The World Health Organisation defines mucosal malignant melanoma as a malignant tumour of melanocytes or of melanocyte progenitors. Due to the lack of symptoms and unknown etiology, mucosal malignant melanoma may go undiagnosed. The surgeon can find it challenging to come up with a definitive treatment strategy because of its rarity and rapid spread. In this case study, a 57-year-old female patient with hyperpigmented gingiva and palate diagnosed pathologically and immunohistochemically as malignant melanoma underwent surgical excision and a modified radical neck dissection.

Pheochromocytoma or paraganglioma (PPGL) originating from chromaffin cells can produce diverse hormones in addition to catecholamines, including adrenocorticotropic hormone (ACTH). In pheochromocytoma, high levels of ACTH might not result in pigmentation as typically observed in Addison\'s disease, and patients might not exhibit the symptoms of Cushing\'s syndrome, despite ACTH-dependent hypercortisolism. A 63-year-old male patient with hypertension was admitted to our facility, and computed tomography (CT) revealed a large right adrenal tumor. Despite high plasma ACTH (700-1300 pg/mL) and serum cortisol (90-100 µg/dL) levels, no physical pigmentation or Cushingoid symptoms were observed. Urinary metanephrine and normetanephrine levels reached as high as 16.0 mg and 3.2 mg, respectively. 123I-metaiodobenzylguanidine (MIBG) scintigraphy was negative. Low-dose dexamethasone paradoxically increased ACTH and cortisol levels, indicating the potential positive feedback regulation of both hormones by glucocorticoids. The patient was diagnosed with an ACTH-producing pheochromocytoma and underwent successful laparoscopic surgery to remove the adrenal tumor under the intravenous administration of a high-dose α-blocker and hydrocortisone. The levels of ACTH, cortisol, and urinary metanephrine/normetanephrine returned close to normal after tumor removal. We report a rare case of pheochromocytoma with extremely high ACTH/cortisol production but without pigmentation or Cushingoid symptoms. We also reviewed previous reports of ACTH-producing PPGL regarding the paradoxical regulation of ACTH/cortisol by glucocorticoids, pigmentation, Cushingoid symptoms, and negativity of 123I-MIBG scintigraphy.

Skin color classification can have importance in skin health, pigmentary disorders, and oncologic condition assessments. It is also critical for evaluating disease course and response to a variety of therapeutic interventions and aids in accurate classification of participants in clinical research studies. A panel of dermatologists conducted a literature review to assess the strengths and limitations of existing classification scales, as well as to compare their preferences and utilities. We identified 17 skin classification systems utilized in dermatologic settings. These systems include a range of parameters such as UV light reactivity, race, ethnicity, and degree of pigmentation. The Fitzpatrick skin type classification is most widely used and validated. However it has numerous limitations including its conflation with race, ethnicity, and skin color. There is a lack of validation data available for the remaining scales. There are significant deficiencies in current skin classification instruments. Consensus-based initiatives to drive the development of validated and reliable tools are critically needed.

BACKGROUND: Hyperpigmented scars, particularly in exposed body areas, can be difficult to conceal and may evoke psychological distress. While the precise causes of scar dyschromia are not fully understood, alterations in melanogenic activity appear to hold more significance than changes in melanocyte quantity. Current treatments encompass laser interventions. However, it is essential to consider their costs and potential complications in relation to their limited proven effectiveness. Fat grafting has gained interest as a scar modulation technique due to its regenerative properties, and its efficacy in reducing scar hyperpigmentation is currently under investigation.
METHODS: A systematic review and meta-analysis was reported according to PRISMA guidelines. PubMed, Embase, and Cochrane Library databases were accessed. PROSPERO registration number is CRD42023457778. The primary outcome was a change in scar pigmentation after fat grafting. Pigmentation changes after fat grafting were calculated using the standardized mean difference (SMD) between baseline and postoperative scores according to POSAS and VSS scales. Bias assessment was conducted according to the National Institute for Health and Clinical Excellence quality assessment tool.
RESULTS: A total of 8 articles meeting inclusion and exclusion criteria were identified, involving 323 patients with hyperpigmented scars treated with fat grafting. A significant difference in scar pigmentation was noted after treatment with fat grafting according to observers\' ratings, with a SMD of - 1.09 [95% CI: - 1.32; - 0.85], p<0.01. The SMD for patient-reported scar pigmentation after treatment with fat grafting was - 0.99 [96% CI: - 1.31; - 0.66], p<0.01. Four studies provided objective measurements of melanin changes after fat grafting and revealed inconsistent findings compared to subjective observations.
CONCLUSIONS: Fat grafting shows promise in ameliorating hyperpigmented scars based on subjective assessments, but further corroborating evidence from objective measures is required.
METHODS: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Objective: Metformin has recently been demonstrated to have an anti-melanogenic activity. Nevertheless, clinical evidence of the effectiveness of metformin in melasma is lacking. The objective of this study was to assess the efficacy and safety of metformin in the treatment of melasma. Methods: MEDLINE, Embase, PubMed, Cochrane Library (CENTRAL), Scopus, CINAHL, and grey literature databases were searched to 4 October 2022 and updated on 26 February 2023. Randomized controlled trials (RCTs), quasi-RCTs, observational studies, case series, and case reports investigating the efficacy and safety of metformin for melasma were included. The Melasma Area Severity Index (MASI) scores that changed from baseline were pooled using fixed-effects model and expressed as standardized mean differences (SMDs) and 95% confidence intervals (CIs). Results: Three RCTs including 140 patients with melasma were included. The results demonstrated that after 8 weeks, 15% topical metformin significantly reduced the Melasma Area Severity Index (MASI) score compared to placebo (1 trial; n = 60; MD, -0.56; 95% CI, -1.07 to -0.04; p = 0.034). Furthermore, when compared to triple combination cream (TCC), 30% topical metformin demonstrated similar efficacy in reducing the MASI score after 8 weeks (2 trials; n = 80; MD, 0.19, 95% CI, -0.25 to 0.63; p = 0.390). Patients using 30% topical metformin had fewer adverse events compared to TCC users, although no statistical difference was found. Conclusion: Topical metformin was as effective as triple combination cream (TCC) in decreasing changes in the MASI score in patients with melasma, with minimum adverse events. Further studies with larger sample sizes, longer follow-up times, and well-designed trials are required. Systematic Review Registration: Identifier PROSPERO (CRD42022351966).

