Meningeal melanocytoma. Report of a case and a historical comparison

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.

Definitive radiotherapy for meningeal brainstem melanocytoma: a case report

Meningeal melanocytomas are rare, benign tumours of the central nervous system arising from the melanocytes of the leptomeninges. First-line treatment consists of either gross or subtotal resection with or without radiotherapy. However, given the sensitive locations of these tumours, alternative treatment options such as definitive radiotherapy may be warranted in patients deemed high-risk or without accessible tumours. A 67-year-old male presenting with spastic gait, frequent falls, and vertical gaze palsy was diagnosed with a 2.4 cm primary meningeal melanocytoma arising from the interpeduncular fossa. Given the critical tumour position within the brainstem, definitive radiotherapy was recommended. He received fractionated stereotactic radiotherapy (FSRT) to a total dose of 54 Gy in 27 fractions, resulting in a gradual improvement in gait and ocular range of motion. Follow-up imaging over the next three years revealed largely stable disease and an increase in edema with mild upper extremity weakness that improved with steroids. He was followed for three years and expired four years after treatment due to pneumonia. For patients unable to receive surgical resection, definitive RT may provide local control with minimal morbidity.

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 Meningeal Melanocytoma Located in the Craniovertebral Junction: A Case Report and Literature Review

Primary meningeal melanocytoma is a rare benign tumor in the central nervous system (CNS), comprising less than 0.1% of all intracranial tumors. A 44-year-old man presented with occipital headache, nausea, and vomiting. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a well-defined intradural extramedullary mass lesion at the craniovertebral junction (CVJ). Gross total removal was achieved, and the patient improved symptomatically. The pathologic findings were consistent with meningeal melanocytoma. No tumor recurrence was seen on follow-up MRI two years after surgery. Cases of primary meningeal melanocytoma located at the CVJ are rare. The preoperative differential diagnosis of meningeal melanocytoma from meningioma is sometimes difficult because of their similar appearance on CT and MRI. Complete surgical removal is curative for most cases. We present a case of gross total removal of a meningeal melanocytoma located in the CVJ with references to the literature.

Primary sellar melanocytoma: pathological, clinical and treatment review

BACKGROUND

Sellar melanocytomas represent a small subgroup of primary melanocytic tumors. They arise from melanocytes located in the meningeal lining of the sellar floor or in the diaphragma sellae and this location is very uncommon. Usually, sellar melanocytomas are benign and slow-growing tumors with a high likelihood of recurrence.

PURPOSE

To our knowledge, due to the rarity of this condition, there are no guidelines regarding their diagnosis and treatment in the medical literature to date. We have developed a narrative review, analyzing the available studies regarding primary sellar melanocytomas reported in the medical literature. We have found ten papers on this topic and all of them are case reports. In all patients, tumor diagnosis was performed after the occurrence of neurological symptoms, in particular progressive visual loss or endocrinological disorders. The diagnosis is difficult, and it requires several preoperative and postoperative investigations, but histological examination is crucial.

CONCLUSIONS

Transsphenoidal surgery is the first-choice treatment. In case of tumor's recurrence or regrowth, the role of radiation therapy and chemotherapy is not entirely clear.

A cellular blue nevus with pigmented epithelioid melanocytoma-like pattern on the ipsilateral upper arm associated with a congenital plaque-type blue nevus on the hand

A 36-year-old man presented with a subcutaneous nodule on the right upper arm. A small nodule had developed 8 years earlier, and grew in size, accompanied by a tingling sensation and numbness. In addition, he had a bluish irregular patch on the right hand since birth, which crossed from the palm to the dorsal hand. Skin biopsies from the hand showed a heavily pigmented melanocyte proliferation in the dermis with perieccrine, perivascular, and perineural involvement, and a diagnosis of congenital plaque-type blue nevus was made. The tumor on the arm was located closely along the median nerve, and was observed as a large black pedunculated round tumor. Histopathologically, the tumor on the arm consisted of densely packed tissue with nevoid cells without atypia in the larger nodular part, and heavily pigmented spindle and epithelioid melanocytes in the slender stalk area, which was diagnosed as cellular blue nevus with pigmented epithelioid melanocytoma-like pattern. Next-generation sequencing revealed GNAQ mutations in the hand lesion, and in the lesions on the arm. This case suggests that the areas of skin following the same neural distribution of a congenital plaque-type blue nevus on the extremities should be followed up for secondary changes.

