Oral Melanocytic

Vogt-Koyanagi-Harada (VKH) disease is a multisystem disorder characterized by bilateral granulomatous panuveitis resulting in serous retinal detachments, disk edema, and a sunset glow fundus development. Furthermore, it is associated with various extraocular findings, such as tinnitus, hearing loss, vertigo, poliosis, and vitiligo (1). VKH is considered to be an autoimmune disease mediated by T-cells targeting melanocyte antigen tyrosinase peptide (2). Moreover, VKH more often occurs in individuals with a genetic predisposition to the disease, including those of Asian and Hispanic heritage (3)...

Melanoma of the dog and cat poses a clinical challenge to veterinary practitioners across the globe. As knowledge evolves, so too do clinical practices. However, there remain uncertainties and controversies. There is value for the veterinary community at large in the generation of a contemporary wide-ranging guideline document. The aim of this project was therefore to assimilate the available published knowledge into a single accessible referenced resource and to provide expert clinical guidance to support professional colleagues as they navigate current melanoma challenges and controversies...

In felines, ocular and nonocular melanomas are uncommon tumors that represent a diagnostic challenge for pathologists, especially when amelanotic. To date, the immunohistochemical diagnostic panel in cats is based on specific melanocytic markers (Melan-A and PNL2) and a nonspecific but sensitive marker (S100). In human medicine, SOX-10 is reported to be a sensitive antibody for the detection of melanoma micrometastasis in the lymph node. TRP-1, an enzyme involved in melanogenesis, has recently been used in humans and dogs as a specific melanocyte marker...

Vitiligo is a chronic skin condition caused by an autoimmune response that results in the progressive loss of melanocytes and recent studies have suggested that Janus kinase inhibitors (JAKi) are emerging as a promising new treatment modality. Therefore, to assess and understand the extent of knowledge in the emerging field of JAKi use in vitiligo, a scoping review of the literature was undertaken. The reviewed articles explored a wide variety of JAKi administered either orally or topically for vitiligo. There were no injectable JAKi studied...

BACKGROUND: Data on dermatological manifestations of Costello syndrome (CS) remain heterogeneous and lack in validated description. OBJECTIVES: To describe the dermatological manifestations of CS; compare them with the literature findings; assess those discriminating CS from other RASopathies, including cardiofaciocutaneous syndrome (CFCS) and the main types of Noonan syndrome (NS); and test for dermatological phenotype-genotype correlations. METHODS: We performed a 10-year, large, prospective, multicentric, collaborative dermatological and genetic study...

Vitiligo is a skin depigmentation disease resulting from melanocyte destruction and often co-occurring with autoimmune disorders like hyperthyroidism, alopecia areata, pernicious anemia, and systemic lupus erythematosus (SLE). Although various traditional treatments exist for vitiligo, their effectiveness varies considerably. This report presents a unique case of a vitiligo patient with concomitant systemic lupus erythematosus. Remarkably, after a 30-day course of treatment with tofacitinib, complete repigmentation of the white macular rash was achieved, and there were no adverse drug reactions...

BACKGROUND: There is a strong correlation between alopecia areata (AA) and the development of white hair. The AA presents itself in many clinical manifestations of depigmented hair as the condition advances. It is uncommon for unpigmented hair to extensively regrow for more than one hair growth cycle in AA and successful conversion to pigmented hair after treatment has not yet been reported. AIM: We report two case studies involving the persistent regrowth of white hair after AA that became pigmented through treatment...

Orofacial masses or swellings are a common presenting complaint in lagomorphs. Similar gross appearances of the masses can complicate clinical interpretation, and histologic review often provides the final diagnosis. Underlying causes vary from infectious to neoplastic. Although inflammatory changes are most commonly reported, various neoplasms occur, although the prevalence of specific tumor types is relatively unknown. We reviewed retrospectively 120 cases (87.5% biopsy, 12.5% autopsy) of neoplastic and non-neoplastic orofacial masses received from January 2000-February 2023 at 2 institutions: University of Guelph, Canada (Animal Health Laboratory and Department of Pathobiology), and Finn Pathologists, United Kingdom...

Several members of the SRY-related HMG-box (SOX) protein family are implicated in tumorigenesis, metastasis, and regulation of the tumor microenvironment. SOX10, which is involved in neural crest cell migration and differentiation, has long been recognized a sensitive and specific immunohistochemical (IHC) marker in the diagnosis of melanoma in humans. However, expression of SOX10 in other tumor types has infrequently been evaluated in humans until recently and has not been thoroughly investigated in the dog...

Perivascular epithelioid cell tumor (PEComa), an uncommon mesenchymal neoplasm, arises from specialized perivascular epithelioid cells exhibiting distinct features of smooth muscle and melanocytic differentiation with unpredictable behavior. PEComa tends to occur more commonly in the uterus and kidneys; its occurrence in the liver is exceedingly rare. We presented a case of a 29-year-old woman with hepatic PEComa and evaluated the tumor with MRI, integrated 18 F-fluorodeoxyglucose (FDG), and 68 Ga-fibroblast activation protein inhibitor (FAPI) PET/CT scans at presentation...

