Primary solitary intracranial melanoma: case report and review of the literature

Primary cerebral melanoma: An exceptional localization in a case report

Cerebral melanoma is often related to a secondary location of a cutaneous or mucosal melanoma. However, primary cerebral melanoma is a very rare clinical situation, representing less than 1% of all melanomas and 0.07% of all cerebral tumors. The diagnosis of a primary cerebral melanoma therefore requires rigorous clinical and paraclinical investigations. We report a case of primary cerebral melanoma treated in our onco-radiotherapy department.

Unusual case of intraosseous primary intracranial malignant melanoma

Primary intracranial malignant melanoma (PIMM) represents 0.07% of central nervous system tumours; clinical behaviour and prognosis are not well documented. Preoperative diagnosis of PIMM is complex and it could be easily misdiagnosed, especially with malignant meningioma.We are reporting a case of a man with a history of rapidly arising motor slowing associated with urinary incontinence, presenting with mild convergent strabismus caused by paralysis in abduction in the right eye. A brain CT showed a lesion compatible with malignant spheno-orbital meningioma, and the patient underwent gross total resection. Intraoperatively, the blackish lesion infiltrated and eroded the bone; it was placed externally on the dura mater with a mild reaction and without attachment. Histological examination confirmed PIMM.Intraosseous localisation of PIMM has been observed in the basic bone structure of the oral cavity. We report the first intraosseous spheno-orbital PIMM case and present an embryological theory about how this unusual tumour can develop.

Atypical primary malignant melanoma originating in the spinal canal: A case report and literature review

Central nervous system (CNS) malignant melanomas are rare tumors of the CNS that are thought to arise from aberrant changes in melanocytes of the neural crest or melanocytic elements of the pia mater during early embryonic development. As a rare type of CNS malignant melanoma, only a few cases of primary malignant melanoma in the spinal canal have been reported thus far. The majority of these studies have reported on the diagnosis, radiographic features and gross total resection of primary spinal canal malignant melanoma; however, the prognosis and ideal treatment of patients with residual tumors remain elusive. The current study presented the rare case of a patient with primary malignant melanoma originating from the thoracic spinal canal, without any history of irradiation exposure and with an incompletely resected tumor. Disease-free survival of >2.5 years was observed in this patient who was treated with concurrent chemoradiotherapy followed by adjuvant chemotherapy with temozolomide and bevacizumab.

Longest survival with primary intracranial malignant melanoma: A case report and literature review

BACKGROUND

Primary intracranial malignant melanoma (PIMM) is rare, and its prognosis is very poor. It is not clear what systematic treatment strategy can achieve long-term survival. This case study attempted to identify the optimal strategy for long-term survival outcomes by reviewing the PIMM patient with the longest survival following comprehensive treatment and by reviewing the related literature.

CASE SUMMARY

The patient is a 47-year-old Chinese man who suffered from dizziness and gait disturbance. He underwent surgery for right cerebellum melanoma and was subsequently diagnosed by pathology in June 2000. After the surgery, the patient received three cycles of chemotherapy but relapsed locally within 4 mo. Following the second surgery for total tumor resection, the patient received an injection of Newcastle disease virus-modified tumor vaccine, interferon, and β-elemene treatment. The patient was tumor-free with a normal life for 21 years before the onset of the recurrence of melanoma without any symptoms in July 2021. A third gross-total resection with adjuvant radiotherapy and temozolomide therapy was performed. Brain magnetic resonance imaging showed no residual tumor or recurrence 3 mo after the 3^rd operation, and the patient recovered well without neurological dysfunction until the last follow-up in June 2022, which was 22 years following the initial treatment.

CONCLUSION

It is important for patients with PIMM to receive comprehensive treatment to enable the application of the most appropriate treatment strategies. Long-term survival is not impossible in patients with these malignancies.

Primary Intracranial Brainstem Malignant Melanoma: A Technical Case Report

BACKGROUND AND IMPORTANCE

Primary intracranial malignant melanomas (PIMMs) are quite rare, comprising 1% of melanomas and 0.07% of intracranial tumors. PIMMs have been reported in a variety of intracranial locations, but there has only been 1 reported instance of PIMM occurring in the brainstem. In this study, we describe the second reported case of primary pontine malignant melanoma and its treatment.

