Surgical treatment for intramedullary spinal cord melanocytomas

Unsatisfactory Neurological Outcome in an Intramedullary Thoracic Intermediate-Grade Melanocytoma-Systematic Review and Illustrative Case

BACKGROUND

Intramedullary melanocytomas are exceedingly rare, with only twenty-four cases reported up to now. They present as local invasive tumors despite their benign biological behavior. Attempting a complete safe resection often results in severe post-operative neurological deficits, as in our case presented here.

METHODS

A systematic review was conducted across the PubMed and Scopus databases including studies published till February 2024.

RESULTS

A total of 19 studies were included, encompassing 24 cases. A similar distribution between sexes was noted (M:F 13:11), with ages ranging from 19 to 79 years. The thoracic segment was most affected, and intermediate-grade melanocytoma (19 cases) was the most common histotype. Radiographically, intramedullary melanocytomas usually appear as hyperintense hemorrhagic lesions peripheral to the central canal with focal nodular enhancement. Intraoperatively, they are black-reddish to tan and are tenaciously adherent lesions. In the sampled studies, IONM employment was uncommon, and post-operative new-onset neurological deficits were described in 16 cases. Adjuvant RT was used in four cases and its value is debatable. Recurrence is common (10 cases), and adjuvant therapies (RT or repeated surgery) seem to play a palliative role.

CASE PRESENTATION

A 68-year-old woman presented with a three-year history of worsening spastic paraparesis and loss of independence in daily activities (McCormick grade 4). An MRI revealed an intramedullary tumor from Th5 to Th7, characterized by T1-weighted hyperintensity and signs of recent intralesional hemorrhage. Multimodal neuromonitoring, comprising the D-Wave, guided the resection of a black-tan-colored tumor with hyper-vascularization and strong adherence to the white matter. During final dissection of the lesion to obtain gross total resection (GTR), a steep decline in MEPs and D-Wave signals was recorded. Post-operatively, the patient had severe hypoesthesia with Th9 level and segmental motor deficits, with some improvement during neurorehabilitation. Histopathology revealed an intermediate-grade melanocytoma (CNS WHO 2021 classification). A four-month follow-up documented the absence of relapse.

CONCLUSIONS

This literature review highlights that intramedullary T1 hyperintense hemorrhagic thoracic lesions in an adult patient should raise the suspicion of intramedullary melanocytoma. They present as locally aggressive tumors, due to local invasiveness, which often lead to post-operative neurological deficits, and frequent relapses, which overwhelm therapeutic strategies leading to palliative care after several years.

Intradural extramedullary meningeal melanocytoma: a case report and literature review

Primary meningeal melanocytomas are extremely rare, benign tumours arising from the leptomeninges. While they are considered to be benign lesions, there is potential for their growth and transformation into malignant melanomas. They are commonly found in the cervical spine, with a decreased incidence in the thoracic and lumbar regions. We present a case report of a 56-year-old man who presented to our unit with a 4-month history of lower limb weakness and a sensory level at T6. Magnetic resonance imaging shows an intradural extramedullary tumour. The patient underwent a thoracic debulking of the lesion with neurophysiological monitoring. Histopathology confirmed the diagnosis of melanocytoma of meningeal origin, with a low mitotic count. Our patient recovered well post-operatively with no complications. Surgical resection is an effective method to manage this tumour; however, adjuvant radiotherapy is advised due to the risk of recurrence and malignant transformation.

How Should We Treat Meningeal Melanocytoma? A Retrospective Analysis of Potential Treatment Strategies

BACKGROUND

Meningeal melanocytomas (MM) are rare primary melanocytic tumors of the leptomeninges with an incidence of 1:10,000,000. Until now, there has been only sparse information about this tumor entity. Here, we provide a meta-analysis of all cases published in the English language since 1972.

METHODS

A literature review was performed using PubMed and Web of Science. All published cases were evaluated for location, sex, age, therapeutic approach, and outcome. In total, we included 201 patient cases in our meta-analysis.

