Therapeutic options for meningeal melanocytoma. Case report

A rare case of multifocal craniospinal leptomeningeal melanocytoma: A case report and scoping review

Introduction

Leptomeningeal melanocytomas are rare tumours originating from neural crest derived melanocytes. They are usually solitary and presentation with multifocal meningeal melanocytoma is very rare and indicative of potentially more aggressive behaviour. This case report and scoping review sought to evaluate the presentation, and key radiological features that can help differentiate multifocal meningeal melanocytoma from other differentials and provide a discussion of the key management and prognostic points once these tumours are diagnosed.

Case presentation

A 26 year old male presented with neck pain radiating to both shoulders and subjective weakness in left shoulder movement. MRI demonstrated a large enhancing C2-C3 intradural-extramedullary lesion with further lesions at the T7/T8 level, left cerebellopontine angle and midline suprachiasmatic region. Whilst the imaging appearances were initially thought be indicative of a phacomatosis such as NF2-related schwannomatosis, surgical excision of the cervical tumour confirmed a melanocytic tumour of leptomeningeal origin, consistent with multifocal meningeal melanocytoma. Patient made a good post-operative recovery and remains under half yearly radiological surveillance, with repeat MRI 6 months after surgery demonstrating subtle growth of the untreated intracranial and spinal lesions.

Literature review and conclusions

This is the first description, to our knowledge, of a multifocal meningeal melanocytoma associated with both cerebellopontine angle and suprasellar lesions. This case and included scoping review highlight the need to consider this rare diagnosis whenever multifocal craniospinal lesions are encountered, and the need to consider aggressive management through surgical resection and adjuvant craniospinal radiotherapy once these tumours are diagnosed.

Surgical Management of Primary Thoracic Epidural Melanoma

In this study, we reported one of the first cases where a rare robotic-assisted platform with neuronavigation technology and carbon-fiber-polyetheretherketone (CF/PEEK) screws is employed to surgically treat multilevel thoracic primary spinal epidural melanoma. A 67-year-old male presented with left upper thoracic pain. His magnetic resonance imaging (MRI) of the thoracic spine revealed a dumbbell-shaped left epidural mass at the T2-3 level. Partial resection was performed due to tumor growth into the vertebral bodies and patient discretion for minimal surgery. The patient's neurological conditions improved postoperatively, with reduced reported symptoms of pain and numbness. Postoperative imaging showed evidence of appropriate spinal stabilization. Patient underwent stereotactic body radiation therapy (SBRT), and no adverse events were reported. This case reflects one of the first examples of treating thoracic epidural melanoma with the use of robotic-assisted navigation. Further prospective studies are needed to determine the efficacy of robot-assisted navigation for patients with primary spinal malignant melanoma which may open the possibility of surgery to once presumed non-operative patients.

Recurrent spinal meningeal melanocytoma at lumbar spine level: a case report

INTRODUCTION

Spinal meningeal melanocytoma is an extremely rare tumour with an estimated annual incidence of 1 per 10 million people. It usually arises from the intradural extramedullary compartment at the cervical levels. Although these tumours are histologically benign, they may behave aggressively. Local recurrence could occur even after total tumour excision.

CASE REPORT

We report a case of a 33-year-old Asian male who developed progressive weakness and numbness of the bilateral lower extremities as well as urinary retention five years after complete tumour resection of lumbar spinal meningeal melanocytoma. Magnetic resonance imaging of the lumbar spine revealed a mass with thecal sac compression which was hypointense on T2-weighted images and hyperintense on T1-weighted images. The patient underwent total tumour removal. Histologic examination was compatible with recurrent meningeal melanocytoma. After a 4-week inpatient rehabilitation programme, he was able to ambulate without assistance and to do clean intermittent catheterisation for micturition on a regular basis.

DISCUSSION

This is the first reported case of intradural extramedullary meningeal melanocytoma located at the lumbar region. Clinicians should consider the possibility of these rare tumours at any level of the spine, and be aware of sphincter dysfunction in addition to motor and sensory deficits of extremities.

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.

Stereotactic radiosurgery for intracranial primary melanocytomas

OBJECTIVE

The role of stereotactic radiosurgery (SRS) in the management of recurrent and residual intracranial primary melanocytomas (PMC) remains unclear. The aim of this study is to evaluate the safety and efficacy of SRS in the management of these rare tumors.

METHODS

One patient treated with SRS in our institution for an intracranial PMC was retrospectively identified. Additionally, a systematic review of English articles using MEDLINE was performed to identify studies reporting on treatment and tumor characteristics and patient outcomes following SRS-management of intracranial PMC.