CLINICAL PRESENTATION

A 40-year-old man presented with right hemiparesis, diplopia, and dysarthria. MRI demonstrated a hemorrhagic, expansile, and heterogeneously enhancing lesion in the left pons with edema extending to the left thalamus and posterior limb of the internal capsule. Surgical resection was performed through a transpetrosal approach. Pathology resulted as malignant melanoma immunopositive for BRAF V600E mutation. Complete oncological workup revealed no other lesions; thus, he was diagnosed with PIMM of the brainstem.

CONCLUSION

We report a rare case of primary pontine malignant melanoma in which microsurgical resection resulted in dramatic clinical improvement despite the challenging location. This is only the second reported case of brainstem PIMM. More patients with longer-term follow-up will be necessary to determine the best treatment approach.

Primary intracranial malignant melanomas in solitary type: a tertiary center experience

PURPOSE

Solitary type primary intracranial malignant melanoma (PIMM) is extremely rare but fatal. The optimal treatment algorithm according to clinical relevance of symptoms and outcomes is unclear. This series emphasized the prognostic factors of solitary PIMM and established the treatment algorithm for this rare disease.

METHODS

Patients with solitary PIMMs were pathologically verified and treated with neurosurgical tumor resection. All solitary PIMMs recruited at our institute received multidisciplinary team care. We analyzed the clinical findings and prognostic factors.

RESULTS

The study cohort included 10 patients. PIMMs in solitary type impacted middle-aged populations with male predominance in Taiwan. Most patients (80%) presented a single tumor initially. Six patients had progressed to multiplicity after the initial treatment. Rates of tumor bleeding and leptomeningeal metastasis seeding (LS) are high in solitary PIMMs. Patients who had gross-total resection (GTR) had better survival than those who had incomplete resection, with median overall survival (OS) rates of 170.4 months vs. 5.23 months (p = 0.004). Multiplicity, eloquent area involvement, initial tumor bleeding, LS, hydrocephalus, and Karnofsky Performance Score < 80 at diagnosis were associated with negative outcomes in progression-free survival and OS. Adjuvant radiotherapy for patients who had LS and for those who cannot undergo grossly total tumor removal resulted in a good outcome.

CONCLUSIONS

GTR demonstrated better outcomes for solitary PIMM. For recurrent tumors, aggressively repeated surgical resection remained beneficial for selected cases. Adjuvant radiotherapy was a treatment option for LS following operation. We proposed a possible treatment algorithm for solitary PIMM.

Sudden Death from Primary Cerebral Melanoma: Clinical Signs and Pathological Observations

Primary cerebral tumors rarely provoke sudden death. The incidence is often underestimated with reported frequencies in the range of 0.02 to 2.1% in medicolegal autopsy series. Furthermore, primary cerebral melanoma is an uncommon neoplasm. It represents approximately 1% of all melanoma cases and 0.07% of all brain tumors. This neoplasm is very aggressive, and its annual incidence is about 1 in 10 million people. In the present study, a 20-year-old male was admitted to hospital with vomiting, headache, paresthesia and aggressive behavior. A computed tomography (CT) scan of the head was performed showing a hyperdense nodule in the right parietal lobe with inflammation of the Silvian fissure. A complete autopsy was performed 48 h after death. A blackish material was displayed on the skull base, and posterior fossa. Microscopic examination diagnosed primary brain melanoma. A systematic review of the literature was also performed where no previous analogous cases were found. The forensic pathologist rarely encounters primary cerebral melanoma, and for these reasons, it seemed appropriate to describe this case as presenting aspecific clinical symptoms and leading to sudden unexpected death. Histopathological observations are reported and discussed to explain this surprising sudden death caused by a primary cerebral melanoma.

Primary intracranial malignant melanoma: proposed treatment protocol and overall survival in a single-institution series of 15 cases combined with 100 cases from the literature

OBJECTIVE

The overall survival and pertinent adverse factors for primary intracranial malignant melanoma (PIMM) have not been previously determined. This aim of this study was to determine the rates of progression-free survival (PFS) and overall survival (OS) and identify the adverse factors for PIMM.

METHODS

This study included 15 cases from the authors' own series and 100 cases with detailed clinical data that were obtained from the literature from 1914 to 2018 using the Ovid Medline, EMBASE, PubMed, Cochrane, and EBSCO databases. Patient demographics, treatment (surgery, chemotherapy, and radiotherapy [RT]), PFS, and OS were reviewed. Data from prior publications were processed and used according to PRISMA guidelines.

