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

Clinicopathological features, current status, and progress of primary central nervous system melanoma diagnosis and treatment

Primary central nervous system (CNS) melanoma is an extremely rare condition, with an incidence rate of 0.01 per 100,000 individuals per year. Despite its rarity, the etiology and pathogenesis of this disease are not yet fully understood. Primary CNS melanoma exhibits highly aggressive biological behavior and presents clinically in a distinct manner from other types of melanomas. It can develop at any age, predominantly affecting the meninges as the primary site, with clinical symptoms varying depending on the neoplasm's location. Due to the lack of specificity in its presentation and the challenging nature of imaging diagnosis, distinguishing primary CNS melanoma from other CNS diseases. The combination of challenges in early detection, heightened tumor aggressiveness, and the obscured location of its origin contribute to an unfavorable prognostic outcome. Furthermore, there has been currently no consensus on a standardized treatment approach for primary CNS melanoma. Despite recent advancements in targeted therapy and immunotherapy for CNS melanoma, patients with primary CNS melanoma have limited treatment options due to their inadequate response to these therapies. Here, we provided a comprehensive summary of the epidemiology, clinical features, molecular pathological manifestations, and available diagnostic and therapeutic approaches of primary CNS melanoma. Additionally, we proposed potential therapeutic strategies for it.

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.

A Rare Case of Primary Intracerebral Malignant Melanoma

Malignant melanomas occurring in the central nervous system are mostly metastatic. Primary intracranial malignant melanomas are a rare entity, accounting for 0.07% of all brain tumors. In the central nervous system, melanocytes originate from the neural crest cells that are found in the leptomeninges. Only a few cases of malignant melanoma primarily arising from the brain have been reported in the literature to date. We report a rare case of primary intracerebral malignant melanoma in a 39-year-old female. Through this case report, our aim is to highlight the role of imaging in the early diagnosis and management of malignant melanoma.

Pediatric Primary Intracranial Malignant Melanoma: Case Report and Literature Review

INTRODUCTION

Primary intracranial malignant melanoma (PIMM) is an extremely rare primary brain tumor with most cases diagnosed in adults. To date, there are only a few cases reported in the pediatric population. Owing to its infrequency, there are no established guidelines to treat this aggressive neoplasm. Recent insights suggest that PIMM are molecularly different between adults and children, whereby NRAS mutations drive tumor growth in the latter group. We present a unique case of PIMM in a pediatric patient and discuss the case in corroboration with current literature.

CASE PRESENTATION

A previously well 15-year-old male presented with progressive symptoms of raised intracranial pressure. Neuroimaging reported a large solid-cystic lesion with significant mass effect. He underwent gross total resection of the lesion that was reported to be a PIMM with pathogenic single nucleotide variant NRAS p.Gln61Lys. Further workup for cutaneous, uveal, and visceral malignant melanoma was negative. A trial of whole-brain radiotherapy followed by dual immune checkpoint inhibitors was commenced. Despite concerted efforts, the patient had aggressive tumor progression and eventually demised from his disease.

CONCLUSION

We therein report a case of pediatric PIMM, in the context of the patient's clinical, radiological, histopathological, and molecular findings. This case highlights the therapeutic difficulties faced in disease management and contributes to the very limited pool of medical literature for this devastating primary brain tumor.

An atypical primary malignant melanoma arising from the cervical nerve root: A case report and review of literture

BACKGROUND

Primary melanomas affecting the central nervous system are very rare, and melanomas originating in the spinal canal or origin of the spinal nerve root are even rarer. As a consequence, not much is known about this.

CASE SUMMARY

Here we report a case of primary malignant melanoma originating in the cervical spinal cord nerve root. A 64-year-old woman presented with symptoms of numbness in the right side of the neck, pain, and hypoesthesia in the right upper limb which persisted for 1 year. Neurological examination showed that the superficial sensation in the right upper limb had decreased with muscle strength of grade 4. Magnetic resonance imaging examination revealed a mass (approximately 2.5 cm × 1.4 cm × 1 cm) in the right side of the spinal canal in the C-2 plane. Based on findings obtained during operation, perioperative examination, pathological diagnosis, and the diagnostic criteria of primary central melanoma proposed by Hayward, the mass was confirmed to be a melanoma of intraspinal nerve root origin.

CONCLUSION

This is the first case of primary malignant melanoma originating from cervical spinal cord nerve roots and spread along the inside and outside of the spinal canal. The clinical relevance of this case is discussed to provide new insights into the differential diagnosis of intraspinal tumours. Further studies are needed to better understand the mechanisms driving the growth pattern and development of this type of tumour.

Primary Intramedullary Spinal Melanoma: A Rare Disease of the Spinal Cord

Primary malignant melanoma of the intramedullary region of the spinal cord has rarely been reported in the literature. These tumors can have variable appearance on magnetic resonance imaging (MRI) due to different extents of melanin and hemorrhage. Histopathologic confirmation and a comprehensive workup to rule out extra-spinal melanoma are required to make definitive diagnosis. We present a case of a patient diagnosed with primary intramedullary spinal melanoma in his lower thoracic spinal cord who was effectively treated with surgical resection, adjuvant radiation, and adjuvant immunotherapy. Gross total resection (GTR) is most vital in the management of this spinal tumor. Although several studies have established the efficacy of immunotherapy agents in advanced malignant melanoma, the use of these agents has not been studied in primary central nervous system melanomas. This case provides insight into the diagnostic approach and treatment options for this unique malignancy.