RESULTS

Including our institution's patient, a total of 13 patients (11 males and 2 females) met the inclusion criteria and were analyzed. The median age at SRS treatment was 49 years [Interquartile range (IQR) 27]. At a median follow-up of 24 (IQR 48) months, the aggregate local tumor-control rate was 76.9%. Progression occurred in three patients and was managed with repeat SRS (1/13) or salvage resection (2/13). One case of malignant transformation to melanoma leading to leptomeningeal dissemination and death was noted.

CONCLUSION

SRS appears to be a reasonable treatment option for recurrent and residual melanocytomas. A higher prescription dose might be reasonable in the treatment of intermediate grade or recurring PMC. Close longitudinal follow up for recurrence or malignant transformation of melanocytomas after SRS is recommended.

Primary sellar melanocytoma

PURPOSE

We present an up-to-date review of all published cases of sellar melanocytoma, a benign melanocytic neoplasm arising from melanocytes present in the leptomeninges surrounding the pituitary.

METHODS

Both the Medline and Embase databases were searched for case reports or case series of patients with a sellar mass consisting of melanocytes.

RESULTS

All 14 identified patients developed symptoms due to compression of the surrounding structures. Symptoms included pituitary dysfunction and visual impairment. All patients received a transsphenoidal resection as first-line treatment. The diagnosis is made on pathological examination but deciding whether a sellar melanocytic tumor is best classified as a melanocytoma or a melanoma is not straightforward.

DISCUSSION

Genetic analyses can help differentiate between central nervous system origin and metastasis of a cutaneous melanoma with the presence of a GNAQ and GNA11 mutations or a BRAF mutation, respectively. First choice treatment is complete resection, and in case of incomplete resection or recurrence additional radiotherapy is advised.

Primary intramedullary melanocytoma presenting with lower limbs, defecation, and erectile dysfunction: A case report and review of the literature

BACKGROUND

Primary intramedullary melanocytoma is an exceedingly rare type of primary melanocytic tumor in the central nervous system. Unfortunately, primary intramedullary melanocytoma lacks specificity in clinical symptoms and imaging features and there is currently no standard strategy for diagnosis or treatment.

CASE SUMMARY

A 52-year-old male patient suffered from weakness and numbness involving the bilateral lower limbs for 18 mo, and defecation and erectile dysfunction for 6 mo. Furthermore, these symptoms started to worsen for the last 3 mo. Preoperative magnetic resonance imaging (MRI) revealed an intramedullary tumor located at the T9-T10 level. In subsequently surgery, the maximal safe resection extent approached to 98%. The lesion was confirmed to be melanocytoma by pathological examination. In addition, the possibility of original melanocytoma outside the spinal cord was excluded after the examination of the whole body. Therefore, a diagnosis of primary intramedullary melanocytoma was established. The patient refused to accept radiotherapy or Gamma Knife, but MRI examination on July 28, 2020 showed no sign of development. In addition, on April 10, 2021, the recent review showed that the disorder of defecation and lower limbs improved further but erectile dysfunction benefited a little from the surgery.

CONCLUSION

After diagnosing intramedullary melanocytoma by postoperative pathology, the inspection of the whole body contributed to excluding the possibility of metastasis from other regions and further suggested a diagnosis of primary intramedullary melanocytoma. Complete resection, adjuvant radiation, and regular review are critical. In addition, maximal safe resection also benefits prognosis while the tumor is difficult to be resected totally.

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.

Nivolumab as adjuvant treatment for a spinal melanocytoma: A case report

RATIONALE

Meningeal melanocytoma is a rare benign melanocytic tumor of the central nervous system. We report for the first time a case of meningeal melanocytoma treated with immunotherapy.

PATIENT CONCERNS

A 70-year-old man with no medical history was admitted to the Emergency Room. He suffered from a motor and sensory deficit in his left lower limb and a bilateral upper arm neuralgia.

DIAGNOSES

A contrast-enhanced magnetic resonance imaging (MRI) was performed. It showed a C7-T1 bleeding intramedullary tumor. Laminectomy was decided and performed. The results of the pathologic examination showed a melanocytic tumor harboring GNAQ mutation. Meningeal melanocytoma was the final diagnosis.

INTERVENTIONS

The patient was treated with 10 radiotherapy sessions and 6 cycles of nivolumab. A year later, the patient experienced neuralgia again with severe pain and an increasing sensory motor deficit. He underwent a second surgery that was incomplete. As the tumor kept growing, he received temozolomide. But the 6th cycle had to be interrupted due to bedsore infection in the hip area.

