GNA11 Mutation in an Intracranial Melanocytoma with Orbital Involvement and Nevus of Ota

Malignant Transformation of Ocular Melanocytoma to Uveal Melanoma: A Clinicopathologic Review of Three Novel Unsuspected Cases of a Likely Under-Recognized Phenomenon, With Review of the Literature and Molecular Genetic Data

PURPOSE

To describe three cases of, and review the current knowledge regarding, malignant transformation of ocular melanocytoma (OM) to uveal melanoma (UM).

DESIGN

Retrospective clinicopathological case series and review of the literature.

METHODS

Clinical records and histopathology from three patients diagnosed with UM arising from a previously unsuspected OM were critically reviewed at a single academic institution. The patients' demographic information, medical history, presenting clinical signs and symptoms, laboratory results, ancillary (including molecular genetic) testing, and management were collected. A literature review was conducted.

RESULTS

Three novel cases were identified, totaling 18 reported cases of malignant transformation of an OM to UM. The three new cases were diagnosed histopathologically on enucleation specimens for UM, without prior clinical history of OM. Where demographic information was available, ten patients were female and six male, with an average age at presentation of 45.75 years (range 15-69 years). For patients with an initial clinical diagnosis of OM, the interval to diagnosis of melanoma was between 0.25 years and 33 years, with the most common symptoms of evolution to UM being progressive vision loss, ocular pain, and elevated intraocular pressure. Six total cases did not have a previously known history of melanocytoma.

CONCLUSION

OM is rare; malignant transformation of OM to UM is also very uncommon. The incidental histopathological observation of darkly pigmented, polyhedral, magnocellular cells adjacent to or admixed with frank melanoma resulted in immunohistochemical confirmation of a precursor OM in three unsuspected cases, mimicking somewhat the appearance of UM with abundant admixed melanophages. OM may be a precursor to UM in more instances than previously recognized, and further data, as well as careful attention by pathologists, is needed to refine diagnosis and clinical management strategies regarding patients with known OM, especially outside of the optic nerve head.

GNAQ/GNA11-Related Benign and Malignant Entities-A Common Histoembriologic Origin or a Tissue-Dependent Coincidence

Uveal melanoma (UM), recognized as the most prevalent primary intraocular malignancy in adults, is primarily driven by mutations in the GNAQ and GNA11 genes. These genetic alterations are also implicated in other conditions, which exhibit distinct morphological characteristics. In this article, we investigate the role of GNAQ and GNA11 mutations across varied disorders (e.g., UM, skin blue nevi, and hemangiomas), emphasizing the shared pathogenic mechanisms that connect them despite their differing clinical manifestations. By investigating the molecular pathways affected by these mutations, we provide insights into the potential for targeted therapies that could address not only UM but also other disorders associated with GNAQ/GNA11 mutations. Moreover, we discuss the role of SOX10-positive perivascular cells that may be implicated in the complex pathophysiology of GNAQ/GNA11-related entities. Understanding the common molecular foundation of these conditions opens new ways for research and treatment opportunities, potentially leading to more effective, personalized therapeutic strategies.

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.