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.

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.

Neurocutaneous Melanosis with Leptomeningeal Melanoma Involving Supratentorium and Infratentorium

Neurocutaneous melanoma is a rare congenital syndrome associated with congenital melanocytic nevi with meningeal melanosis or melanoma. The disease is aggressive and has a high propensity for leptomeningeal metastases. We present the case history of a man with neurocutaneous melanoma managed with radical excision followed by hypofractionated adjuvant radiotherapy. One year, eight months later, he had a recurrence of the condition with leptomeningeal spread and was managed with re-excision of the recurrent lesion. Although our patient was disease-free for 20 months after the initial surgery, he survived only approximately five months after the second surgery, which reflects the associated poor prognosis of the disease.

Primary central nervous system malignant melanoma with leptomeningeal melanomatosis: a case report and review of the literature

Leptomeningeal melanomatosis is an extremely rare variant of primary central nervous system (CNS) melanoma and has a poor prognosis and no standard treatment. Primary CNS melanoma is derived from the melanocytes of the leptomeninges. Here, we describe a case of a 37-year-old male who visited our hospital due to worsening headaches. Characteristic imaging findings of this tumor type include hyper-dense lesions that are enhanced by contrast medium on computed tomography and hyper-intensity on T1-weighted magnetic resonance images and iso- to hypo-intensity on T2-weighted magnetic resonance images. Imaging of the CNS in our patient showed several lesions of this type. Pathological diagnosis and exclusion of systemic melanoma are required to confirm primary CNS malignant melanoma. Partial resection of the mass in the left temporal lobe of this patient was performed, and histological analysis showed pigmentation, melanin black-45 positivity, and BRAF mutation. Because no lesions were found outside the CNS following a thorough whole-body search, he was diagnosed with primary CNS malignant melanoma with leptomeningeal melanomatosis. He was treated with whole-brain radiation and the BRAF kinase inhibitor vemurafenib. His condition worsened, and he was given the anti-programmed cell death-1 antibody nivolumab as second-line therapy. This was also unsuccessful, and he died 5 months after treatment initiation. Further studies are needed to improve treatment and prognosis of this rare but serious disease.

Two cases of primary leptomeningeal melanomatosis mimicking subacute meningitis

Primary involvement of leptomeninges with melanocytic tumours is rarely seen and its diagnosis is challenging. Here we summarise two cases of primary leptomeningeal melanomatosis presenting as subacute meningitis. Both cases have pleocytosis and high protein on cerebrospinal fluid analysis, and demonstrated atypical cells on cytology. On magnetic resonance imaging, there is diffuse leptomeningal thickening and avid enhancement of intracranial and intraspinal leptomeninges. One of them demonstrates T1 shortening due to magnetic effects of melanin, the other case is amelanotic and shows hypointensity on precontrast T1-weighted images. Both cases can be diagnosed with biopsy. In conclusion, these cases highlight the importance of the correct interpretation of cytological and magnetic resonance imaging findings in patients with atypical findings.

[Primary malignant melanoma in the brain of a 7-month-old sheep (Ovis aries f. domestica)]

A case of malignant melanoma in a sheep's brain is described for the first time. In a 7-month-old sheep that had been euthanized due to ataxia, post-mortem and histopathologic examinations were performed. Both the brain and the calvarium were heavily infiltrated with neoplastic tissue. Metastases were found in the liver and kidneys. Histomorphology confirmed the gross pathologic impression of malignancy. Congenital melanosis, which is regularly present in the meninx of sheep, could have been the origin of the malignant melanoma in the present case. The young age of the animal appears to favour this supposition. This case demonstrates that even in farm animals - including sheep - a neoplasm should be considered as a differential diagnosis in diagnostically doubtful cases.

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 cerebral malignant melanoma in insular region with extracranial metastasis: case report and review literature

BACKGROUND

Primary brain melanomas are very infrequent and metastasis outside central nervous system very uncommon. There are some cases in the literature about primary melanoma in the temporal lobe; nevertheless, the insular location has never been described.

CASE PRESENTATION

The patient presented as left insular intraparenchymal hematoma with multiple bleedings. Complementary tests did not show any tumoral nor vascular pattern in relation with these bleedings. A complete surgical resection was performed, and the diagnosis of malignant melanoma, with BRAF mutation, was obtained after histology exam. Extension studies were negative for skin or mucous melanoma. 18F-FDG PET/CT was performed and a metastatic lymph node was found. The diagnosis was primary brain melanoma with extracerebral metastasis. Dabrafenib 150 mg/12 h was the only chemotherapy during 5 months. After that, Trametinib 2 mg/24 h was added to the treatment. Eighteen months after surgery, the patient is independent, with stable situation, and without new metastasis.

CONCLUSIONS

Although malignant melanomas have poor prognosis, total surgical resection and new therapies are increasing the overall survival and improving quality of life. In a patient with suspected brain melanoma, in spite of having extracerebral metastasis, aggressive treatment may be considered.