Orbital melanocytoma completely resected with conservative surgery in association with ipsilateral nevus of Ota: report of a case 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.

Stereotactic radiosurgery for intracranial primary melanocytomas

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Primary orbital melanoma: A report of a case and comprehensive review of the literature

Purpose: To review the clinical features and treatment-associated outcomes of primary orbital melanoma among cases reported in the literature and to present a case treated with orbital exenteration and post-operative radiotherapy.Methods: Case reports and case series on primary orbital melanoma published in the literature between 1980 and 2020 were reviewed. Data collected included patient demographics, presenting ocular symptoms, diagnostic imaging, histology, management, and outcomes.Results: Eighty-eight cases of primary orbital melanoma were reviewed. The average age at presentation was 45 years and 58% of patients were male. The most common presenting symptoms and signs were proptosis (73%), decreased visual acuity (32%), pain (14%), diplopia (15%), and palpable mass (9%). Imaging frequently showed a well-circumscribed enhancing lesion. Diagnosis was made by histology in all cases, and orbital blue nevus was identified in 42%. In the majority of cases, treatment consisted of orbital exenteration (54%) or excision (38%). Adjuvant radiotherapy was given in 47% of cases. For the 72 patients with reported outcomes, 36% had metastases, 15% had local recurrence, and 32% died of metastatic disease. Patients who received surgery and radiotherapy had improved survival compared to those who received surgery alone (p = .01). There was no difference in survival between those who underwent orbital exenteration or excision (p = .16).Conclusions: Primary orbital melanoma is a rare malignancy and should be considered in patients with a history of unilateral proptosis and a well-defined orbital mass on imaging. Surgery remains the mainstay of treatment. Adjuvant radiotherapy may improve patient survival.

Congenital choroidal melanocytoma in a child with ocular melanocytosis

A 1-day-old child was brought to the clinic for evaluation of enlarged right eye (OD). On examination, OD showed buphthalmos with diffuse scleral melanocytosis, fleshy blackish-brown extrascleral mass with corneal extension, and secondary glaucoma. Anterior segment evaluation revealed darkly pigmented iris and fundus evaluation OD revealed a darkly pigmented choroidal lesion. The left eye was within normal limits. A clinical diagnosis of choroidal melanocytoma with ocular melanocytosis was made. Enucleation OD followed by orbital implant was performed. Histopathology showed features of diffuse ocular melanocytosis involving limbus, iris, ciliary body, choroid, sclera, optic nerve head, optic nerve sheath, along with choroidal melanocytoma with extrascleral tumour extension. We presume that choroidal melanocytoma may have arisen from ocular melanocytosis.

Intracranial meningeal melanocytoma diagnosed using an interdisciplinary approach: a case report and review of the literature

Background

Meningeal melanocytoma is a rare pigmented tumor arising from leptomeningeal melanocytes. Patients with this tumor might initially consult a dentist because a mass lesion in Meckel’s cave could manifest as dental pain and malocclusion, thereby mimicking temporomandibular disorder. The diagnostic approach, especially using imaging modalities, would be challenging in such cases unless an interdisciplinary approach is used.

Case presentation

Here, we report a case of a 39-year-old Japanese man who had a history of pain and numbness on the left side of his face and malocclusion for 3 months before the initial visit. The diagnosis was primary intracranial meningeal melanocytoma arising from Meckel’s cave.

Conclusions

The process by which the final diagnosis of meningeal melanocytoma was reached highlights the importance of collaboration between the medical and dental disciplines. This case also demonstrates that meningeal melanocytoma has a specific signal pattern on magnetic resonance imaging, including high signal intensity on T1-weighted images and low signal intensity on T2-weighted images.