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.

Diagnostic Clue of Meningeal Melanocytoma: Case Report and Review of Literature

In this report, the patient was pre-diagnosed as meningioma before surgery, which turned out to be meningeal melanocytoma. Hence, we will discuss the interpretation of imaging and neurological statuses that may help avoid this problem. A 45-year-old man had increasing pain around the neck 14 months prior to admission. His cervical spine MR imaging revealed a space-occupying, contrast-enhancing mass within the dura at the level of C1. The neurologic examination revealed that the patient had left-sided lower extremity weakness of 4+, decreased sensation on the right side, and hyperreflexia in both legs. Department of Neuroradiology interpreted CT and MR imaging as meningiom. The patient underwent decompression and removal of the mass. We confirmed diagnosis as meningeal melanocytoma through pathologic findings. Afterwards, we reviewed the patient's imaging work-up, which showed typical findings of meningeal melanocytoma. However, it was mistaken as meningioma, since the disease is rare.

Primary scattered multifocal melanocytomas in spinal canal mimicking neurofibromatosis

BACKGROUND CONTEXT

Meningeal melanocytoma is an extremely rare pigmented tumor derived from leptomeningeal melanocytes. By and large, it is considered to be a well-differentiated and slow-growing benign lesion. Generally, meningeal melanocytomas are solitary lesions, and the occurrence of the primary multifocal form in the central nervous system is exceedingly rare; it has been previously reported in only six cases.

PURPOSE

The present report illustrates a 41-year-old woman with primary multifocal meningeal melanocytoma in the spinal canal. Contrary to earlier reports, the tumors presented with a scattered appearance mimicking neurofibromatosis.

STUDY DESIGN

This study is a case report and review of literature.

METHODS

On admission, the cerebral magnetic resonance images of the patient were normal, whereas the spinal magnetic resonance images showed scattered multifocal nodules mimicking neurofibromatosis. Surgical resection of the responsible lesions was scheduled. In addition to this case presentation, relevant previous reports were reviewed, and the challenging diagnosis, management, and prognosis of meningeal melanocytoma are discussed.

RESULTS

Gross total resection of the two largest lesions was achieved, and histopathological examinations confirmed the diagnosis. Despite the benign histopathological findings, the patient had an aggressive clinical course. On follow-up at 18 months after surgery, she succumbed to the disease.

CONCLUSION

Clinicians should be alert to a potential aggressive clinical course of meningeal melanocytoma, despite its benign histopathological nature. Of particular note is multifocality and diffuse leptomeningeal hyperpigmentation, which may suggest a poor prognosis. A combined treatment including surgical resection and adjuvant radiotherapy should be considered, and long-term close follow-up is necessary.

Primary meningeal melanocytoma of the sellar region: review of the literature and differential diagnosis with special reference to angiographical features

PURPOSE

Primary intracranial melanocytomas are rare neoplasms, especially in the sellar region. Intracranial melanocytoma is usually a dural-based tumor, fed by dural arterial branches in a manner similar to meningioma. Primary sellar melanocytoma may be misdiagnosed as hemorrhagic pituitary macroadenoma, spindle cell oncocytoma, and intrasellar meningioma. These tumors differ in some radiological respects, but are difficult to differentiate preoperatively.

METHODS

Only five cases of primary sellar/suprasellar melanocytic tumors, excluding melanomas have been reported thus far. In this paper, we report an instructive new case of a 31-year-old woman presenting with a 2-year history of amenorrhea and an intrasellar mass with suprasellar extension, suggestive of hemorrhagic pituitary adenoma.

