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CASE REPORT
Kor J Spine 6(1):40-42, 2009
Primary Malignant Melanoma of the Cervical
Spinal Nerve Root
- A Case Report -
Byoung Ill Roh, M.D., Jin Woo Hur, M.D., Jong Joo Rhee, M.D., Hyun Koo Lee, M.D.
Department of Neurosurgery, Cheongju Saint Mary's Hospital, Cheongju, Korea
Primary malignant melanoma of the nervous system is a rare disease, and accounts for only 1% of melanoma cases.
Primary melanomas on the spinal nerve root, particulary the cervical spinal nerve root, are extremely rare. Only a few
cases of primary melanoma arising from the spinal nerve root have been reported. We report our experience with a case
of primary malignant melanoma of the cervical spinal nerve root.
Key Words: Malignant melanoma ․ Cervical spine
INTRODUCTION
Malignant melanoma of the central nervous system is well
known as a result of the relatively high frequency of cerebral
metastases. Primary melanotic tumor of the nervous system have
also been described, as have benign melanocytic tumors 3,6,12) .
Primary malignant melanoma of the nervous system is a rare
disease, and accounts for only 1% of melanoma cases. Melanocytoma
is distinguished from melanoma based on the histological
findings and clinical behavior. In the spinal region,
several reports and studies of meningeal melanocytoma, melanotic
schwannoma, and intramedullary melanoma have been
reported, but only a few cases of primary malignant melanoma
limited to cervical spinal nerve root have been described.
spinal brachial plexus area that appeared to extend from the
C6-7 neural foramen (Fig. 1). A T1 weighted enhanced image
showed a heterogenous enhancing mass lesion. Unexpectedly,
CASE REPORT
A 65-year-old man visited our hospital due to severe left side
neck pain and numbness and sensory change on his left arm
and hand for 1 month prior. His symptoms were not improved
by conservative management. We identified a soft palpable
mass on the left side of his neck at the supraclavicular
area. On neurological examination, he presented with hypesthesia
and numbness on the left C6 and C7 dermatomes. He
did not complain any motor weakness. Cervical spinal MRI
showed a large (5.9×3.2×3.9 cm), oval mass on the left para-
Fig. 1. A-D, Coronal (A), sagittal (B), and axial (C) cervical
spinal images with gadolinium enhancement showing a large
oval mass on the left paraspinal brachial plexus area.
Scattered low signal intensity is evident on the T2 weighted
image (D).
● Received: February 27, 2009 ● Accepted: March 12, 2009 ● Published: March 31, 2009
Corresponding Author: Jin Woo Hur, M.D.
Address of reprints: Department of Neurosurgery, Cheongju St. Mary's Hospital, 589-5 Jujungdong, Sangdang-gu, Cheongju, 360-568, Korea
Tel: 82-32-43-219-8152, Fax: +82-43-211-7925, E-mail: somalh@naver.com
40 Kor J Spine 6(1) March 2009

Primary Malignant Melanoma of the Cervical Spinal Nerve Root
Fig. 2. Malignant melanoma composed of highly anaplastic cells with hyperchromaic nuclei, abundant
eosinophilic cytoplasm, and melanin pigments (×200) (A). Positive findings for vimentin, s-100 protein,
and HMB-45 (×200) (B).
scattered low signal intensity lesions within the mass were
identified on the T2 weighted image; these were thought to be
due to the presence of melanin, later (Fig. 1). Preoperative clini
cal and radiographic diagnosis was nerve sheath tumor such as
neurofibroma or schwannoma. An operation using the anterolateral
approach at left supraclavicular area between the carotid
sheath and sternocleidomastoid muscle was performed. The
bulk of the mass was removed. At surgery an encapsulated pitch
black mass was found. It was large, firmly attached to brachial
plexus and C6-7 neural foramen. Pathological examination confirmed
the diagnosis of malignant melanoma. It is composed of
highly anaplastic cells with hyperchromaic nuclei, abundant
eosinophilic cytoplasm, and melanin pigments. And it presented
positive findings for vimentin, s-100 protein, and HMB-45
(Fig. 2). The tumor had a high Ki-67 labeling index (35%). The
patient’s symptoms improved totally after the operation. The
patient wanted to transfer to other hospital for more thorough
evaluation on post-op 11th day. So we could not proceed adjuvant
therapy and follow-up observation.
DISCUSSION
The cell of origin of melanotic tumors involving the spinal
nerve root can be either a melanocyte, a Schwann cell, or an
uncharacterized cell type 11) . Melanocytes are melanin-producing
cells that arise from the neural crest during embryogenesis, and
migrate to the skin, mucous membranes, and central nervous
system. Tumors arising from melanocytic cells (primary and
metastatic melanoma) and Schwann cells (melanotic nerve sheath
tumors) have a common embryological origin in the neural
crest 8,11) .
Because of rarity of primary melanoma in spinal nerve root,
the diagnosis can be difficult. Radiological studies may not be
specific. Magnetic resonance imaging may offer some indication
of a melanotic lesion, melanin can show a hyperintense
or isointense signal on T1 weighted images and decreased signal
on T2 weighted images 7,9,12) .
The pathological differential diagnosis of primary melanoma
includes metastatic melanoma, melanocytoma, melanotic schwannoma,
and melanotic clear-cell sarcoma. Melanocytoma lacks
anaplastic features such as necrosis, significant mitotic activity,
and pleomorphism, in contrast with primary melanoma. The
characteristics of primary malignant melanomas are considerable,
including nuclear pleomorphisms leading to large and bizarreshaped
tumor cells with multinucleated giant cells 13) . A high
mitotic rate, coagulative necrosis and hemorrhage are also commonly
found in primary malignant melanoma 1,13) . Immunohistochemical
staining is also helpful for differentiation. Significant
s-100 protein expression without the expression of epithelial
membrane antigen supports the diagnosis of a schwannoma
or melanoma 5,13) . Negative immunoreactivity for Leu-7
rules out schwannoma whereas the detection of HMB-45 favors
the diagnosis of a melanocytic tumor 5,13) .
Schneider et al. 11) reported a case of primary melanoma arising
from the L3 spinal nerve root that was treated by wide
en-bloc resection. Skarli et al. 12) reported a similar case of primary
malignant melanoma arising in a cervical spinal nerve
root that did not recur or metastasize over 3 years without adjuvant
chemotherapy or radiation therapy after surgical operation.
Also Kwon et al. 4) reported a case of primary malignant melanoma
of the C7 nerve root in 2004 that was treated with adjuvant
radiation therapy.
Because of the rarity of these lesions, the prognosis and proper
adjuvant therapy (chemotherapy, radiotherapy) have not been
established yet.
It is important to differentiate primary melanoma from metastasis.
The prognosis for patients with metastatic melanoma to
central nervous system is dismal, with a life expectancy of less
than 1 year in most studies 2,4,10) . In contrast, primary melanoma
has long-term survival and better prognosis than metastatic lesion.
Kor J Spine 6(1) March 2009 41

BI Roh, et al.
In our case, we could not find any other tumor mass or pigmented
skin lesion through radiological and physical examinations.
CONCLUSION
Primary CNS melanoma is a rare disease entity and melanomas
arising from and limited to the spinal nerve roots are
extremely rare. At present, the prognosis and optimal treatment
(surgery, radiotherapy, chemotherapy) of primary melanoma of
the spinal nerve root have not been established. More cases
and further follow-up is needed to establish guidelines for the
treatment of this rare disease entity.
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42 Kor J Spine 6(1) March 2009