OUTCOMES

Disease progression finally led to the patient's death 3 years after diagnosis.

LESSONS

This case report is the first about a patient with meningeal melanocytoma treated with immunotherapy. Treatment based on biomolecular mutations will probably change spinal melanocytoma therapeutic approach in the next few years.

Recurrent Meningeal Melanocytoma of Cervical Spine: A Rare Case

Melanocytomas of the central nervous system are rare benign or intermediate grade localized melanocytic tumors. Despite its benign nature, it can follow a locally aggressive course with propensity to recur. We present the case of a 29 years old female who presented with a recurrent lesion in cervical spine and rapidly progressing quadriparesis. On examination, there was loss of power in right-sided extremities and reduction in sensations in left-sided extremities. Magnetic resonance imaging spine revealed a homogeneously enhancing intradural extramedullary dumbbell-shaped mass lesion at C4/5 level with extension through right C4 neural foramina to the extraforamina space, causing severe spinal cord compression. Intraoperatively, bluish-colored tumor was identified along with underlying hematoma. Gross total excision of the tumor was done. Tumor was received in the histopathology department in multiple black-colored fragments. Microscopically, a heavily pigmented tumor was seen with the sheets and nodules of polygonal cells with large nuclei and prominent nucleoli. Differentials considered were meningeal melanocytoma and malignant melanoma. On immunohistochemistry, the tumor cells showed diffuse positivity for HMB 45 and S100. Ki 67 index was around 1%. On radiological review, the tumor was fairly well circumscribed and did not infiltrate the adjacent tissues. There was no evidence of any lesions elsewhere in the body. Considering these features, the tumor was diagnosed with meningeal melanocytoma. Postoperatively, there was significant immediate improvement in quadriparesis and patient could walk with minimal support.

Identification of a Novel BRCA1 Alteration in Recurrent Melanocytoma Resulting in Increased Proliferation

Primary meningeal melanocytomas are rare tumors of the central nervous system. Although they are considered benign neoplasms, some reports describe recurrent rates up to 45%. Little is known about their genetic and epigenetic landscape because of their infrequency. Even less has been described about markers with prognostic value. Here we describe a patient who developed a primary meningeal melanocytoma, suffered 3 recurrences in a period of 6 years and died of the tumor. The genetic and epigenetic changes explored confirmed GNAQ mutation as an initiating event. We found an epigenetic alteration of GSTP1, a feature that has recently been described in meningiomas, from the beginning of the disease. In addition, there was loss of heterozygosity in BRCA1 beginning in the second recurrence that was linked to an increase in the proliferation index; this suggested a progression pathway similar to the one described in uveal melanomas. These findings underscore the necessity of further research focused on these tumors.

8-Year Follow-up for Woman with Spinal Meningeal Melanocytoma in S1 Nerve Root: Case Report and Literature Review

BACKGROUND

Primary melanocytic neoplasms in the central nervous system are rare lesions arising from leptomeningeal melanocytes. These lesions produce neural deficits that resemble those of a meningioma or a schwannoma radiologically.

CASE DESCRIPTION

A tumor around the left S1 root with an extension into the left paraspinal compartment was identified in a 32-year-old female with persistent left leg pain for 6 months. The tumor was hyperintense on T1-weighted image and hypointense on T2-weighted image with a homogeneous enhancement. The clinical features, radiologic presentations, treatment choice, and pathologic characteristic were illustrated. The treatment outcome was compared with those reported in the previous literature. The tumor was en-bloc resected with the S1 nerve root reserved. Grossly, the tumor was a soft, capsulated, well-circumscribed, black pigmented lesion. Immunohistochemistry revealed that the tumor cells were positive for HMB-45, S-100 protein, and vimentin. The patient's symptoms were greatly relieved postoperatively. No signs of local recurrence were observed.

CONCLUSIONS

Spinal meningeal melanocytoma inside the nerve root is rare and benign. It is difficult to diagnose and often misdiagnosed as schwannoma or meningioma. HMB-45 has been suggested as a significant marker for the diagnosis of meningeal melanocytoma. Complete surgical resection is recommended as the primary treatment. Radiotherapy, chemotherapy, and other treatments can be selected as adjuvant therapies, but their effects are controversial. The recurrence and metastasis rates also remain unclear.