RESULTS

Transsphenoidal surgical excision was difficult due to extensive bleeding from the lesion, and at the time, the tumor could not be diagnosed histopathologically. Six years later, we operated again because of tumor regrowth. Angiography revealed a hypervascular tumor, which was fed from the dorsal sellar floor. We had difficulty resecting the tumor, but achieved total removal. Our case had typical radiographic characteristics of melanocytoma, revealed by both magnetic resonance imaging and angiography. However, it was difficult to reach a final diagnosis. Further histopathological examination, including immunohistochemical and ultrastructural studies, was helpful for diagnosis of melanocytoma.

CONCLUSIONS

Primary sellar melanocytic tumors are derived from melanocytes in the meningeal lining of the sellar floor or in the diaphragm sellae, based on both embryological assumptions and the clinical findings of our case. We discuss the problems of differential diagnosis and management of primary sellar melanocytic tumors.

Primary atypical melanocytoma arising from the cavernous sinus in a child

INTRODUCTION

Primary melanocytic lesions of the central nervous system originate from leptomeningeal melanocytes, with a spectrum ranging from well-differentiated benign meningeal melanocytomas to malignant melanomas. Atypical melanocytomas are borderline tumors, which have clinical and pathological characteristics between benign melanocytomas and malignant melanomas. Melanocytomas are rare in children and infrequently arise from the cavernous sinus. Approximately five patients with such an origin site have been reported.

MATERIALS AND METHODS

We report a 15-year-old girl with an atypical melanocytoma arising from the cavernous sinus. She underwent partial resection of the tumor and postoperative gamma knife surgery (GKS). She is stable 39 months after surgery.

CONCLUSION

We discuss the first pediatric case with an intracranial atypical melanocytoma arising from the cavernous sinus.

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.

Orbital melanocytoma completely resected with conservative surgery in association with ipsilateral nevus of Ota: report of a case and review of the literature

BACKGROUND

Melanocytomas are rare pigmented primary lesions of the central nervous system arising from melanocytes of leptomeninges. They occur most frequently in the posterior fossa, Meckel's cave, or along the cervical and thoracic spinal cord. Orbital melanocytomas have been rarely reported. Nevus of Ota is a melanocytic lesion that can be associated with cutaneous and meningeal melanocytic neoplasms.

METHODS AND RESULTS

We describe a case of an orbital melanocytoma associated with ipsilateral Nevus of Ota. A 28-year-old man presented with proptosis and an ipsilateral congenital facial melanocytic lesion (Nevus of Ota). After imaging evaluation, a retro-orbital mass was discovered. A needle biopsy was performed and the diagnosis of melanocytoma rendered. The patient underwent complete surgical excision of the lesion.

CONCLUSION

In order to make the correct diagnosis and to choose the appropriate therapy, it is important to be aware of this rare presentation and its association with Nevus of Ota.

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.

Spinal meningeal melanocytoma with benign histology showing leptomeningeal spread: case report

Meningeal melanocytoma is a rare benign tumor with relatively good prognosis. However, local aggressive behavior of meningeal melanocytoma has been reported, especially in cases of incomplete surgical resection. Malignant transformation was raised as possible cause by prior reports to explain this phenomenon. We present an unusual case of meningeal melanocytoma associated with histologically benign leptomeningeal spread and its subsequent aggressive clinical course, and describe its radiological findings.

Unusual tonsillar herniation in meningeal melanocytoma: a case report

Meningeal melanocytoma is a primary melanocytic neoplasm with certain MR and immunohistochemical characteristics worthy to note. In a 38-year-old man with a complaint of headache for a couple of years and recently added nausea, vomiting, diplopia, progressive visual blurring and hearing loss, magnetic resonance imaging (MRI) was remarkable for T1 shortening of leptomeninges and certain nodules in precontrast study. Subsequent contrast-enhanced MR imaging of the brain and spine revealed enhancement in the basal cisterns extending throughout the spinal canal. Contrast-enhanced MRI revealed diffuse enhancement in the basal cisterns extending throughout the spinal canal. Immunohistochemical analysis on one of the intraspinal nodules proposed leptomeningeal melanocytoma. The characteristic shortening of T1 and T2 relaxation times in MRI as a result of the paramagnetic stable free radicals that exist within melanin, often suggests a diagnosis of a melanocytic leptomeningeal process. Moreover, there are unique immunohistochemical characteristics for these varied lesions. In appropriate clinical settings, certain radiologic findings, especially both T1 and T2 shortening in nodular CNS lesions should propose meningeal melanocytoma.