RESULTS

Diffuse lesions were identified in 24 (20.9%) patients, who had a younger age (p < 0.001). The mean follow-up time was 16.6 months, and 76 (66.1%) deaths occurred. The 6-month, 1-year, 3-year, and 5-year OS rates of the whole cohort were 62.8%, 49.9%, 28.9%, and 17.2%, respectively, with an estimated median survival time (EMST) of 12.0 months. The multivariate analysis revealed that gross-total resection (GTR) (HR 0.299, 95% CI 0.180-0.497, p < 0.001), radiotherapy (HR 0.577, 95% CI 0.359-0.929, p = 0.024), and chemotherapy (HR 0.420, 95% CI 0.240-0.735, p = 0.002) predicted a better OS. The EMST was 5.0 months in patients with diffuse-type PIMM and 13.0 months in patients with the solitary type. Patients receiving GTR with adjuvant RT and/or chemotherapy (GTR + [RT and/or chemo]) had significantly higher 1-year and 5-year OS rates (73.0% and 40.1%, respectively) and a longer EMST (53 months) than patients who underwent GTR alone (20.5 months) or RT and/or chemotherapy without GTR (13.0 months).

CONCLUSIONS

Optimal outcomes could be achieved by radical resection plus postoperative radiotherapy and/or chemotherapy. Patients with diffuse PIMM have a more severe clinical spectrum and poorer survival than patients with solitary PIMM. Immunotherapy and targeted therapy show promise as treatment options for PIMM based on results in patients with brain metastases from extracranial melanoma.

Primary Malignant Melanoma of the Brain: A Population-Based Study

BACKGROUND

Primary melanocytic neoplasms of the central nervous system (CNS) are rare and account for 1% of all melanomas. This study used the Surveillance, Epidemiology, and End Results (SEER) database to evaluate the epidemiology of primary CNS melanoma and further characterize their treatment.

METHODS

Data from the National Cancer Institute SEER program, collected from 1973-2015, were retrospectively analyzed. A total of 86 records of malignant melanoma cases with CNS as the primary site were identified, and 54 patients were studied based on the inclusion criteria. Demographic, tumor, and treatment regimen effectiveness were studied.

RESULTS

A total of 54 patients were included in this study. Tumors were distributed evenly in size and localized primarily to the cerebral meninges and spinal cord. A total of 13% of patients underwent biopsy, 40.7% gross total resection (GTR), 7.4% subtotal resection (STR), 46.3% radiation therapy (RT), and 27.3% chemotherapy (CT) in a variety of treatment combinations. GTR alone and STR + RT resulted in increased disease-specific survival compared to biopsy alone, but no survival benefit was found with biopsy with RT and/or CT as well as STR alone.

CONCLUSIONS

To our knowledge, this is the largest single database study completed for primary malignant melanoma of the CNS. The study identified the need for tumor resection for the proper treatment of these lesions, particularly GTR. GTR could be paired with adjuvant RT or RT + CT providing survival benefit as well. In cases when GTR is unable to be completed, STR + RT provides significant improvement in survival compared to biopsy alone.

Aggressive Primary Pediatric Intracranial Malignant Melanoma: Sphinx of the Tissue Diagnosis

It is often intriguing to suspect and confirm the diagnosis of primary malignant melanoma (PMM) in the brain without any evidence of neurocutaneous melanosis. We report a 16-year-old male patient with malignant melanoma which intraoperatively was small sized, soft, fleshy, hemorrhagic in appearance resembling hematoma. Interestingly, the histopathology showed prominent papillary architecture with a differential diagnosis of papillary meningioma and ependymoma and perplexed the tissue diagnosis. This case is discussed in light of very uncommon occurrence of intracranial PMM in pediatric age group, enigmatic histological features, and aggressive nature of lesion with rapid progression despite complete excision following radiation therapy.

Primary Solitary Intracranial Malignant Melanoma: A Systematic Review of Literature

INTRODUCTION

Primary solitary intracranial malignant melanoma (PIMM) is extremely rare. In 1992, an extensive review of 81 patients with PIMM was undertaken. Imaging studies, microsurgery, and adjuvant therapy have developed considerably over the last 25 years, and targeted therapy recently has been proven successful for metastatic melanoma. These factors could influence current and future clinical PIMM results.