Primary meningeal melanocytoma of the cerebellopontine angle associated with ipsilateral nevus of Ota: A case report

BACKGROUND

Cerebellopontine angle represents a complex anatomical area of the brain. A cerebellopontine angle lesion could be a vestibular schwannoma, meningioma, epidermoid cyst, or less likely, arachnoid cyst, metastasis, lower cranial nerves schwannoma, lipoma, hemangioma, paraganglioma, or vertebra-basilar dolichoectasia. Primary meningeal melanocytoma is a rare neoplasm, especially when it occurs at the cerebellopontine angle. Nevus of Ota (aka oculodermal melanocytosis) is a hyperpigmentation along the distribution of the ophthalmic and maxillary branches of trigeminal nerve; it occurs due to entrapment of melanocytes at the upper third of the dermis. It may not present at birth and may show up at puberty.

CASE DESCRIPTION

We describe a case of primary meningeal melanocytoma of the cerebellopontine angle associated with nevus of Ota in a 46-year-old male patient presented with 7-day history of left arm weakness and vertigo. Computed tomography and MRI showed right-sided cerebellopontine angle mass, which was resected. Histopathology confirmed the meningeal melanocytic lesion and revealed its nature.

CONCLUSION

Primary meningeal melanocytoma of the brain is a rare but benign tumor; the association between meningeal melanocytoma and nevus of Ota is also rare and possibly explained by their common embryonic origin from neural crest cells. There are six cases reported so far in literature including our case for meningeal melanocytoma associated with nevus of Ota.

Orbital melanocytoma: When a tumor becomes a relieving surprise

Purpose

Melanocytomas are rare pigmented tumors that arise form melanocytes and have been reported in the central nervous system. Orbital melanocytomas "also known as blue nevus" are rarely reported. The occurrence of choroidal melanoma and orbital melanocytomas has never been described.

Observations

This is a case of orbital melanocytoma in a 34 year old female who presented with left proptosis and ecchymosis. She has the right eye enucleated to treat a large choroidal melanoma, 6 years earlier. Orbital metastasis was suspected. After orbital imaging and systemic evaluation, incisional biopsy was planned yet the mass could be totally excised and it turned out to be melanocytoma. The condition was not associated with nevus of Ota and the patient is not known to have any predisposing condition for melanocytic lesions.

Conclusion and importance

Melanocytoma and malignant melanoma share the same cell of origin. The benign course, the well differentiated cells, absence of anaplasia and the positive reaction to Human Melanoma Black-45 (HMB-45) and S-100 proteins established the diagnosis of the former. Such diagnosis was a relief for this one eyed patient.(HMB-45:human melanoma black-45).

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.

Supratentorial intermediate grade meningeal melanocytoma with intratumoral bleed in the background of neurocutaneous melanosis: Report of an unusual case and review of literature

Primary melanocytic tumours of the central nervous system (CNS) are rare. According to the WHO classification (2007), these tumours include diffuse leptomeningeal melanosis, melanomatosis, melanocytoma, and primary CNS melanoma. Meningeal melanocytoma, most commonly seen in the infratentorial compartment and cervical spinal cord, is a benign primary melanocytic neoplasm. Primary CNS melanoma, on the other hand, represents the malignant end of the spectrum. Intermediate grade melanocytoma is a rare histological subtype of primary meningeal tumours and is characterised by the clinicopathological features between the two extremes. Neurocutaneous melanosis (NCM) is a rare phacomatosis characterised by melanotic lesions on the skin and leptomeninges. Leptomeningeal manifestation in NCM may be observed either in the form of diffuse leptomeningeal melanosis or primary CNS melanoma. Melanocytomas are focal lesions and their association with NCM is extremely rare. In this report, we present an unusual case of NCM accompanied by right frontal intermediate grade melanocytoma with intratumoral bleeding in a 17-year-old boy. A brief literature review is also presented.

Multifocal melanocytoma of the posterior fossa and subcutaneous scalp in the absence of neurocutaneous melanosis

BACKGROUND

Primary leptomeningeal melanocytic neoplasms of the central nervous system are rare. Multifocal lesions typically occur in the setting of cutaneous melanosis. We present the first report of a posterior fossa melanocytoma and subcutaneous melanocytoma of intermediate grade in the absence of cutaneous melanosis.

CASE DESCRIPTION

We present the case of a 22-year-old male with decreased hearing on the right side, ataxia, nausea, vomiting and a scalp mass. Magnetic resonance imaging (MRI) demonstrated occipital and cerebellopontine (CP) angle masses. The patient underwent gross total resection of the scalp mass and subtotal resection of the CP angle mass. Pathologic examination revealed melanocytoma with intermediate grade. The patient underwent stereotactic radiosurgery to the residual CP angle tumor. This case represents, to the author's knowledge, the first report associating a posterior fossa melanocytoma with a subcutaneous melanocytoma of intermediate grade in the absence of cutaneous melanosis.