Spinal meningeal melanocytoma

Primary melanotic meningeal neoplasms are extremely rare lesions and benign forms are even rarer though with better prognosis than the malignant ones. We describe a 40-year-old male with a history of gradually progressive weakness of both lower limbs with normal bowel, bladder control, and an intradural mass measuring 1.5×1.0 cm on radiologic investigations. The lesion was surgically excised. Histopathologic examination revealed heavily melanin-pigmented cells, nuclei with reticulogranular chromatin and small nucleoli, moderate amount of eosinophillic cytoplasm with indistinct cell boundaries, and symplasmic appearance. A probable diagnosis of meningeal melanocytoma was made. The diagnosis was confirmed on immunohistochemical analysis which revealed strongly positive expression of HMB-45 in the tumor cells. Vimentin and S-100 were also diffusely positive while neuron specific enolase showed focal and patchy positivity; however, epithelial membrane antigen was distinctly negative.

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.

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.

Primary melanocytic neoplasms of the central nervous system

Primary melanocytic neoplasms of the central nervous system (CNS) are rare lesions arising from melanocytes of the leptomeninges. They include diffuse leptomeningeal melanocytosis or melanomatosis, melanocytoma and primary malignant melanoma. We have reviewed the English literature regarding these lesions, which consists of case reports and a small number of larger case series. The presenting features, radiological, surgical and histological findings are reviewed, as are current management options and prognosis. We also present illustrative case reports of diffuse leptomeningeal melanocytosis and primary melanoma of the CNS.

Multifocal meningeal melanocytoma: a new pathological entity or the result of leptomeningeal seeding?

Meningeal melanocytoma is a rare benign CNS tumor derived from the leptomeningeal melanocytes. Although unusual, malignant transformation with leptomeningeal seeding into the brain or spinal cord may occur years after the initial diagnosis. The authors report a unique case of multifocal benign meningeal melanocytoma involving both cerebellopontine angles and the thoracic spinal cord, with associated diffuse leptomeningeal hyperpigmentation. They review the literature relevant to this topic and discuss the radiological and pathological features of this disease as well as its treatment options.

Intraventricular occurrence of a melanocytoma

Melanocytomas are rare tumors of the central nervous system that are believed to arise from leptomeningeal melanocytes. A young girl presented with a contrast-enhancing cystic mass in the temporal horn of the left lateral ventricle. Microsurgical resection of a black-colored vascular tumor supplied by the anterior choroidal artery was performed. Appropriate immunohistochemical staining and electron microscope evaluations were used to confirm the pathological diagnosis. The patient made an excellent recovery; follow-up imaging revealed no recurrent or residual tumor. This is the first documented primary occurrence of a melanocytoma in an intraventricular location. The intraventricular occurrence of this tumor suggests that melanocytes may migrate into the choroidal fissure and may infrequently undergo neoplastic proliferation in that location. This case contains implications for the differential diagnosis of intraventricular tumors.

Surgical treatment for intramedullary spinal cord melanocytomas

Spinal meningeal melanocytomas are rare lesions that are histologically benign and can behave aggressively, with local infiltration. The authors present their experience with intramedullary spinal cord melanocytomas consisting of 3 cases, which represents the second largest series in the literature. A retrospective chart review was performed following identification of all spinal melanocytomas treated at the author's institution, based on information obtained from a neuropathology database. The charts were reviewed for patient demographics, surgical procedure, clinical outcome, and long-term tumor progression. Three patients were identified in whom spinal melanocytoma had been diagnosed between 1989 and 2006. The patients' ages were 37, 37, and 48 years, and the location of their tumor was C1-3, T9-10, and T-12, respectively. All 3 had complete resection with no adjuvant radiotherapy during follow-up periods of 16, 38, and 185 months, respectively. One patient demonstrated a recurrence 29 months after resection and the other 2 patients have demonstrated asymptomatic recurrences on imaging studies obtained at 16 and 38 months following resection. With these cases added to the available literature, the evidence strongly suggests that complete resection is the treatment of choice for spinal melanocytomas. Even with complete resection, recurrences are common and close follow-up is needed for the long term in these patients. Radiation therapy should be reserved for those cases in which complete resection is not possible or in which there is recurrence.