METHODS

We undertook a literature search of PIMM patients since 1992.

RESULTS

We reviewed 49 cases of PIMM. The mean age was 45.8 years. No significant sex difference was found. Intracranial hypertension and focal neurologic deficits were commonly observed around 70% and 40%, respectively. There were no significant differences of survival period according to tumor sites. Surgeries were performed in 42 of 49 patients with PIMM reviewed (92%). The mean survival of the gross total removal group was significantly longer than that of surgical results (>22 months vs. 12 months (interquartile range: 5-22 months; P = 0.026). For adjuvant therapy, 9 patients underwent chemotherapy and 18 patients underwent radiotherapy postoperatively There was no significant difference in survival period between with and without adjuvant therapies. Leptomeningeal enhancement diagnosed in the initial MRI, was the worst prognostic factor.

CONCLUSIONS

Gross total removal of the PIMM was the most promising treatment. Currently adjuvant therapy has not been associated with the survival period. To improve clinical outcome, immunotherapy and targeted therapies are likely to become more important.

A Unique Case of Primary Intracranial Melanoma

Primary intracranial melanoma is an uncommon entity and only case reports have been published in the literature. We report a case of an elderly male who was operated with a preliminary diagnosis of meningioma, but it proved to be a histological surprise as it came out to be melanoma with no primary anywhere in the body.

Primary cerebral malignant melanoma: A case report with literature review

Primary intracranial melanomas are uncommon and constitute approximately 1% of all melanoma cases and 0.07% of all brain tumors. In nature, these primary melanomas are very aggressive and can spread to other organs.We report an uncommon case of primary cerebral malignant melanoma-a challenging diagnosis guided by clinical presentations, radiological features, and surgical biopsy results, aiming to emphasize the importance of considering primary melanoma when making differential diagnoses of intracranial lesions.We present a rare case of a primary cerebral melanoma in the left temporal lobe. The mass appeared iso-hypodense on brain computed tomography (CT), short signal on T1-weighted magnetic resonance images (T1WI) and long signal on T2WI. It was not easy to make an accurate diagnosis before surgery. We showed the patient's disease course and reviewed related literatures, for readers' reference. Written informed consent was obtained from the patient for publication of this case report and any accompanying images. Because of this, there is no need to conduct special ethic review and the ethical approval is not necessary.After surgery, the pathological examination confirmed the diagnosis of melanoma. The patient was discharged without any complications and went on to receive adjuvant radiochemotherapy.It is difficult to diagnose primary cerebral melanoma in the absence of any cutaneous melanosis. A high index of clinical suspicion along with good pathology reporting is the key in diagnosing these extremely rare tumors.

Primary Intracranial Malignant Melanoma with Extracranial Metastasis

We report a case of primary intracranial malignant melanoma (PIMM) with extracranial metastases. The patient was an 82-year-old woman diagnosed with PIMM under the left cerebellar tentorium. We performed a tumor resection followed by gamma knife surgery. An magnetic resonance imaging at 11 months after surgery showed a local intracranial recurrence. At 12 months, vertebral metastasis was suspected, and 2-[fluorine-18]-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (FDG-PET/CT) showed multiple extracranial metastases. She died at 13 months after surgery. Although extracranial metastases of PIMM are extremely rare, we should carefully follow up extracranial metastases together with intracranial ones, especially by FDG-PET/CT, even at an early asymptomatic stage.

Sudden Death and Primary Leptomeningeal Melanocytosis: A Case Report With an Autopsy Diagnosis

Meningeal melanocytoma is a rare benign pigmented tumor. It develops from melanocytes normally present in the meninges of the posterior fossa and medulla. It is an extra-axial tumor that manifests because of compression of adjacent structures. Although classified as a benign tumor, it can cause sudden death by several mechanisms. We report a rare case of meningeal melanocytoma and discuss the mechanism of death. A 21-year-old man with a previous history of recurrent lipothymia was admitted to the emergency department because of generalized seizures. Death occurred despite resuscitation. A medico-legal autopsy was performed. External examination of the body showed nonspecific asphyxia signs without any violence evidence. Necropsy noticed a brain edema with a dark color of the meninges especially in the frontal part. Histological examination concluded to diffuse meningeal melanocytoma with cerebral edema.