CONCLUSION

This case introduces the first report of a new variant of multifocal melanocytoma which is not confined to the central nervous system.

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.

Primary melanocytic tumors of the central nervous system: a review with focus on molecular aspects

Primary melanocytic tumors of the central nervous system (CNS) represent a spectrum of rare tumors. They can be benign or malignant and occur in adults as well as in children, the latter often in the context of neurocutaneous melanosis. Until recently, the genetic alterations in these tumors were largely unknown. This is in contrast with cutaneous and uveal melanomas, which are known to harbor distinct oncogenic mutations that can be used as targets for treatment with small-molecule inhibitors in the advanced setting. Recently, novel insights in the molecular alterations underlying primary melanocytic tumors of the CNS were obtained, including different oncogenic mutations in tumors in adult patients (especially GNAQ, GNA11) vs. children (especially NRAS). In this review, the focus is on molecular characteristics of primary melanocytic tumors of the CNS. We summarize what is known about their genetic alterations and discuss implications for pathogenesis and differential diagnosis with other pigmented tumors in or around the CNS. Finally, new therapeutic options with targeted therapy are discussed.

Intermediate-grade meningeal melanocytoma associated with nevus of Ota: a case report and review of the literature

Meningeal melanocytomas are rare melanin-producing tumors that are often found to be benign. However, a small subset of these tumors can present as intermediate-grade melanocytomas (IGMs) that have histopathological features that are between those of benign melanocytomas and malignant melanomas. IGMs have the potential to recur and metastasize or progress to a more histologically high grade melanoma. Melanocytomas appear to differ from primary and metastatic melanoma by their prolonged clinical course and they appear to have different driver mutations (i.e. mutation of GNAQ gene). The association of a meningeal melanocytoma with nevus of Ota is extremely rare. To our knowledge, there have been only 10 reported cases of synchronous occurrence and only one of the cases involved an IGM. We report the second case of intermediate-grade meningeal melanocytoma that is associated with congenital nevus of Ota. Histopathological work-up confirmed the intermediate grade of the lesion and a driver GNAQ mutation was identified consistent with previous reports.

Primary Meningeal Melanocytoma in the Left Temporal Lobe Associated with Nevus Ota: a Case Report and Review of the Literature

BACKGROUND

Primary melanocytic neoplasms of the central nervous system are rare lesions arising from melanocytes of the leptomeninge that are found at highest density underneath the brain stem and along the upper cervical spinal cord. Thus most reported cases of meningeal melanocytomas are located in the posterior fossa and the spinal cord, and presentation of a supratentorial tumor is rare.

METHODS

A 19-year-old man presented with a headache and seizure at our department. Neurological examinations were otherwise normal. On physical examination he had asymptomatic, bluish, speckled, and well-demarcated hyperpigmented macules on the left midface extraorally. A left temporal space-occupying lesion was seen on magnetic resonance imaging. The mass was hyperintense on T1-weighted images and isointense on T2-weighted images. Enhancement was shown on contrast-enhanced magnetic resonance imaging (MRI). The preoperative diagnosis was meningioma.

RESULT

Gross complete resection was performed. Pathological studies led to the diagnosis of meningeal melanocytoma World Health Organization (WHO) grade I. The patient received oncologic consultation. Because total resection of the tumor was achieved and its histopathologic grade was benign (WHO grade I), radiotherapy was not advised for the patient and he followed up every 6 months. No tumor was seen on follow-up MRI one year after surgery.

CONCLUSION

Presentation of meningeal melanocytoma in the supratentorial compartment is rare, and its combination with nevus Ota has been reported in very few cases. Although this lesion is benign, it might behave aggressively. Complete surgical resection of the lesion is the preferred therapeutic option.

From the radiologic pathology archives: mass lesions of the dura: beyond meningioma-radiologic-pathologic correlation

