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

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

BACKGROUND

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

CASE SUMMARY

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

CONCLUSION

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

Spinal Nerve Root Extradural Melanocytoma Progressing to Malignant Melanoma: A Case Report with Review of Literature

Melanocytomas are rare benign pigmented tumors arising from the leptomeninges with a very remote chance of progressing to malignant melanoma. They have a predilection for occurring in the posterior fossa or in the intradural extramedullary region of the cervical spine. We report the first case of malignant transformation of a nerve root (extradural) melanocytoma wherein immunotherapy has been added for its treatment. Only four such cases of malignant transformation of central nervous system melanocytoma have been reported in the literature. Definite diagnosis in such cases is based on immunohistochemistry evaluation. Surgical resection with adjuvant radiotherapy and immunotherapy is the recommended treatment.

Usefulness of Neuromelanin Sensitive MRI for En Plaque Meningeal Melanocytoma Involving the Cavernous Sinus: A Case Report

Intracranial meningeal melanocytoma is a rare tumor. Here, we report a case of pathologically diagnosed en plaque meningeal melanocytoma involving the cavernous sinus along with a review of the pertinent literature. A 35-year-old female presented with progressing left oculomotor nerve palsy and melanosis oculi. Radiological examinations revealed a lesion spreading in an en plaque fashion and involving the left cavernous sinus, which was hyperintense on T₁-weighted magnetic resonance imaging (MRI), and hypointense on T₂-weighted MRI. The lesion was partially excised following a histopathological diagnosis of meningeal melanocytoma. For follow-up of the residual lesion, neuromelanin sensitive MRI was introduced, and it provided better contrast between the lesion and surrounding intracranial normal tissue than conventional T₁-weighted MRI with or without gadolinium. The lesion remained stable without any growth for 3 years post-surgery. Neuromelanin sensitive MRI may be the method of choice for the follow-up of meningeal melanocytoma.

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

BACKGROUND

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

CASE DESCRIPTION

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

CONCLUSION

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

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.

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.

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

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

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.

Melanocytoma in the orbital apex

We report a case of a 49-year-old man presenting with a melanocytoma located in the orbital apex. The tumor was subtotally removed and adjuvant chemotherapy was given. The patient has remained under follow-up for the past 12 years without any evidence of recurrence. Although the characteristic neuroradiological images of the lesion prove the presence of melanin, histological examination is crucial to establish the diagnosis of melanocytoma. Besides the clinical and neuroradiological presentation, the histological, immunohistochemical, and ultrastructural findings are described. To our knowledge, this is the second published case of intraorbital melanocytoma initially confined to the orbital apex. Melanocytoma should be included in the differential diagnosis of intraorbital tumors in such a location.

The “Pirate Sign” in Fibrous Dysplasia

Fibrous dysplasia commonly involves the skull in both its monostotic and polyostotic variants. We present two cases of fibrous dysplasia involving the sphenoid wing, which were strikingly similar in their bone scan appearance. Both patients demonstrated intense increased uptake of Tc-99m MDP in a pattern reminding us of a "pirate wearing an eyepatch." We propose that this characteristic appearance of fibrous dysplasia of the sphenoid wing be called the "pirate sign." A review of the literature revealed several other pathologic conditions that have been reported to involve the sphenoid bone and should be considered in the differential diagnosis of abnormal bone tracer uptake in this region.

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.

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.

Therapy of meningeal melanocytomas

BACKGROUND

Meningeal melanocytomas are rare, benign central nervous system lesions with a high probability of recurrence. To the authors' knowledge, approximately 100 cases have been reported since 1972, when the entity first was described. In the current study, four therapies were compared with regard to local control and survival to identify which is best.

METHODS

All reported cases were reviewed with regard to extent of resection, radiotherapy, local control, and survival. If published data were incomplete, the authors were contacted for additional data. Patients were categorized by therapy: complete resection (CTR), complete resection followed by radiotherapy (CTR-RT), incomplete resection (ITR), and incomplete resection followed by radiotherapy (ITR-RT). Local control and survival were calculated using the Kaplan-Meier method. A multivariate analysis was performed including age, gender, tumor location, confirmation of extent of resection, and treatment schedule.

RESULTS

A total of 89 patients were included: 46 with CTR, 3 with CTR-RT, 23 with ITR, and 17 with ITR-RT. The 5-year local control rate was 80% after CTR, 100% after CTR-RT, and 72% after ITR-RT versus 18% after ITR (P < 0.001). The 5-year survival rate was 100% after CTR, CTR-RT, and ITR-RT, respectively, versus 46% after ITR (P < 0.001). Multivariate analysis demonstrated that therapy was the only variable that affected local control and survival significantly. In 14 patients treated with ITR-RT, RT was restricted to the tumor region. The radiation dose was 30-40 grays (Gy) in 6 patients, 45-55 Gy in 7 patients, and unknown in 1 patient. The 5-year local control rate was 86% after a dose of 45-55 Gy versus 27% after a dose of 30-40 Gy (P = 0.1).

CONCLUSIONS

CTR was found to be significantly superior to ITR with regard to both local control and survival. Outcome was significantly improved by RT after ITR. Doses of 45-55 Gy appeared to be more beneficial than doses of < or = 40 Gy.

Malignant transformation of meningeal melanocytoma: A case report

Intracranial meningeal melanocytoma is an uncommon tumor that is considered benign. We formerly reported an intracranial meningeal melanocytoma. Here we report a extremely rare case of malignant transformation of this tumor. A 49-year-old man complained of a headache. Magnetic resonance scanning revealed a mass in the left frontal region. The patient underwent gross total removal of the tomor in 1994. The histological findings showed a meningeal melanocytoma. In 1998, he underwent gamma-knife surgery for local recurrence. An additional operation was performed in 1999 became tumor growth was not stopped. The tumor was partially excised by left frontal craniotomy. Histopathological examination revealed a malignant melanoma originating from a melanocytoma. The tumor was composed of a proliferation of severely atypical melanocytoid cells with slightly irregular nuclei and prominent nucleoli, associated with necrosis and hemorrhage. Mitotic figures were encountered occasionally. After six months, he died from cerebrospinal fluid dissemination of this tumor. To our knowledge, this is the first report of malignant transformation of an intracranial meningeal melanocytoma.

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.