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.

Primary Intracranial Melanoma with Early Leptomeningeal Spread: A Case Report and Treatment Options Available

Primary CNS melanomas are rare and they constitute about 1% of all cases of melanomas and 0.07% of all brain tumors. These tumors are aggressive in nature and may metastasise to other organs. Till date less than 25 cases have been reported in the literature. The primary treatment for local intraparenchymal tumours is complete resection and/or radiotherapy and it is associated with good survival. However once there is disease spread to leptomeninges the overall median survival is around 10 weeks. In this case report we describe a primary intracranial melanoma without any dural attachment in 16-year-old boy who had radical excision of the tumor followed by radiotherapy who eventually had rapidly developed leptomeningeal disease and review the literature with a focus on the clinic pathological, radiological, and treatment options.

Primary melanoma of the cochlea with cerebellopontine extension and leptomeningeal spread

BACKGROUND

Less than 1 per cent of tumours occurring in the region encompassing the internal auditory canal and the cerebellopontine angle are malignant. Primary central nervous system melanomas arising from this region are exceptionally rare and are often initially misdiagnosed as acoustic neuromas.

METHODS

We present a 71-year-old man with acute vestibular disturbance and unilateral hearing loss. Magnetic resonance imaging demonstrated a mass, thought to be a cochlear nerve schwannoma, involving the cochlea and the internal auditory canal. At surgery, a pigmented mass adherent to the facial nerve was visualised, and the observed histopathology was consistent with a malignant melanoma. No extracranial site for the primary tumour was found, suggestive of a primary central nervous system melanoma.

RESULTS

Despite surgical resection and adjuvant radiotherapy, the patient re-presented with extensive leptomeningeal disease 16 months later.

CONCLUSION

Malignant tumours in the internal auditory canal and cerebellopontine angle region are rare. Early diagnosis and management are aided by recognition of characteristic factors such as a history of prior malignancy, atypical magnetic resonance imaging findings and accelerated audiovestibular symptoms. Despite the presented patient's outcome, total surgical resection with post-operative radiotherapy remains the recommended treatment.

A rare case of primary malignant melanoma of clivus with extensive skeletal metastasis demonstrated on 18F-FDG PET/CT

Malignant melanoma of the clivus is a rare entity, for which there is little evidence-based literature for guiding clinicians to understand the importance of disease staging via noninvasive imaging strategy. This report highlights the case of a 55-year-old lady with histopathologically confirmed melanocytic melanoma of the clivus-postoperative status, with multiple skeletal metastasis, demonstrated on 2-deoxy-2-[18F] fluoro-D-glucose positron emission tomography/computed tomography (18F-FDG PET/CT scan). The experience gained with this patient demonstrates the feasibility and usefulness of this noninvasive application in accurate staging and hence, correct decision making regarding further treatment.

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 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.

Intra-axial brainstem malignant melanoma mimicking cavernous angioma--case report

A 41-year-old female presented with repeated pontine hemorrhage. Magnetic resonance imaging showed the pontine hemorrhage as a heterogeneously enhanced mass mimicking cavernous angioma. The mass lesion was removed via a midline suboccipital approach. Histological examination showed malignant melanoma cells. No cutaneous lesion was found and positron emission tomography found no abnormalities. Our presumptive diagnosis was primary intra-axial brainstem malignant melanoma. The possibility of malignant melanoma should be considered in patients with intra-axial brainstem lesion associated with repeated hemorrhages.

Multiple intracranial melanoma metastases: case report and review of the literature

Although intracerebral metastases of malignant melanoma are common, those located in the sellar region and within the pontocerebellar area are extremely rare. Furthermore, to our knowledge, there is no report about melanoma metastasis to the epiphysis published so far. We report here a 46-year-old patient who had metastatic lesions in the sellar region, cerebellopontine area and epiphysial gland, preceded by a primary melanoma at her left shoulder. The diagnosis of sellar metastasis was confirmed histopathologically following a stereotactic biopsy. The patient received whole-brain irradiation therapy combined with chemotherapy. After 10 months, she died from a severe hemorrhage in the cerebellopontine angle. Autopsy findings confirmed melanoma metastases both in the cerebellopontine angle and additionally in the epiphysial gland. To our knowledge, this is the first case of multiple intracranial melanoma metastases including the suprasellar region, the pontocerebellar and epiphysial area.