Orbital melanocytoma

PURPOSE

To report a case of intermediate grade meningeal melanocytoma presenting as a recurrent orbital mass.

INTRODUCTION

Melanocytomas are rare, primary, pigmented tumors of the central nervous system, usually presenting as well-circumscribed, encapsulated, solid masses in the posterior cranial fossa and at the spinal region, often attached to the underlying dura. Orbital manifestation is rarely encountered.

METHODS

Case report with computed tomography scan, magnetic resonance imaging, histology, and immunohistochemistry.

RESULTS

A 40-year-old man presented with a recurrent orbital mass manifesting as progressive proptosis of the right eye of 4 years duration. The computed tomography scan and magnetic resonance imaging revealed an intraconal mass in the superior quadrant of the orbit. Histological analysis of the excision biopsy of the mass showed a highly cellular, locally infiltrating melanocytic neoplasm suggestive of an intermediate grade meningeal melanocytoma. Immunohistochemical staining for S-100 protein and HMB-45 monoclonal antibody confirmed the diagnosis.

CONCLUSIONS

Recurrent intermediate grade orbital melanocytomas are rarely encountered and have to be distinguished from other topographically similar primary melanotic tumors. They have to be managed more aggressively if intracranial extension is present due to its close relation to the visual pathways.

CPA Melanoma

OBJECTIVE

Melanoma rarely invades the cerebellopontine angle (CPA) and can evade accurate diagnosis, which may alter management decisions. Diagnosis may be facilitated via careful history, magnetic resonance imaging (MRI) findings, and cerebrospinal fluid (CSF) analysis.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

Thirteen internal auditory canal/CPA lesions in eight patients who presented with CPA syndrome and who had a pathological diagnosis consistent with malignant melanoma. There were four bilateral and four unilateral lesions. Six of eight patients had a history of melanoma. One was apparently primary CPA lesion, whereas all others were metastatic.

INTERVENTION(S)

T1- and T2-weighted precontrast and postcontrast gadolinium-enhanced MRI were obtained, including fat suppression and fluid-attenuated inversion recovery sequence images in two patients; lumbar puncture with CSF centrifugation and cytological analysis confirmed the diagnosis in two patients. Translabyrinthine craniotomy was performed for tumor extirpation in five patients.

MAIN OUTCOME MEASURE(S)

Symptoms at presentation, MRI findings, presence of malignant cells in CSF, tumor progression, intraoperative findings, response to treatment, time interval from initial diagnosis of melanoma elsewhere, and survival.

RESULTS

Seven of eight patients had history and/or MRI findings suggestive of malignancy in the internal auditory canal and/or CPA, and diagnosis was confirmed via CSF analysis in two patients. In one patient, diagnosis was made at surgery.

CONCLUSION

Internal auditory canal melanoma portends a grim prognosis, can occur up to 17 years after initial melanoma diagnosis/treatment, and can be detected with appropriate MRI sequences, especially enhanced fluid-attenuated inversion recovery images. In disseminated cases, diagnosis can be confirmed with lumbar puncture demonstrating malignant cells. Management includes tumor resection when melanoma seems to be solitary and malignant cells are not present in CSF. Intrathecal chemotherapy and radiation are recommended for dissemination, although the survival rate is still poor.

June 2002: 57-year-old male with leptomeningeal and liver tumors

The June 2002 COM. A male patient presented at the age of 57 years with a benign meningeal melanocytoma. Eight years later, the patient had a local recurrence of the tumor, cerebral metastases and liver metastases. This demonstrates that a correct diagnosis of melanocytic CNS tumors remains a challenge together with elucidating predictive markers for biological behavior. To the best of our knowledge, this is the first case of a melanocytoma associated with hepatic metastasis.

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.

Meningeal Melanocytoma Associated with Ipsilateral Nevus of Ota Presenting as Intracerebral Hemorrhage: Case Report

OBJECTIVE AND IMPORTANCE:

The authors report a rare case of meningeal melanocytoma presenting with unconsciousness, which was caused by an intracerebral hematoma and associated with a history of ipsilateral nevus of Ota.