RESULTS

The majority of MM was diagnosed more frequently in men between the third and fifth decade of life. Surgery is the preferred therapeutic approach, and total resection is associated with the best outcome. Patients with partial resection or tumor recurrence benefit from adjuvant radiotherapy, whereas chemo- or immunotherapies do not improve the disease course. Malignant transformation was described in 18 patients. Of these, 11 patients developed metastasis.

CONCLUSIONS

We present the first retrospective meta-analysis of all MM cases published in the English language, including an evaluation of different treatment strategies allowing us to suggest a novel treatment guideline highlighting the importance of total resection for recurrence-free survival and characterizing those cases which benefit from adjuvant radiotherapy.

Primary Melanocytomas of the Spinal Cord: Case Studies and Rehabilitation Perspectives

Primary melanocytomas of the central nervous system are rare tumors arising from leptomeningeal melanocytes. Only 29 cases have been reported in the literature. Presenting symptoms may include insidious onset of back pain, slowly progressive neurologic deficits such as weakness and sensory changes, and bowel and bladder dysregulation. Advanced imaging including magnetic resonance imaging can be helpful in lesion localization but does not distinguish between primary and metastatic melanoma. In this case series, we present 3 patients with nontraumatic spinal cord injuries secondary to primary central nervous system malignant melanocytomas who were admitted to a single inpatient rehabilitation facility within a 12-month time frame. These cases highlight the importance of the rehabilitation team in the continuum of care for patients undergoing resection of primary melanocytomas of the spinal cord. The rehabilitation team should be involved in the preoperative counseling setting, immediately postoperatively, and in follow-up care to assess for signs of recurrence. A comprehensive multidisciplinary approach including physical and occupational therapists, rehabilitation nurses, rehabilitation neuropsychologists, and physiatrists is important for optimizing the function of these patients.

S-100-negative, GNA11 mutation-positive intramedullary meningeal melanocytoma of the thoracic spine: A radiographic challenge and histologic anomaly

Background:

Intramedullary melanocytomas are exceedingly rare and their management is largely based on case reports and small clinical series. They have characteristic imaging and histologic findings that can aid in their diagnosis. Genetic testing may be required for definitive diagnosis and management guidance in ambiguous cases.

Case Description:

We present the case of a thoracic intramedullary meningeal melanocytoma in a patient unable to undergo an MRI.

Conclusion:

This is the first reported S-100-negative case with genetic testing to support the diagnosis of a rare intramedullary melanocytoma.

[Primary pineal melanocytoma: clinical case and literature review]

Primary pineal melanocytomas are extremely rare pathologies and predominantly are clinically manifested by nonspecific symptoms of a pineal affect, which could be characteristic for tumors of different histological nature located in the same region. Also these tumors differ from other melanocytic tumors by their slow growth and relatively favorable clinical prognosis.

Spinal meningeal melanocytoma in a 5-year-old child: a case report and review of literature

Background

Meningeal melanocytoma is considered a rare lesion arising from leptomeningeal melanocytes. Nearly two thirds of meningeal melanocytomas were reported in the intracranial compartment and the remaining one third in the spine. Spinal melanocytomas can be extradural or intradural, with extradural variant being more common, and the majority of cases have been single reports.

Methods

A 5-year-old male presented with a 4-month history of non-radiating low back pain persistent at rest, with otherwise non-remarkable medical history. The patient was neurologically intact with no deficits. Preoperatively, routine laboratory investigations were non-remarkable. MRI imaging was done and showed a lesion at the level of T11 to L4, hyperintense on T1 and hypointense on T2 with homogenous contrast enhancement. Intraoperatively, the lesion was hemorrhagic, brownish, and rubbery in consistency attached to the ventral dura. Microscopic picture revealed dense cytoplasmic brown melanin pigments, with no significant mitoses or nuclear atypia. What is unique about our case is the age of the patient (5 years).

Results

To the best of our knowledge, after reviewing the literature, this is the youngest case to be reported.

Conclusions

SMM is an extremely rare tumor with a benign course. Complete surgical excision should be attempted. Age of presentation may be as young as in our case and the diagnosis of such a tumor should never be excluded in this early age group with persistent low back ache.

