ESPRAS Quadrennial Congress 2022, Porto, Portekiz, 5 - 07 Ekim 2022
SCHWANNOM İN THE ARM: CASE REPORT
Dokuz Eylul University Faculty of Medicine, Department of Plastic, Reconstructive and
Aesthetic Surgery, Izmir
İNTRODUCTİON
Schwannoma is a hard, well-circumscribed, encapsulated and slow-growing benign tumor of
the nerve sheaths. It was first described by Verocay in 1908. It can be seen at any age, it is
most common between the ages of 20-50 and the female/male ratio is 2:1. It is most
common in the head and neck, but 20% of Schwannomas originate from peripheral nerves.
Schwannomas constitute 12-19% of upper extremity tumors. They are mostly seen on the
flexor sides of the extremities, especially in the wrist and elbow regions. The ulnar nerve is
the most common location in the upper extremity. These tumors can easily be confused with
lipomas, neurofibromas, hemangiomas, and synovial cysts.
Since the symptoms of peripheral nerve schwannoma often coincide with nerve
entrapments, they can easily be misdiagnosed. Symptoms appear by pressing on the mass or
surrounding tissues, there is no medical treatment for schwannomas, the treatment is the
complete removal of the mass.
CASE REPORT
With no known systemic disease, a 62-year-old male patient was admitted to us after
multiple external center applications upon noticing progression in the size of the nodular
lesion located distal to the right arm for about 3 years.The patient had no known history of
trauma.During the examination performed by us, a painful minimal mobile skin nodular
lesion measuring 1* 1 cm was detected by palpation on the radial side of the 1/3 distal part
of the right arm.On examination, no motor defects were detected while describing minimal
hypoesthesia in the radial nerve tract.Magnetic resonance imaging performed in the radial
nerve tract distal to the right arm with a size of 17* 12 mm is compatible with schwannoma
possible mass lesion was observed.
After obtaining written informed consent from the patient, the operation was performed
under general anesthesia with pneumatic tourniquet control. After a longitudinal 3 cm
incision made on the lateral arm, the lateral intermuscular septum was dropped. After
crossing the septum, the radial nerve was reached. It was observed that the mass was
located in the middle of the nerve and expanded the radial nerve anteriorly and posteriorly.
It looked moderately hard, yellowish, and encapsulated. The nerve sheath was opened and
the tumor was completely removed without damaging the nerve. The mass was well-
circumscribed and easily distinguishable from the surrounding tissues.
The mass was separated for pathological examination. No sensory or motor deficits were
detected in the radial nerve tracing of the patient, who did not have any problems at the
wound site. The patient was discharged on the first postoperative day with good recovery. In
the pathology report, compact areas (Antoni A) consisting of fusiform cells with palisadic
pattern and tumoral structure formed by loose and hypocellular areas (Antoni B) were
observed. In Antoni A areas, cells with eosinophilic cytoplasm, unclear borders, and
elongated nuclei were observed and the lesion was reported as schwannoma.
Immunohistochemical S-100 staining supported the diagnosis. The patient reported that all
his complaints were resolved immediately. At the end of the first week, she was completely
asymptomatic and returned to her daily activities.
DİSCUSSİON
Schwannoma accounts for 5% of soft tissue tumors in adults. It is also more common in the
upper extremity than the lower extremity. It mostly involves the ulnar, median and radial
nerves in the upper extremity. While 30-70% of all extremity schwannomas have pain
complaints, 20% have paresthesia complaints. Our patient presented with the complaint of
numbness in the fingers, and the lesion was palpated in the physical examination of our
patient. The possibility of peripheral nerve sheath tumor should be considered in the
differential diagnosis of superficial tissue lesions in the extremities. Although Tinel's test
positivity and paresthesia are seen in most of these tumors, lipoma, neurofibroma, ganglion
cyst and xanthoma should also be considered in the differential diagnosis. Ultrasonography
may be our first choice in evaluating such superficial lesions, but the most effective imaging
method is magnetic resonance imaging. It is not possible to differentiate the lesion from
malignant-benign with imaging. Size over 5 cm, irregular borders, surrounding edema,
homogeneous necrotic areas, presence of calcification and inactivity on palpation are criteria
that increase the suspicion of malignancy. Schwannomas rarely show malignant
transformation and are encapsulated and well-circumscribed tumors. They rarely recur after
total excision and post-excision chemotherapy and radiotherapy are not recommended.
In conclusion, peripheral nerve schwannomas are not very common. Sometimes they can
cause entrapment neuropathies. Therefore, a careful neurological and physical examination
will enable such lesions to be noticed. Careful dissection during surgery will minimize nerve
damage.
Keywords: Schwannoma, radial nerve, arm