Orbital melanocytoma: When a tumor becomes a relieving surprise

Purpose

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

Observations

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

Conclusion and importance

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

Orbital meningeal melanocytoma: Histological, immunohistochemical and molecular characterization of a case and review of the literature

AIMS

We provide morphological, immunohistochemical and molecular characterization of the 3rd "intermediate-grade" orbital meningeal melanocytoma, testing for the first time Vysis Melanoma FISH Probe Kit. We reviewed the literature in order to discuss the main differential diagnoses and to provide a better molecular description of these unusual tumors of difficult diagnosis and controversial management.

METHODS

Histochemical stains (Haematoxylin and Eosin, Perls, reticulin), immunohistochemistry (HMB45, p16, Melan-A, S100, EMA, Ki67, CD68), polymerase chain reaction amplification and sequence analysis (BRAF, exon 15; NRAS exons 2 and 3; c-KIT, exons 11, 13, 17, 18; GNAQ, exons 4 and 5; GNA11, exons 4 and 5) and fluorescent in situ hybridization (RREB1, 6p25; MYB, 6q23; CCND1, 11q13; CEP 6, 6p11.1-q11.1) were performed on paraffin-embedded, formalin-fixed material.

RESULTS

Histological diagnosis of "intermediate-grade" melanocytoma was supported by zonal necrosis and increased Ki67-index (12%). Immunophenotype: HMB45+(strong, >75%), Melan-A+(strong, >75%), p16+(∼20%), S100 -/+ (<5%), EMA -/+ (<5%), CD68 - (positive histiocytes). No gene mutations nor copy-number alterations were identified. The patient was asymptomatic and disease-free 3 years after total surgical excision.

CONCLUSIONS

Adequate sampling and accurate immunohistochemical characterization are important for a correct diagnosis. Molecular analysis could provide important additional information (especially for "intermediate-grade" tumors), but further data are needed.

Meningeal Melanocytes in the Mouse: Distribution and Dependence on Mitf

Summary: Melanocytes are pigment producing cells derived from the neural crest. They are primarily found in the skin and hair follicles, but can also be found in other tissues including the eye, ear and heart. Here, we describe the distribution of pigmented cells in C57BL/6J mouse meninges, the membranes that envelope the brain. These cells contain melanosomes of all four stages of development and they depend on Microphthalmia associated transcription factor (MITF), the master regulator of melanocyte development, suggesting that they are bona-fide melanocytes. The location of these pigmented cells is consistent with the location of meningeal melanomas in humans and animal models.

Significance: Here, we document and define pigmented cells in the meninges of the mouse brain and confirm that they are melanocytes. This is important for understanding the role of this cell type and for understanding primary meningeal melanoma, a rare disease that likely arises from normal meningeal melanocytes.

Dermal melanocytosis and associated disorders

PURPOSE OF REVIEW

Dermal melanocytosis is commonly seen in the newborn period and is frequently a concern to parents and providers. Four clinically distinct entities are recognized: nevus of Ota, nevus of Ito, Mongolian spots, and dermal melanocyte hamartoma. This article reviews these disorders, with special emphasis on melanocyte biology and important associated systemic disorders such as rare malignant transformations and inborn errors of metabolism.

RECENT FINDINGS

Recent findings have highlighted the increased risk of malignancy in patients with nevus of Ota, especially ocular, central nervous system, and cutaneous tumors. Although rarely seen, cutaneous melanoma occurs in association with nevus of Ito. Extensive, dark, and progressive Mongolian spots may be more likely than isolated lesions to be associated with inborn errors of metabolism, such as Hurler's disease and monosialotetrahexosylganglioside (GM1) gangliosidosis. New laser technology utilizing Q-switched alexandrite lasers has shown promise for the cosmetic improvement of dermal melanocytosis.

SUMMARY

While most dermal melanocytosis resolves by the toddler years and does not pose long-term risks to the affected individuals, some patients may have underlying associated conditions that pose significant health concerns. Pediatric care providers must be familiar with these associated conditions and refer to a dermatologist when in doubt, to confirm the diagnosis and determine appropriate follow-up care.

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

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