Laccase genes produce laccase enzymes that play a crucial role in the production of lignin and oxidation reactions within plants. Lignin is a complex polymer that provides structure and toughness to the cell walls of numerous fruit plants. The LAC genes that encode laccase enzymes play vital roles in plant physiology, including the synthesis of pigments like PA that contribute to the colors of fruits, and in defending against pathogens and environmental stresses. They are crucial for fruit development, ripening, structural maintenance in plants, and adaptation to various environmental factors. As such, these genes and enzymes are essential for plant growth and development, as well as for various biotechnological applications in environmental remediation and industrial processes. This review article emphasizes the significance of genes encoding laccase enzymes during fruit growth, specifically pertaining to the strengthening of the endocarp through lignification. This process is crucial for ensuring fruit defense and optimizing seed scattering. The information gathered in this article will aid breeders in producing future fruit-bearing plants that are resistant to disease, cost-effective, and nutrient-rich.

We report the clinical and pathologic features of a patient with breast carcinoma, who developed clinically visible pigmented skin lesions during the course of the disease. The combination of clinical pigmentation, histological pagetoid epidermal spread, and considerable melanin pigment within tumour cells lead to a misdiagnosis of melanoma. This case provides a striking example of the ability of epidermotropic breast carcinoma to mimic melanoma. A literature review is also reported.

BACKGROUND: A smile is considered one of the most important soft skills in social interaction. And discolored teeth may effect this. It is known that some photosensitizer agents (PS) used in photodynamic therapy (PDT) during root canal treatment could play a significant role in tooth color change, and thus the main objective of this systematic review is to address whether performing PDT can influence tooth color change and to synthesize the most effective methods to remove PS from the root canal system.
METHODS: This study followed the PRISMA 2020 statement, and the protocol was registered at the Open Science Framework. Two blinded reviewers searched five databases up to November 20th, 2022: Web of Science, PubMed, Scopus, Embase, and the Cochrane Library. The eligibility criteria were studies that investigated tooth color change after PDT in endodontics.
RESULTS: A total of 1695 studies were retrieved, and 7 were included in the qualitative analysis. All the included studies were in vitro evidence and investigated five different PS: methylene blue, toluidine blue O, malachite green, indocyanine green, and curcumin. Besides curcumin and indocyanine green, the remaining agents all caused tooth color change, and no method employed was effective in fully removing these PS from inside the root canal system CONCLUSIONS: Even though the findings showed that curcumin and indocyanine green did not influence tooth color change, the present evidence should be interpreted with caution since it is based on laboratory studies with questionable methods, and all efforts should be employed to avoid this undesirable side effect during clinical practice.

Decorative tattooing is a very widespread and constantly increasing practice, especially among young people.
Here, we report a case study of melanoma occurring on a tattoo on the left arm and provide an overview of all cases reported so far.
A systematic literature search of publications was conducted from inception to September 2021 via Medline (PubMed), Scopus and Google Scholar, in order to identify all cases of primitive melanomas arising on tattoos.
In total, 35 cases (32 males, three females) of melanoma arising on tattoos on skin were identified. Interestingly, most melanomas occurred on dark blue (10/35), black (12/35) or blue tattoos (3/35).
Due to the low number of melanoma cases arising on tattoos, it is not possible to confirm whether tattoos play a cancerogenic role. However, tattooing may make it more difficult to detect and monitor pigmented lesions, potentially delaying the diagnosis of cutaneous malignancies. Patients at high risk of melanoma should be warned about the risks associated with such procedures.

BACKGROUND: Congenital melanotic macule of the tongue (CMMT) has been described as a distinct entity, despite its unknown etiology. However, the diagnosis and management of affected newborns may challenge clinicians and pediatric dentists.
METHODS: We document here the clinicopathological findings of two additional cases of CMMT. A literature review of CMMT reports identified across PubMed, Web of Science, Embase, and Scopus was also conducted.
RESULTS: The patients, 2- and 4 month-old Venezuelan boys, respectively, presented at birth with a single or multiple dark-brown-pigmented macule exclusively on the dorsum of the tongue. Histopathological features revealed increased melanin pigmentation in the basal epithelial layer with overlying hyperkeratosis and pigment-laden subepithelial macrophages with normal morphological appearance. Nine studies comprising 17 cases of CMMT have been described hitherto. Most cases were from the USA and France (n = 6 each). Twelve (70.6%) patients were males, eight (50%) were white, and median age was 2.7 months. CMMT presented as brownish to black, solitary or multiple pigmentations located in the right or left region of the dorsum of the tongue, ranging in size from 3.0 to 30.0 mm.
CONCLUSIONS: An important feature for the diagnosis of CMMT is the information about the manifestation at birth and consequent proportional growth. This report intends to draw the attention of pediatricians and dentists to this apparently underdiagnosed condition for decision-making and management of affected newborns.