Meningioma is the most common mass involving the dura, making it number one in the differential diagnosis for any dural-based mass; however, a variety of other neoplastic and nonneoplastic lesions also involve the dura. Knowledge of the dural anatomy can provide clues to the various processes that may involve this location. The neoplastic processes include both benign and malignant lesions such as hemangiopericytoma, lymphoma, solitary fibrous tumor, melanocytic lesions, Epstein-Barr virus-associated smooth muscle tumors, Rosai-Dorfman disease, and metastatic lesions. The nonneoplastic processes include infectious and inflammatory entities such as tuberculosis and sarcoid, which may mimic mass lesions. In some cases, neoplasms such as gliosarcoma may arise peripherally from the brain parenchyma, appearing dural-based and even inciting a dural tail. Many of these share similar computed tomographic, magnetic resonance imaging, and angiographic characteristics with meningiomas, such as a dural tail, increased vascularity, avid enhancement, and similar signal characteristics; however, knowledge of the patient's age, gender, and underlying conditions and certain imaging characteristics may provide valuable clues to recognizing these lesions. For example, in the population with human immunodeficiency virus infection, Epstein-Barr virus-associated smooth muscle tumors should be included in the differential diagnosis for dural-based lesions. The surgical course and prognosis for these lesions vary, and knowledge of the variety of lesions that involve the dura, their imaging appearances, and their clinical features assists in narrowing the radiologic differential diagnosis and optimizing patient treatment.

Intramedullary melanocytoma of thoracic spine: A rare case report

Melanocytomas are present in leptomeninges and arise from neural crest during early embryonic development. They are a rare entity and usually occur in the thoracic spine and infratentorial region. We report a 32-year-old female with meningeal melanocytoma of D9-10. Magnetic resonance imaging revealed an intramedullary spinal tumor at D9-D10. Intraoperatively, the tumor was greyish-black in color with moderate vascularity, and was adherent to the cord. The clinical differential diagnoses included cavernoma and melanocytoma. On microscopic examination, the lesion showed sheets of cells with marked pigment deposition, which was obscuring the cellular morphology. The pigment was confirmed to be melanin by Masson's Fontana stain. Immunohistochemistry was performed, which showed positivity for HMB-45, S-100, Vimentin and Melan-A. The cells were negative for cytokeratin, epithelial membrane antigen, Glial fibrillary acidic protein and neuron-specific enolase. Mib-1 labeling index was less than 1%. In view of the lack of nuclear atypia, mitoses, necrosis and low Mib-1-labeling index along with immunohistochemistry profile, the diagnosis of Melanocytoma was made. Melanocytomas are rare pigmented tumors of the spinal cord and posterior cranial fossa. They are benign in nature, but can also be locally aggressive. Melanocytic lesions of the nervous system are to be differentiated from metastatic melanomas and also tumors showing melanin pigment deposition like schwanomma, paraganglioma, medulloblastoma and various gliomas.

Primary meningeal melanocytoma of the anterior cranial fossa: a case report and review of the literature

BACKGROUND

Primary meningeal melanocytoma is a rare neurological disorder. Although it may occur at the base of the brain, it is extremely rare at the anterior cranial fossa.

CASE PRESENTATION

A 27-year-old man presented with headache and diplopia at our department. Fundoscopy showed left optic nerve atrophy and right papilledema consistent with Foster-Kennedy syndrome. Neurological exams were otherwise normal. A left frontal irregular space-occupying lesion was seen on magnetic resonance imaging (MRI), and enhancement was shown on contrast-enhanced computed tomography (CT) scan. CT angiography (CTA) revealed vascular compression around the lesion. Prior to surgery, meningioma was diagnosed and gross tumor removal was performed. On postoperative pathohistological exam, the tumor proved to be a meningeal melanocytoma, WHO grade I. No skin melanoma was found. After surgery, the patient received radiation therapy. No tumor was seen on follow-up MR images six months after surgery. The patient was well after two and a half years, and there was no tumor recurrence on the follow-up CT.

CONCLUSIONS

This case of primary meningeal melanocytoma located at the anterior cranial fossa is very rare. Although primary meningeal melanocytoma is benign, it may behave aggressively. Complete surgical resection is curative for most cases. Radiation therapy is important to prevent relapse of the tumor, especially in cases of incomplete surgical resection.

Primary cerebellopontine angle melanocytoma: review

Introduction Primary cerebellopontine angle melanocytomas (PCPAMs) are very rare. Their natural history and prognosis are not fully understood. We reviewed the literature and add a new case to analyze PCPAM's presentation, radiological features, and outcome of treatment.

Methods We performed a literature review using Medline, Embase, PubMed, and Cochrane databases. We searched for melanocytoma, melanoma, and pigmented tumors in the posterior cranial fossa and CPA to identify PCPAM. We have also searched our institution's neuro-oncology database.

Results We identified 23 PCPAM from the literature and one case of our own. The mean age at presentation was 44.4 years with slight male preponderance. PCPAM presented with cerebellopontine angle (CPA) syndrome with or without hydrocephalus. Preoperative diagnosis was difficult; they appeared hyperintense on T1 and isointense on T2 magnetic resonance imaging (MRI) and enhanced with gadolinium. However, the final diagnosis was only made by immunohistochemical examination. Total surgical resection of PCPAM was associated with prolonged survival while subtotal excision was associated with frequent recurrence.