Intramedullary Melanocytoma of the Cervicothoracic Cord: Case Report and Review of Literature

Melanocytoma is rare pigmented tumor of the leptomeninges which arise from the neural crest. Intramedullary location of the tumor is extremely rare, and only a few case reports are available in the literature. We report a case of 35-year-old female with the entity who had a near total removal of the intramedullary tumor with good postoperative outcome. The available literature is reviewed.

[Intramedullary melanocytoma: a clinical case report and literature review]

The paper describes a rare clinical case of intramedullary melanocytoma, provides a detailed description of a pathomorphological study, and addresses the issues of differential diagnosis and surgical treatment.

Primary intramedullary melanocytoma in the cervical spinal cord: Case report and literature review

A 63-year-old man with right hemiparesis was found (on MRI) to have an expansive intramedullary tumorous lesion at the C2-C3 level. After complete neurosurgical tumor resection, the tumor was histologically categorized as an intermediate grade of intramedullary melanocytoma, an uncommon neoplasm. Based on this peculiar case and review of the literature, radical surgical resection appears to be the therapy of choice for intramedullary melanocytomas. However, their high recurrence rate and aggressive behavior suggest the need for close followup with serial MRI.

Intramedullary and retroperitoneal melanocytic tumor associated with congenital blue nevus and nevus flammeus: an uncommon combination of neurocutaneous melanosis and phacomatosis pigmentovascularis--case report

Neurocutaneous melanosis (NCM) is a rare condition characterized by central nervous system melanocytic tumors associated with congenital melanocytic nevi. Phacomatosis pigmentovascularis (PPV) is an association of vascular nevus with pigmentary nevus. Aberrant maturation of neural crest-derived cells is considered to be related to pathogenesis in both conditions. However, association of NCM and PPV has not been reported to the best of our knowledge. Melanocytoma, which usually involves the leptomeninges or spinal cord, is extremely rare in the retroperitoneum. We present here a case of a patient with NCM, PPV, and melanocytic tumors in the spinal cord and retroperitoneum, which were treated surgically. A 40-year-old woman had a 2-year history of dysesthesia and weakness in the left leg. History included congenital giant blue nevus-like lesion in the trunk, a port-wine stain in the sacral area, and Caesarean section performed 8 years before, when diffuse pigmentation in the peritoneum was noted. Magnetic resonance (MR) imaging of the spine revealed an intramedullary tumor at T10 level with paramagnetic signal characteristics. The spinal cord tumor was totally removed, and the histological diagnosis was melanocytoma. Three months later, a left retroperitoneal mass with histological features of melanocytic tumor was removed. Neither tumors recurred and the patient stays ambulatory 4 years after the surgery. Multiple subtypes of melanocytic tumors with distinctive features of NCM and PPV can develop simultaneously, mimicking malignant melanoma. Gross total resection of each tumor, when indicated, is beneficial.

Treatment of intramedullary tumors: analysis of surgical morbidity and long-term results

Object

Surgery of intramedullary tumors is established as the treatment of choice for these challenging lesions. This study presents a detailed analysis of risk factors for surgical morbidity and data on long-term results for intramedullary tumors.

Methods

Among 1317 patients with tumors of the spinal canal treated between 1980 and 2012, 278 patients with intramedullary tumors are presented. A total of 225 of these patients underwent 246 operations for treatment of 250 tumors. The mean patient age was 41 ± 17 years (range 3 weeks to 83 years). Patients underwent follow-up through outpatient visits and questionnaires with a mean follow-up of 41 ± 53 months. Tumors were subdivided into 3 groups: displacing tumors (Type A, n = 162), infiltrating tumors (Type B, n = 80), and nonproliferating tumors (Type C, n = 8). A gross-total resection (GTR) was attempted for every tumor except for Type C lipomas. Participating surgeons were divided into 3 groups according to the number of operations they performed. Short-term results were determined for individual symptoms and the modified McCormick Scale, whereas tumor recurrence rates were calculated with Kaplan-Meier statistics.