CLINICAL PRESENTATION:

A 75-year-old woman developed nevus of Ota in the first and second divisions of the right trigeminal nerve territory, which had been treated with a skin graft 40 years earlier. She noticed right exophthalmos but left it untreated for 2 years and then became comatose owing to orbital and intracranial tumors, the latter manifesting with hemorrhage.

INTERVENTION:

She underwent craniotomy, during which the tumor was partially removed with intracerebral hematoma. Histopathologically, the tumor was diagnosed as meningeal melanocytoma. Western blot analysis demonstrated a retained protein expression of cell cycle inhibitor p16INK4A and a high level of antiapoptotic Bcl-2 in the resected tumor.

CONCLUSION:

The combination of nevus of Ota and meningeal melanocytoma has been reported in only four cases in the literature, including the current case. This is the first case coinciding with intracerebral hemorrhage, suggesting the necessity for careful follow-up with radiological images.

Meningeal melanocytoma of the posterior fossa: case report and literature review

BACKGROUND

Meningeal melanocytomas are rare primary melanotic tumors of the leptomeninges. According to our review of the literature, just 22 cases of meningeal melanocytoma (MM) of the posterior fossa have been previously reported. Some aspects related to diagnosis, radiological appearance, histopathologic features, and management are discussed in this paper.

CASE DESCRIPTION

We describe the case of a 42-year-old female presenting with severe headache, nausea, and vomiting. Computed tomography and magnetic resonance imaging demonstrated a posterior fossa lesion that was surgically treated. Histopathologic examination showed a highly cellular melanocytic neoplasm with numerous dark pigments in the cytoplasm. Immunoperoxidase staining S-100 protein and HMB 45 demonstrated immunoreactivity for both, confirming the diagnosis of MM.

CONCLUSIONS

In conclusion, MMs are rare histologically benign tumors that can be cured by complete surgical resection alone, which should be the goal of the treatment. These lesions, although rare, should be considered in the differential diagnosis of tumors of the posterior fossa.

Tumeur mélanocytaire méningée primitive de grade intermédiaire : confrontation radio-pathologique

A case of primary meningeal intermediate grade melanocytic neoplasm involving the right C2 nerve root is presented. MRI findings may suggest this rare entity, especially when an extra-axial lesion is located in the posterior fossa or cervical spinal canal and demonstrates shortening of both T1 and T2. Eventually, definitive diagnosis relies on histology which demonstrates spindle-shaped melanocytic cells that are Fontana stained and positive for HMB:45 antigen. Cellularity, pleomorphism, mitotic rate, proliferation index and invasiveness are useful criteria to distinguish among the spectrum of primary melanocytic tumors of the central nervous system ranging from melanocytoma to malignant melanoma.

Transition from meningeal melanocytoma to primary cerebral melanoma

✓ The authors describe the first case of an intracranial transition of a melanocytoma into a primary malignant melanoma within a short time. A 37-year-old woman presented with progressive brainstem syndrome due to a tumor, originally diagnosed and treated 12 years earlier, that extended from the petroclival area to the anterior craniocervical junction. The histological workup following subtotal tumor resection of the initial tumor had revealed the typical features of a fibrous melanocytic meningioma without increased proliferation. Ten years after the patient had completed treatment for the melanocytic meningioma, control neuroimaging demonstrated growth of the residual tumor with compression of the brainstem. Another neurosurgical intervention revealed a dark tumor of hard consistency. At this time immunohistochemical examinations demonstrated melanocytic features (expression of vimentin, S100 protein, and melan A) of the lesion with focally increased proliferation (5% of Ki-67—positive cells) but no higher mitotic activity. Clinical signs of deterioration along with imaging-confirmed tumor progression precipitated another operation within 7 months. A neuropathological examination revealed epithelial and anaplastic changes and indicated that the MIB-1 indices were greater than 25%. Pleomorphic changes and a focal high mitotic activity led to the diagnosis of a primary cerebral malignant melanoma. The patient's later clinical course consisted of a rapid diffuse meningeal spread of the lesion throughout the entire brain and spine. Despite whole-brain and stereotactic radiation therapy as well as chemotherapy, the patient died 4 months after the last neuropathological diagnosis. Although grossly resembling a meningioma, melanocytomas lack the former's histological and immunohistochemical features. The biological behavior of a melanocytoma is variable and recurrence may happen after subtotal resection, but intracranial transition into a malignant melanoma has not been observed previously.