Bilateral Cerebellopontine Angle Metastatic Melanoma: A Case Report

Although melanoma accounts for approximately 1% of all malignancies, melanoma metastases to the cerebellopontine angles (CPAs) are exceedingly rare. Here we describe a patient with melanoma metastases to the internal auditory canals and CPAs who presented with a remote history of cutaneous melanoma. This patient had a rapidly progressive hearing loss, vestibulopathy, and facial nerve dysfunction. Magnetic resonance imaging demonstrated bilateral, enhancing CPA lesions but was otherwise nonspecific. The diagnosis required a careful history, unilateral surgical resection for tissue acquisition, and histopathologic confirmation. A search for primary cutaneous melanoma at the time of presentation was negative. However, the history of cutaneous melanoma 8 years earlier distinguishes this patient's metastatic disease from solitary primary intracranial melanoma, an equally rare disease. Treatment consists of surgical excision, radiation, chemotherapy, and immunotherapy. The prognosis for patients with melanoma metastases is generally poor, but isolated reports of long-term survival have been described. Metastatic disease to the CPAs must be included in the differential diagnosis for any patient presenting with rapid-onset VIIth or VIIIth cranial nerve symptoms.

Central nervous system as exclusive site of disease in patients with melanoma: treatment and clinical outcome of two cases

The central nervous system (CNS) is a favourite site of metastasis in advanced melanoma and, despite the improvement obtained in the control of brain metastasis, most patients die as a result of extracranial progression of the disease. CNS primary malignant melanoma is a rare entity and the diagnosis is generally made after the exclusion of a primary cutaneous or mucosal/retinal malignant melanoma, as differential histological diagnosis between primary and metastatic origins is often difficult. From a review of the literature, patients with primary brain melanoma or exclusive (and limited) brain metastasis in the absence of extracranial melanoma present a relatively good prognosis if adequately treated with aggressive locoregional treatments (neurosurgery and/or radiotherapy) and, later, with drugs able to cross the blood-brain barrier (i.e. fotemustine). In this letter, we describe the history, treatment and favourable clinical outcome of two patients with melanoma and CNS as the exclusive site of disease.

Primary Intracranial Melanocytic Tumor Simulating Pituitary Macroadenoma: Case Report and Review of the Literature

OBJECTIVE AND IMPORTANCE:

Primary intracranial melanocytic tumors are rare lesions, sellar ones being even more exceptional. So far, six melanomas and two melanocytomas have been described in an intrasellar and/or suprasellar location.

CLINICAL PRESENTATION:

We report on the case of a 25-year-old Caucasian woman presenting with a 4-year history of amenorrhea and an intrasellar mass with suprasellar extension suggestive of a pituitary macroadenoma.

INTERVENTION:

A gross subtotal resection of a hemorrhagic tumor was performed. Histological examination revealed melanin-laden pleomorphic tumor cells that tested positive for HMB-45 and S-100 and negative for cytokeratins, thus demonstrating that the tumor was a melanocytic neoplasm. An extensive workup failed to find evidence of any other primary site. The patient received no further treatment and is alive and well after 24 months of follow-up.

CONCLUSION:

Primary sellar melanocytic neoplasms are extremely rare lesions and present with few differential diagnoses. Deciding whether the tumor is best classified as a melanocytoma or a melanoma may prove difficult. Wide histological variations in both melanocytomas and melanomas render careful consideration of the clinical, radiological, and gross features essential in distinguishing one from the other.

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.

Primary Malignant Cerebellopontine Angle Melanoma Presenting as a Presumed Meningioma: Case Report and Review of the Literature

Primary intracranial melanomas are rare, especially in the primary cerebellopontine angle. We describe a patient with a presumed jugular foramen meningioma that was found to be of melanotic origin at surgery. We followed this 26-year-old woman with mild ataxia with serial imaging for 18 months after the initial discovery of a cerebellopontine angle extra-axial mass. She developed worsening symptoms of ataxia, dysphagia, and right-sided hearing loss. Magnetic resonance imaging showed an interval increase in size of the mass. The lesion was thought to be a meningioma with a dural tail that extended into the jugular foramen and hypoglossal canal. She underwent preoperative angiography and attempted tumor embolization, followed by resection via a transcochlear infratemporal approach. At surgery the lesion was found to be heavily pigmented. Pathological analysis was consistent with a low-grade melanoma. No primary extracranial site was identified. One year after surgery the patient remains free of systemic disease or recurrence.