Results

Overall, 83.3% of Type A tumors underwent GTR compared with 22.5% of Type B and none in Type C. Gross-total resection rates increased throughout the study period and correlated significantly with surgical experience. A worsened neurological state after surgery was seen in 61% of patients. This deterioration was transient in 41.5% and was a common observation after GTR. Permanent morbidity (19.5%) was lowest after GTR and correlated significantly with surgical experience and the preoperative neurological state. Further analysis showed that patients with tumors of thoracic levels, tumor hemorrhages, and malignant and recurrent tumors were at a higher risk for permanent morbidity. In the long term, tumor recurrence rates for ependymomas and benign astrocytomas correlated significantly with the amount of resection. Long-term morbidity affected 3.7% with a postoperative myelopathy related to cord tethering at the level of surgery and 21.9% in form of neuropathic pain syndromes. The rate of postsurgical cord tethering could be lowered significantly by using pia sutures after tumor resection. Neuropathic pain syndromes were more common after surgery for tumors with associated syringomyelia or those located in the cervical cord.

Conclusions

Intramedullary tumors should be surgically treated as soon as neurological symptoms appear. Gross-total resection is possible for the majority of benign pathologies. Cervical tumors are associated with higher GTR and lower permanent morbidity rates compared with thoracic tumors. Surgery on intramedullary tumors should be performed by neurosurgeons who deal with these lesions on a regular basis as considerable experience is required to achieve high GTR rates and to limit rates of permanent morbidity.

Bifocal extra- and intradural melanocytoma of the spine: case report and literature review

BACKGROUND

Spinal melanocytoma is one of the most infrequent space-occupying lesions of the central nervous system. To the best of our knowledge, this is the first report of primary bifocal intradural melanocytoma of heterogeneous pathological grade to date.

CASE DESCRIPTION

We report the case of a 43-year old patient with primary bifocal melanocytoma, clinically and radiologically resembling benign schwannoma. The patient presented with myeloradiculopathy of the left C3 dermatome. Magnetic resonance imaging of the upper spine revealed two space-occupying lesions with paraspinal extension, initially diagnosed as neurofibroma. Definitive histopathological classification of both lesions was melanocytoma. Both tumours were only partially removed due to adherence to surrounding structures. The patient underwent stereotactic external beam irradiation (EBR). Follow-up at 1 year after surgery revealed no recurrence and the patient remained free of symptoms. The clinical, radiological and pathological features of this rare tumour entity are presented and the available literature is reviewed.

CONCLUSIONS

Intradural melanocytoma, although exceedingly rare, requires a thorough work-up to exclude malignant melanoma. With only two previous reports of multifocal melanocytoma published in the literature, standard therapy has not yet been established and complete surgical removal remains the modality of choice. Patients should be closely monitored to detect local recurrence or malignant degeneration. EBR may be considered in cases where total excision is not achievable and reduces risk of local recurrences.

MR imaging findings of the intraspinal meningeal melanocytoma: correlation with histopathologic findings

Our aim was to better understand and improve the accuracy of the preoperative diagnosis of intraspinal MM by a combined analysis of MR imaging and pathologic findings. All 5 patients had undergone unenhanced and contrast-enhanced MR imaging examinations. All tumor samples had immunohistochemical reactions to HMB-45, vimentin, S-100, EMA, and Leu-7 antibodies. All 5 cases were located in the intradural extramedullary compartment. Two cases had multifocal lesions, and 3 cases were solitary. Two cases showed homogeneously strong enhancement, and 3 cases showed moderate enhancement on contrast-enhanced T1WI. The tumor cells had positive reactions to HMB-45, vimentin, and S-100 antibodies. MR imaging plays an important role in the detection and diagnosis of intraspinal MM. Final diagnosis should be based on histopathology and IHC examinations.

Malignant transformation of intramedullary melanocytoma: case report

OBJECTIVE

Meningeal melanocytomas are low-grade primary melanocytic tumors with benign histological features and a favorable clinical prognosis. Transition from meningeal melanocytoma to primary melanoma of the central nervous system is exceptionally rare, with only 5 cases having been previously reported. Here, we discuss a case of malignant transformation of an intramedullary melanocytoma to primary melanoma and review the pertinent literature.