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.

Meningeal melanocytoma of the brain and oculodermal melanocytosis (nevus of Ota): case report and literature review

BACKGROUND

Meningeal melanocytomas are rare benign pigmented tumors of meningeal melanocytes. Nevus of Ota is a melanocytic pigmentation of the sclera and the skin adjacent to the eye. We report a rare case of parietal convexity meningeal melanocytoma associated with ipsilateral mucocutaneous melanosis and review the literature.

METHODS

A 17-year-old man presented with headache and blindness. There was left scalp and facial mucocutaneous melanosis. During surgery, speckled hyperpigmentation was seen in all layers of the scalp, bone, dura, and even ependyma. Pathologic examination of the tumor and scalp consisted of light microscopy and immunohistochemistry. In a literature review, the demographics (age, sex), clinical characteristics (site of lesion, duration of symptoms), therapeutic options (surgical excision, radiotherapy), and prognosis (recurrence, death, death related to the disease, and follow-up) were analyzed. For statistical analysis we used the independent sample t-test and chi(2) tests.

RESULTS

Ninety-five cases (45 intracranial and 50 spinal) of meningeal melanocytoma have been reported. The median age of patients with intracranial lesions (40 years) was significantly lower than that of patients with spinal lesions (49 years) (p = 0.016). Of the 95 patients, 57.9% were female. In the nervous system, melanocytes are more common in the infratentorial and cervical areas, but more than half of the tumors have been located in the supratentorial region and the thoracic spine. In 46 months median follow-up, tumor recurrence rate and tumor related death rate were 26.3% and 10.5%, respectively. These were not statistically significant for different therapeutic modalities. There was a trend toward shorter survival for patients who underwent subtotal tumor resection without radiotherapy compared with other groups.

CONCLUSION

The prognostic criteria, differential diagnosis, and the embryological aspects of meningeal melanocytoma are discussed with a review of the related literature.

Two cases of spinal meningeal melanocytoma

Meningeal melanocytoma is a rare pigmented tumor originating from the melanocytes that generally occurs in the posterior fossa and the spinal cord. Although it is known as a relatively benign tumor, some recurrences have been reported. We report two cases of spinal meningeal melanocytoma with immunohistochemical and ultrastructural studies. In addition, we include a summary of published cases since the first case of Limas and Tio in 1972.

Intracranial meningeal melanocytoma

A 59-year-old man presented with a rare intracranial meningeal melanocytoma in the left cerebellopontine angle. The patient underwent partial surgical excision and radiosurgery for successful control of the tumor. Meningeal melanocytoma is an essentially benign melanotic tumor, derived from the melanocytes of the leptomeninges, and may occur anywhere in the cranial and spinal meninges. Preoperative differential diagnosis of intracranial meningeal melanocytoma from malignant melanoma is difficult based on magnetic resonance imaging. Ultrastructural findings are essential to establish the diagnosis. The prognosis of this tumor is not always favorable with occasional local recurrence. Total resection is the best treatment, but gamma knife radiosurgery is effective for the residual tumor following partial resection.

