Reporting a Case of Cervical Vertebral Body Primary Malignant Melanoma—A Rare Entity
G Krishna Kumar1, Chandrasekhar Chigurupalli1, Anandh Balasubramaniam1, BJ Rajesh1, Pooja Chavali2
1 Department of Neurosurgery, Yashoda Hospitals, Alexander Road, Shivaji Nagar, Secundrabad, Telangana, India
2 Department of Pathology, Yashoda Hospitals, Alexander Road, Shivaji Nagar, Secundrabad, Telangana, India
Correspondence Address:
Anandh Balasubramaniam
Department of Neurosurgery, Yashoda Hospitals, Alexander Road, Shivaji Nagar, Secundrabad - 500 003, Telangana
India
Source of Support: None, Conflict of Interest: None
CheckDOI: 10.4103/0028-3886.360928
Melanomas of vertebral body are usually metastatic lesions. Isolated vertebral body melanomas are rare may be due to unknown primary. Only threesuch cases havebeen reported in literature. We are reporting a 30-year-old female presented with progressive quadriparesis and bladder involvement. On evaluation, an extradural lesion at the C4-5 level with the destruction of C4 vertebral body and anterior in the prevertebral space seen with areas of blooming. The patient underwent surgery and biopsy was suggestive of melanoma. On further evaluation, we could find any other lesion in the body. The lesion can be either metastatic with unknown primary or primarily arising from vertebrae. Primary vertebral body melanomas are rare, surgical decompressions followed by immunotherapy may prolong the survival in this patients.
Keywords: Primary melanoma, unknown primary, vertebral melanoma lanomas with unknown primary hasand
Key Message: Melanomas with unknown primary have better prognosis and surgical decompression and immunotherapy good survival for patients.
In vertebral body, malignant melanoma commonly present as secondaries at the lumbosacral region. Malignant melanoma of vertebral body without any evidence of primary elsewhere is very rare.[1],[11] So far, in literature, there were three cases reported one in sacrum andtwo in lumbar region. We are reporting a case of cervical vertebral body primary malignant melanoma.
Case DetailsA 30-yr-old female patient with no known co-morbidities presented with weakness initially in her right shoulder gradually progressed to involve the right upper limb since 1 week. the last two days, her weakness progressed rapidly.She was wheel chair bound with bladder involvement when she presented to us. On examination, she was found to have asymmetric quadriparesis with predominant weakness in the right side with a motor power of 1/5 compared to the 4/5 of the left side. Her right upper limb was flaccid, while the rest of the limbs had grade 2 spasticity.
Patient was evaluated with contrast enhanced MRI and CT cervical spine. The CT was suggestive of lytic lesion of 4th cervical vertebral body with the destruction of the right side pedicle and facets with scalloping of the right lateral borders of the 5th and 6th cervical vertebral bodies with thinning of the right C5 and C6 pedicles. The lesion also widened the C4 and C5 transverse foramina [Figure 1]. MRI shows a T1 and T2 hyperintense, lobulated lesion of size 5 × 4 × 2 cm with few areas of blooming in GRE images with intra and extraspinal extensions along the C4-5 neural foramina with widening. There was no intradural extension of tumor. The lesion was extending into the prevertebral region between the sternocleidomastoid and longus coli muscles up to the C7 level without infiltrating it [Figure 2] and [Figure 3]. Based on MRI, the differential were malignant peripheral nerve sheath tumor, neurofibroma with bleeding, and vertebral hemangioma with hematoma.
Figure 1: NCCT cervical spine bone window (a) sagittal section shows destruction of C4 vertebral body (b) coronal section showing destruction of right transverse processes of C4, 5, and 6 and widening of foramens (c) axial section showing the destruction of C4 body and right transverse process with wideningFigure 2: MRI T2 sections (a-c) sagittal, coronal, and axial sections, respectively, showing T2 iso to hypointense lesions with the destruction of C4 vertebral body with extradural mass with cord compression with destruction of transverse process and pedicle with widening of foramenFigure 3: MRI T1 postcontrast imaging (a-c) coronal sections showing hyperintense lesion in the intermuscular plane extending into the C4 vertebral body and extradurally at the C4–5 level. (d) The sagittal section showing C4 destruction. (e-g) Axial images showing the tumor destroying the C4 body with the extradural part extending through the foramen and widening it with the destruction of transverse process and pediclesAnterior cervical approach was planned. A linear skin incision was made along the anterior border of the sternocleidomastoid muscle. The tumor was encountered below the sternocleidomastoid muscle which was firm and grayish brown in colour with central areas of bleed and necrotic tissue. The tumor was extending posteriorly into the C4 vertebral body. No intradural extension of the tumor was found. The intra spinal component of the tumor was removed completely andinsome areas, there were ill defined plane between the dura and tumor. Lesion was seen extending inferiorly in the pervertebral space along the longus coli muscle up to the C7 level and it was decompressed. The transverse foramen of C4 and C5 destroyed by the tumor and vertebral artery was identified and preserved. The right side C5 nerve root was thinned out. Our initial intraoperative impression was melanotic schwannoma but frozen was suggestive of melanoma. An expandable cage was implanted at the C4 level and C3-5 plate fixation was done.