CLINICAL PRESENTATION

A 79-year-old woman presented with progressive paresis in the lower limbs followed by sphincter dysfunction. Magnetic resonance imaging scans disclosed an intramedullary lesion located at the T10-T11 level.

INTERVENTION

The patient underwent subtotal resection of an intermediate-grade melanocytoma. Two years later, the tumor recurred locally, and the patient underwent additional surgery to remove the intramedullary mass. The histological findings of the tumor were consistent with an intramedullary malignant melanoma.

CONCLUSION

The malignant transformation of melanocytic tumors of the central nervous system may occur years after surgical treatment, and its incidence remains unknown. Emphasis should be placed on the importance of careful and continued follow-up monitoring of the tumor.

Intramedullary spinal melanocytoma

Meningeal melanocytoma is a benign lesion arising from leptomeningeal melanocytes that at times can mimic its malignant counterpart, melanoma. Lesions of the spine usually occur in extramedullary locations and present with spinal cord compression symptoms. Because most reported spinal cases occur in the thoracic region, these symptoms usually include lower extremity weakness or numbness. The authors present a case of primary intramedullary spinal meningeal melanocytoma presenting with bilateral lower extremity symptoms in which the patient had no known supratentorial primary lesions. Gross total surgical resection allowed for full recovery, but early recurrence of tumor was detected on close follow-up monitoring, allowing for elective local radiation without loss of neurological function. Case reports of such tumors discuss different treatment strategies, but just as important is the close follow-up monitoring in these patients even after gross total surgical resection, since these tumors can recur.

Activating mutations of the GNAQ gene: a frequent event in primary melanocytic neoplasms of the central nervous system

Primary melanocytic neoplasms of the central nervous system (CNS) are uncommon neoplasms derived from melanocytes that normally can be found in the leptomeninges. They cover a spectrum of malignancy grades ranging from low-grade melanocytomas to lesions of intermediate malignancy and overtly malignant melanomas. Characteristic genetic alterations in this group of neoplasms have not yet been identified. Using direct sequencing, we investigated 19 primary melanocytic lesions of the CNS (12 melanocytomas, 3 intermediate-grade melanocytomas, and 4 melanomas) for hotspot oncogenic mutations commonly found in melanocytic tumors of the skin (BRAF, NRAS, and HRAS genes) and uvea (GNAQ gene). Somatic mutations in the GNAQ gene at codon 209, resulting in constitutive activation of GNAQ, were detected in 7/19 (37%) tumors, including 6/12 melanocytomas, 0/3 intermediate-grade melanocytomas, and 1/4 melanomas. These GNAQ-mutated tumors were predominantly located around the spinal cord (6/7). One melanoma carried a BRAF point mutation that is frequently found in cutaneous melanomas (c.1799 T>A, p.V600E), raising the question whether this is a metastatic rather than a primary tumor. No HRAS or NRAS mutations were detected. We conclude that somatic mutations in the GNAQ gene at codon 209 are a frequent event in primary melanocytic neoplasms of the CNS. This finding provides new insight in the pathogenesis of these lesions and suggests that GNAQ-dependent mitogen-activated kinase signaling is a promising therapeutic target in these tumors. The prognostic and predictive value of GNAQ mutations in primary melanocytic lesions of the CNS needs to be determined in future studies.

Primary intramedullary melanocytoma of the spinal cord: case report

OBJECTIVE

The authors report 2 cases of primary intramedullary spinal melanocytomas in 2 patients who presented with lower extremity numbness and/or weakness.

CLINICAL PRESENTATION

Magnetic resonance imaging of the spine, thoracic laminectomy, and histological examination revealed the diagnosis.

TECHNIQUE

Microscopic and immunohistochemical analysis revealed the diagnosis of primary melanocytoma.

CONCLUSION

Melanocytomas of the spine are rare lesions without distinctive imaging characteristics and pose a preoperative diagnostic challenge. A review of the relevant literature and clinical behavior of this uncommon tumor entity is provided.