Suprasellar melanocytoma: a case of primary radiotherapy and review of the literature

Meningeal melanocytoma is a rare benign neoplasm of the central nervous system. Approximately 50% of the tumors are located intracranially with a preference for posterior fossa. We report a new case of intracranial suprasellar melanocytoma in a 57-year-old male patient treated with primary high-dose conformal radiotherapy to 50.4 Gy. Fourty-two months subsequent to treatment the tumor is well under control without neither deterioration of clinical symptoms nor progression of gross tumor volume on MR imaging. No late sequelae of treatment have been observed. A review of the literature is presented indicating that resection of melanocytoma is the treatment of first choice hampered by a relapse rate of approximately 30% depending on resection status. The role of adjuvant radiotherapy in patiens with complete resection of melanocytoma has not yet been defined. These patients carry a risk of relapse of approximately 15%, and adjuvant irradiation is currently not recommended. Primary high-dose radiotherapy has been shown to be effective in long-term control of the neoplasm in patients where no resection of the tumor could be accomplished. In case of incomplete resection of melanocytoma, data of the literature indicate that adjuvant radiotherapy may in fact increase long-term local control of the tumor. Requirements for optimal treatment results of radiotherapy are sufficiently high doses of, at least, 50 Gy for intracranial lesions and three-dimensional treatment planning guaranting precise targeting of the tumor volume with only a low-risk of late sequalae to the surrounding tissues.

Intracranial meningeal melanocytoma associated with ipsilateral nevus of Ota. Case report

In this report, the authors review the case of a man with a neurocutaneous syndrome. He presented with an intracerebral melanocytoma associated with a blue nevus of the scalp; its location and its appearance during childhood supported the diagnosis of a nevus of Ota. Meningeal melanocytomas are increasingly being diagnosed, but remain rare. Primary meningeal malignant melanoma is the first differential diagnosis to eliminate. Despite their common embryonic origin. the association of a melanocytoma with a nevus of Ota is rare. A nevus of Ota exhibits the same melanocytic proliferation and affects the trigeminal nerve territory. An ocular effect is not always observed. In contrast to an ocular lesion, a nevus of Ota rarely transforms into a malignant melanoma. It is found only among caucasians. During 4 years of follow-up review after surgery, the patient remained asymptomatic. Other than antiepileptic therapy, he received no complementary treatment and cerebral imaging revealed no evidence of recurrence.

Therapeutic options for meningeal melanocytoma. Case report

Meningeal melanocytomas are uncommon lesions. They are generally considered to be benign tumors that derive from leptomeningeal melanocytes. A rare case of a metastatic spinal meningeal melanocytoma is presented. All relevant cases reported in literature since 1972, when the term "meningeal melanocytoma" was first used, were reviewed. Rates of tumor recurrence from 1 to 5 years were calculated for this rare lesion, based on published data and on additional information obtained from personal contact with most of the authors. Recurrency rates of 47 patients suitable for evaluation were correlated with the different therapeutic approaches. Complete tumor resection alone and incomplete resection alone followed by irradiation appeared to be superior to incomplete resection alone in terms of disease-free survival. Statistical significance was achieved for complete tumor resection at follow up between I and 4 years (range p = 0.010-0.050) and for incomplete resection combined with radiotherapy after 2 years (p = 0.034). Complete tumor resection should be considered the best therapeutic option, followed by incomplete resection combined with postoperative radiotherapy.

Meningeal melanocytoma of the planum sphenoidale. Case report and review of the literature

Meningeal melanocytoma is a rare benign primary melanotic tumor of the meninges, most commonly found in the spinal canal and the posterior fossa. The authors report the 19th published case of a supratentorial meningeal melanocytoma and the first reported case in which the tumor arose from the planum sphenoidale. The patient's presenting symptoms were characteristic of a large bifrontal lesion and included headaches, personality change, lethargy, and urinary and fecal incontinence. Computerized tomography and magnetic resonance imaging studies revealed an extraaxial lesion arising from the planum sphenoidale. The patient underwent successful gross total removal of the tumor without neurological sequelae. Based on the findings shown in this case report, meningeal melanocytoma should be included in the differential diagnosis of extraaxial lesions arising from the area of the planum sphenoidale.

Radiosurgery of meningeal melanocytoma

The authors present a case of meningeal melanocytoma arising from Meckel's cave. A coal-black, vascular tumor was partially removed by surgery. Histopathologically, the tumor lacked anaplastic features. Immunohistochemical studies confirmed that the tumor was of neuroectodermal origin and had low proliferating activity. The patient underwent gamma knife radiosurgery for the residual tumor, in which 25 Gy of radiation was delivered to the tumor margin. Three years after irradiation, the tumor showed marked shrinkage without complication.