Vitiligo is an autoimmune disease involving melanocyte-targeting T cells initiated by environmental and genetic factors. Steroids and tacrolimus have been used as topical treatments. Recently, novel topical agents targeting Janus kinase (JAK), a family of tyrosine kinases that regulates cytokine signaling, have emerged. Ruxolitinib is the first approved in vitiligo therapy. Furthermore, ritlecitinib is currently under clinical trials for oral treatment of active vitiligo. In this review, we discuss the possibility of topical JAK inhibitors as promising options for the treatment of vitiligo with regard to their mechanism of action, efficacy and safety...

Effects of butyric acid, a bacterial metabolite implicated in periodontitis progression, have never been examined on oral melanocytes. Herein, primary human epidermal melanocytes were used as a model for oral melanocytes. Results show the adverse effects of butyric acid (sodium butyrate; NaB) on them, which comprise marked cytotoxicity at higher concentrations (>1 mM) and robust differentiation at lower nontoxic concentrations. NaB did not alter MITF protein levels; however, it stimulated tyrosinase protein synthesis and inhibited tyrosinase activity, with no changes in cellular melanin...

BACKGROUND: Melanoma cancer represents the most lethal type of skin cancer originating from the malignant transformation of melanocyte cells. Almost 50% of melanomas show the activation of BRAF mutations. The identification and characterization of BRAF mutations led to the development of specific drugs that radically changed the therapeutic approach to melanoma. METHODS: We conducted a narrative review of the literature according to a written protocol before conducting the study...

Skin is a major site of cortisol bioconversion by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) enzymes which catalyze intracellular inactive cortisone into physiologically active cortisol. 11β-HSD1 is highly expressed in skin, especially in dermal fibroblasts, epidermal keratinocytes, melanocytes, and hair follicles, and plays important roles in regulating keratinocytes, fibroblast proliferation, and has roles in skin aging. Inhibition of 11β-HSD1 may reverse decreased collagen levels observed in extrinsically and intrinsically aged skin...

Primary cilia play a significant role in influencing cell fate, including apoptosis in multiple cell types. In the lesional epidermis of vitiligo patients, a reduced number of ciliated cells was observed. Our study also revealed a downregulation of oral-facial digital syndrome type 1 (OFD1) in the affected skin of vitiligo patients. However, it remains unknown whether primary cilia are involved in the control of melanocyte apoptosis. While both intraflagellar transport 88 (IFT88) and retinitis pigmentosa GTPase regulator-interacting protein-1 like (RPGRIP1L) are associated with ciliogenesis in melanocytes, only the knockdown of OFD1 , but not IFT88 and RPGRIP1L , resulted in increased melanocyte apoptosis...

In this study, we examined the cytotoxic effects of six commercial children's mouthrinses (designated as #1, #2, #3, #4, #5, and #6) and four commercial children's toothpastes (designated as #1, #2, #3, and #4) on primary human neonatal melanocytes that were used as a representative model for oral melanocytes. Mouthrinses diluted directly with culture medium (1:2, 1:5, 1:10, 1:100, and 1:1000) were added to monolayers of melanocytes for 2 min, followed by 24 h recovery, after which MTS cytotoxicity assay was conducted...

Vulvovaginal melanoma (VVM) is a rare but deadly disease, accounting for 5% of all vulvar malignancies, with a 5-yr survival rate of only 47% for all stages of the disease. VVM is a distinct subset of melanoma, with a unique genomic profile and underlying pathogenesis unassociated with sun exposure. Distinguishing these rare malignancies from very common pigmented lesions of the vulva and vagina is challenging as histologic features often overlap between entities. PReferentially expressed Antigen in MElanoma (PRAME) is a melanoma-associated protein, and immunohistochemistry (IHC) for PRAME distinguishes cutaneous, oral mucosal, and retinal melanoma from atypical nevi...

Vitiligo, the most prevalent skin depigmenting disease, is characterized by the selective loss of melanocytes, impacting patients' quality of life significantly. This autoimmune disorder progresses through a complex interplay of genetic and non-genetic factors, posing challenges in comprehending its pathogenesis and devising effective treatment strategies for achieving remission. Existing conventional therapeutic approaches, such as topical and oral corticosteroids, calcineurin inhibitors, and phototherapy, lack specificity, offer modest efficacy, and may entail potential adverse effects...

INTRODUCTION: Vitiligo is an autoimmune disorder which presents as depigmented macules due to selective loss of melanocytes. Heightened expression of Janus Kinase Signal transducers and activators of transcription (JAK STAT) pathway, which mediate cytokines action, suggest that targeting this signaling pathway may be an effective option. AREAS COVERED: A PubMed search was carried out with the broad key words 'JAK,' 'vitiligo' from 2016 to 2023. We also analyzed papers where tissue-based JAK expression was studied, with or without concomitant treatment with JAK inhibitors...

Anorectal melanoma (ARM) is an exceedingly rare and very aggressive malignancy. It originates from the melanocytic cells in the anorectal mucosa, which produces melanin. Other mucosal melanomas commonly found in the mucosa of the oral cavity, vulvovaginal, pharynx and urinary tract. Patients usually present with bleeding per rectum, perianal pain and difficulty in defaecation. Distinction of primary anorectal melanoma from other tumours of this region is difficult because of the lack of common imaging features...