Dural lesions mimicking meningiomas

Recently, a number of neoplastic and nonneoplastic entities have been reported that radiographically and clinically mimic meningiomas. Because these lesions occur infrequently and may resemble a meningioma during intraoperative analysis, they may not be considered in the differential diagnosis. This review (and case illustrations) considers some of the newly recognized and notable lesions that can mimic meningiomas, including solitary fibrous tumors, gliosarcomas, leiomyosarcomas, hemangiopericytomas, melanocytomas, Hodgkin's disease, plasmacytomas, inflammatory pseudotumors, neurosarcoidosis, plasma cell granulomas, Rosai-Dorfman disease, Castleman's disease, xanthomas, rheumatoid nodules, and tuberculomas. Awareness that these lesions involve the dura may facilitate intraoperative recognition and, in some cases, preclude unnecessary additional surgery.

Primary melanocytic neoplasms of the central nervous systems

Primary melanocytic neoplasms of the central nervous system (CNS) consist of a spectrum ranging from well-differentiated melanocytoma to its overtly malignant counterpart, melanoma. Diagnostically difficult intermediate lesions lie between these extremes. Clinicopathologic features of 33 cases were studied to define histologic appearances, diagnostic criteria, and the clinical behavior of lesions along this spectrum. Seventeen cases were well-differentiated, solitary leptomeningeal tumors classified as melanocytomas. They contained variably pigmented melanocytic cells arranged in tight nests, sheets, or fascicles. Mitotic rates ranged from zero to one per 10 high-power fields (HPFs), with most having zero per 10 HPFs. All tumors were immunoreactive for HMB-45 and S-100 protein and negative for epithelial membrane antigen. MIB-1 staining was low (<1-2%). Nuclei were regular, often with small, eosinophilic nucleoli. These lesions arose predominantly in the spinal canal (65%) in patients ranging in age from 17 to 73 years. None recurred after surgical resection. In contrast to these benign lesions, there were 13 cases with histologic and cytologic features consistent with those of malignant melanoma. These cases contained larger, cytologically atypical, pigmented tumor cells growing in loose nests or sheets, often with CNS invasion or necrosis. Some contained bizarre, pleomorphic nuclei; others were densely cellular and mitotically active, but less pleomorphic. Mitotic rates (mean, 5.7 per 10 HPFs) and MIB-1 labeling indices (mean, 8.1%) were higher than those of melanocytomas. Melanomas occurred at spinal (38%), posterior fossa (38%), and supratentorial (23%) levels in patients ranging in age from 15 to 71 years. After resection, 8 of 13 lesions recurred, with four being fatal (mean survival, 14 months). Of five totally resected melanomas, four did not recur (mean follow-up, 26 months). Three intermediate-grade melanocytic tumors could not be classified as melanocytoma or melanoma. All showed sheetlike growth patterns, microscopic CNS invasion, and occasional mitoses. MIB-1 staining ranged from 1% to 4%. One tumor recurred after 17 months; one patient was lost to follow-up after 5 months; and the third died after surgery. Although melanocytic tumors represent a spectrum of lesions, certain histopathologic features are helpful in predicting biologic behavior.

Treatment of melanoma metastases in the brain

Melanoma is prone to spread to the brain and is the third most common source of intracranial metastasis. Patients usually present with signs and symptoms of increased intracranial pressure, a new focal neurologic deficit, or seizures. Contrasted magnetic resonance imaging (MRI) is the single most valuable imaging modality. Surgical therapy is the appropriate choice for single lesions that are accessible, especially if they are causing significant mass effect or are located in the posterior fossa. Patients with several intracranial metastases who undergo resection of all lesions may have a similar prognosis to those with single resected lesion. Stereotactic radiosurgery appears to provide good local control of small lesions. External beam radiotherapy may provide some benefit to patients, and is often used in conjunction with surgery or stereotactic radiosurgery. To date, chemotherapy has been limited because of chemo-resistance and drug delivery issues. Future directions for treatment may include local sustained delivery of either chemotherapy or immunoregulatory molecules.