Conclusion PCPAM are very rare and should be considered in the differential diagnosis of all CPA lesions that appear hyperintense on T1 and isointense on T2 MRI images. Patients with PCPAM should undergo total surgical resection to avoid fatal recurrences.

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.

Primary thoracic epidural melanoma : a case report

A 68-year-old woman with progressive paraparesis and altered sensation lasting approximately five days was admitted to our clinic. Magnetic resonance imaging (MRI) revealed an advanced stage T7-8 epidural mass ventral to the spinal cord, which was believed to be a metastatic tumor considering the patient's age. A highly enhanced epidural mass and pedicle appeared during the MR scan. However, the pathologic findings were compatible with the diagnosis of a primary meningeal melanocytic tumor. Primary epidural melanomas are extremely rare lesions. This case was finally diagnosed as a primary thoracic spinal epidural melanoma.

Pigmented lesions of the central nervous system: radiologic-pathologic correlation

Pigmented lesions of the central nervous system (CNS) are a diverse group of entities that run the gamut from benign to malignant. These lesions may be well circumscribed or diffuse, and their imaging appearances are influenced by the degree of melanin content as well as the presence or absence of hemorrhage. Pigmented lesions include primary melanocytic lesions of the CNS and metastatic melanoma, as well as other CNS neoplasms that may undergo melanization, including schwannoma, medulloblastoma, and some gliomas. Primary melanocytic lesions of the CNS arise from melanocytes located within the leptomeninges, and this group includes diffuse melanocytosis and meningeal melanomatosis (seen in neurocutaneous melanosis), melanocytoma, and malignant melanoma. Primary melanin-containing lesions of the CNS must be differentiated from metastatic melanoma because these lesions require different patient workup and therapy. Absence of a known primary malignant melanoma helps in the differential diagnosis, but an occult primary lesion outside the CNS must be sought and excluded. Pigmented lesions of the CNS are uncommon, and knowledge of their imaging characteristics and pathologic features is essential for their identification.

Intermediate grade meningeal melanocytoma of cervical spine

BACKGROUND

Meningeal melanocytoma is a rare, benign melanotic tumor of the leptomeninges, which occurs anywhere in the cranial or spinal regions but most commonly in supratentorial and thoracic spine regions. The literature on this entity consists of case reports; therefore, there is no agreement on the most effective therapy of this tumor, although total excision seems to be the best therapeutic option.

CASE HISTORY

We report a 17-year-old girl with intermediate grade meningeal melanocytoma involving the C6 nerve root with spinal cord compression resulted in progressive tetraparesis. Clinical and radiological examinations suggested the possibility of an intradural extramedullary solid mass. The tumor was removed subtotally through cervical laminotomy followed by rapid improvement of most neurological deficits. This tumor was unusual because of its very hyperintense homogenous signal on T1-weighted images, invasion of the arachnoid membrane, and extension into the neural foramina. Black dots on the surface of the cord were thought to represent an organized blood clot until the frozen section suggested a melanocytic tumor.

DISCUSSION

We discuss the distinction of meningeal melanocytoma from other melanocytic tumors of the leptomeninges.

CONCLUSION

Melanocytic tumors should be considered in the differential diagnosis when a hyperintense lesion of the leptomeninges is identified on T1-weighted images or a very dark mass similar to charcoal or organized hematoma is found in the surgical field. The best management is complete tumor resection, but radiotherapy is reserved in cases of subtotal resection and multiple lesions. Locally aggressive nature of tumor and possibility of recurrence warrant regular follow-up.

