to propose when there are no neurological signs or symptoms
of nerve involvement.
of this clinical possibility is important to prevent, during the
surgery, the unfortunate resection of the nerve.
the diagnosis is made intraoperatively, so an appropriate index of
suspicion is necessary to include peripheral nerve tumors in the
differential diagnosis of an upper extremity mass.
Di Lorenzo, M.D.
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