Histopathology sections showed nests of anaplastic epitheliod cells showing variable cytoplasmic coarse brown pigment (melanin) with brisk mitotic activity. Numerous melanophages were seen interspersed within the tumor cells. IHC showed positivity for SOX10, HMB45 and S100. The melanophages were positive for CD68 and the features were suggestive of malignant melanoma [Figure 4].
Figure 4: Melanocytic tumor cells (a and b) along with extensive necrosis (c). The tumor cells show vesicular nucleus with prominent nucleoli (a). Melanocytes with intracytoplasmic melanin and melanophages are noted (b). [Hematoxylin –eosin 400×]A detailed evaluation was done postoperatively including PET-CT and no other lesions elsewhere in the body. he had improvement in motor power the right upper limb was 3/5 and on rest 5/5 at discharge. The postoperative MRI showed no evidence of tumor [Figure 5] and thepatient was planned for pembrolizumab immunotherapy.
Figure 5: Postoperative MR images (a and b) and sagittal sections of T1 and T2, respectively, showing no evidence of intraspinal and C4 leveltumor. (c) Axial section at C4 level with implant artifact DiscussionThe incidence of malignant melanoma is around 1–3% of all malignancies. It metastasizes to the draining lymph nodes and occasionally the adjacent skin first and then to the distant visceral sites. ung, brain, liver, bone marrow, and intestine are the common sites of metastasis in the descending order. In about 5–15% of cases, metastatic melanoma is detected in the absence of an identifiable primary tumor.[2],[12],[13]
Spinal metastatic lesions are rare with clinically evident incidence is of 4% and only 2.4%.Isolated vertebral body melanomas may be caused due to unknown primary. There are two possible hypothesis for vertebral body melanoma, one is that the primary lesion undergoes a spontaneous regression due to immunological response and the other is primary ectopic nevi in the lymph nodes.[1],[3],[4]
So far, in the literature, only cases have been reported which involve vertebral body melanoma without any primary lesions, the details of which are given in [Table 1]. All the three patients were male and our patient was female. They presented at and our patient presented at 30 years of age. Out of the three patients, two had lesions at the lumbar and one in sacral, while our patient had a cervical lesion. Out of three patients, two presented with radiculopathy and one with low back pain. Our patient presented with asymmetrical quadriparesis with bladder involvement. Of the three patients, twounderwent complete removal of tumor with instrumentation and the other patient had underwent open biopsy. Of the three patients, one who underwent open biopsy died after nine months due to lung metastasis. The other two patients survived for two years.[5],[6],[7] Our patient had underwent C4 corpectomy with expandable cage placement and plate fixation and now on immunotherapy.
Table 1: List of case reports on primary vertebral body malignant melanomaWhen malignant melanomas are diagnosed at an early stage, if the lesion can be excised completely then surgical excision can be curative to maximize long-term survival. If it was partially removed, then adjuvant local radiation therapy should be given. For locally advanced malignant melanoma, multimodality treatment should be considered includes surgical excision, immunotherapy, targeted therapy like mitogen-activated protein kinase pathway [MAPK] inhibition/KIT mutation, radiation therapy, and cytotoxic chemotherapy. The systemic therapy for metastatic melanoma includes checkpoint-inhibitor immunotherapy and targeted therapy against the MAPK.[8],[9],[14]
The 5-year survival rate of the patients with malignant melanoma with unknown primary lesion is around 30% which is better than those with metastatic melanoma who survive for s months.[4]
We hypothesize that the tumors of vertebral body may be considered as the primary central nervous system melanoma if no other foci are found upon evaluation. We all know that the notochord along with somites are the most significant structures responsible for the development of the future vertebral column.[10] The notochordal remnants may be the precursors for these tumors.
ConclusionSurgery remains the main treatment for vertebral body melanoma. Whenever possible, complete excision should be done followed by immunotherapy. These patients should be followed up lifelong with systemic screening for better survival.
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The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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