35-year-old woman with progressive bilateral leg weakness

A 35-year-old woman presented with one month's history of progressive bilateral leg weakness and altered sensation. There had been no pain. She had noted urinary frequency and constipation in the previous two weeks. On examination, the patient had diffuse lower extremity weakness (2-3/5), with a T6 sensory level to pain and temperature sensation. MRI demonstrated a T4-5 intradural mass ventral to the spinal cord, with an enhancing dural tail, consistent with meningioma. At surgery an intradural, extramedullary, firm, black neoplasm was encountered, which invaded the ventral dura and elevated and distorted the spinal cord. The mass was removed, leaving only microscopic invasion of the ventral dura. There was no bone invasion. Serial sections revealed a homogeneous black tumor without necrosis. H&E stained sections showed an occasionally fascicular tumor of melanocytes and small round blue tumor spindle cells with melanin pigmentation and 1-2 mitotic figures per 10 high-powered fields. The nuclei are generally oval-shaped and elongated, with prominent nucleoli. Necrosis, hemorrhage, and nuclear and cellular pleomorphism are not present and mitotic figures are rare. Immunohistochemical staining was positive for S-100 and HMB-45. MIB-1 labeling averaged 1-2%. A diagnosis of primary meningeal melanocytic tumor was made. Primary meningeal melanocytic tumors (PMMTs) are rare; fewer than 100 cases have been described. PMMTs of the CNS consist of a spectrum of tumors ranging from well-differentiated melanocytoma to its overtly malignant counterpart, melanoma. Intermediate grade melanocytomas (IMGs) are the least common variant, comprising about 10% of PMMTs reported. IGMS occur in the spinal leptomeninges and intracranially in approximately equal proportions. IGMs are more cellular than the well-differentiated variant, with 1-3 mitotic figures per 10 HPFs and MIB-1 labeling of <6%. By contrast, melanomas contain more mitotic figures (3-15 per 10 HPF) and MIB-1 labeling rates up to 15%. Once metastasis, including drop metastasis from pigmented medulloblastomas, have been excluded, the differential includes pigmented meningiomas and schwannomas (solitary or as part of Carney complex), as well as other pigmented CNS tumors such as ependymoma and pineoblastoma and systemic diseases such as lymphoma . . . For primary CNS melanocytic neoplasms, complete tumor resection is preferred, as it leads to cure of well-differentiated and intermediate-grade melanocytomas and most melanomas. Radiotherapy is recommended for incomplete resection of IMGs and melanomas; the recurrence potential of low-grade melanocytomas is less clear and watchful waiting may be employed, since recurrent tumors may be treated surgically prior to radiation. Two months after surgery, the patient had normal sensation and strength. She was given focused radiotherapy to the region of the ventral thecal sac to 40 cGy. At one year following surgery, the patient's neurological examination is normal and she remains free of residual disease by MR examination.

Meningeal melanocytoma

BACKGROUND

Meningeal melanocytoma was first described over 30 years ago as a benign tumour derived from melanocytes. Since then, data suggest that its mode of presentation is variable without a clear predilection for any particular site in the neuroaxis. Although classified as a benign tumour, this tumour shows a marked tendency towards reduced survival following subtotal resection and transformation over time in a limited number to malignant melanoma. Incomplete resection of these tumours without postoperative radiotherapy has only a 42% 5-year survival rate. Its classification as a benign tumour should be revised, given the published 5-year survival data.

ILLUSTRATIVE CASE

We report a fatal case of meningeal melanocytoma in the cerebello-pontine angle in a 10-year-old child. This case exemplifies the vascular nature of these lesions even with minimal vascular blush on angiography. An updated literature search is presented, the results of which highlight the need for close follow-up and adjuvant treatment following subtotal resection.

Supratentorial meningeal melanocytoma mimicking a convexity meningioma

OBJECTIVE AND IMPORTANCE

Meningeal melanocytomas are rare benign neuro-ectodermal tumors arising from melanocytic cells in the leptomeninges. These leptomeningeal melanocytes are found at highest density underneath the brain stem and along the upper cervical spinal cord. Thus, most reported cases of meningeal melanocytomas are located in the posterior fossa and the spinal cord, respectively.

CLINICAL PRESENTATION

We report on the rare case of a 55-year-old male patient with a large supratentorial meningeal melanocytoma mimicking a convexity meningioma and a smaller, similarly dura based lesion in the posterior fossa.

INTERVENTION

Tumor control to date was achieved by surgery of the large lesion and radiosurgery of the small lesion.

CONCLUSION

Complete tumor resection may be advantageous and second or recurrent lesions may be managed by repeat surgery or stereotactic radiosurgery.

Spinal meningeal melanocytoma. Report of two cases and review of the literature

The authors report on two patients with spinal meningeal melanocytoma and review the literature on this lesion. One case is particularly interesting because of the lesion's thoracic intramedullary localization. Meningeal melanocytoma is a benign but locally aggressive lesion and is very rarely associated with spinal localizations. This patient presented with paraparesis. Clinical and radiological examinations suggested the possibility of an intramedullary solid tumor. Thoracic laminectomy, posterior myelotomy, and tumor resection were performed; the mass was totally removed. The patient suffered no additional neurological deficit. During a 3-year follow-up period in which radiotherapy was not performed, the lesion did not recur. Total excision of the tumor is the best therapeutic option.