Tumors expressing both melanocytic and neural features can pose a diagnostic challenge to the dermatopathologist and provoke questions regarding their lineage. We report a case of a tumor arising on the right cheek of a 9-year-old boy with neurofibromatosis type 1 (NF-1). This neoplasm featured nests of non-pigmented epithelioid cells arising within a neurofibroma. The entire tumor stained strongly with S100, whereas the epithelioid population stained with MART-1, HMB-45 and MiTF. The neoplasm shows only scattered Ki-67 positivity. This tumor represents a neurofibroma with portions that have undergone melanocytic differentiation (melanocytic neurofibroma). This exceedingly rare tumor represents a distinct entity from neurotized melanocytic nevi, combined melanocytic nevi or pigmented neurofibromas and provides further evidence that melanocytes arise indirectly from ventromedial neural crest-derived Schwann cell precursors.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1111/cup.12297 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
A Cell-Based Evaluation of the Tyrosinase-Mediated Metabolic Activation of Leukoderma-Inducing Phenols, II: The Depletion of Augments the Cytotoxic Effect Evoked by Tyrosinase in Melanogenic Cells.
Biomolecules
January 2025
Division of Biochemistry, National Institute of Health Sciences, Kawasaki-ku, Kawasaki 210-9501, Japan.
Chemical leukoderma is a disorder induced by chemicals such as rhododendrol and monobenzone. These compounds possess a -substituted phenol moiety and undergo oxidation into highly reactive and toxic -quinone metabolites by tyrosinase. This metabolic activation plays a critical role in the development of leukoderma through the production of damage to melanocytes and immunological responses.
View Article and Find Full Text PDFAdvances in Immunotherapy and Targeted Therapy of Malignant Melanoma.
Biomedicines
January 2025
School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China.
Malignant melanoma (MM) is a malignant tumor, resulting from mutations in melanocytes of the skin and mucous membranes. Its mortality rate accounts for 90% of all dermatologic tumor mortality. Traditional treatments such as surgery, chemotherapy, and radiotherapy are unable to achieve the expected results due to MM's low sensitivity, high drug resistance, and toxic side effects.
View Article and Find Full Text PDFPOLYPHARMACY AND CANCER: А NEW VISION FOR SKIN CANCER PATHOGENESIS-PHOTOTOXICITY AND PHOTOCARCINOGENICITY DUE TO NITROSAMINE CONTAMINATION DURING TELMISARTAN/ TAMSULOSIN INTAKE.
Georgian Med News
November 2024
4Department of Pathology, University of Virginia, Charlottesville, USA.
The toxicokinetics of nitrosamines remain a mystery to this day, though it appears that the role of nitrosamines in potentiating the generation of mutations required for the onset of skin cancer continues to be a significant concern. Nitrosamines are mutagens, genotoxic substances, and mediators of phototoxicity/carcinogenicity, whose long-term daily usage, in the context of polypharmacy, can result in the parallel appearance of heterogeneous forms of skin cancer: keratinocytic and melanocytic. But a number of clinical observations suggest that it is the nitrosamines that potentiate the multiple occurrences of skin cancer over the years, or recurrences of skin cancer localized in areas exposed to solar radiation.
View Article and Find Full Text PDFSMARCB1-deficient malignant melanocytic uveal tumours: a new neural crest-derived tumour entity with SMARCB1-related germline predisposition.
J Pathol
January 2025
SIREDO Oncology Center (Care, Innovation and Research for Children and AYA with Cancer), Institut Curie, Université Paris Cité, Paris, France.
Rhabdoid tumours (RT) are an aggressive malignancy affecting <2-year-old infants, characterised by biallelic loss-of-function alterations in SWI/SNF-related BAF chromatin remodelling complex subunit B1 (SMARCB1) in nearly all cases. Germline SMARCB1 alterations are found in ~30% of patients and define the RT Predisposition Syndrome type 1 (RTPS1). Uveal melanoma (UVM), the most common primary intraocular cancer in adults, does not harbour SMARCB1 alterations.
View Article and Find Full Text PDFPigmented Syringomatous Carcinoma/Sweat Gland Carcinoma of the Vulva With Melanocytic Colonization: An Uncommon Presentation of a Rare Sweat Gland Neoplasm.
Am J Dermatopathol
February 2025
Departments of Dermatology and Pathology, School of Medicine, Wake Forest University, Medical Center BLVD, Winston Salem, NC.
Primary vulvar carcinomas are rare and constitute a diverse group of neoplasms. These primary tumors are typically classified based on their presumed tissue of origin or histological characteristics. Among these, carcinomas of sweat gland origin are particularly significant.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!