Segmental neurofibromatosis, a subtype of neurofibromatosis type 1, is characterized by neurofibromas and/or café-au-lait spots limited to an area or segment of the body. Checkerboard pattern is a rare type of cutaneous mosaic manifestation, characterized by squares or broad ribbons of affected skin with sharp demarcation at the midline. Herein, we report the case of a patient with bilateral segmental neurofibromatosis with lentiginosis showing a checkerboard pattern. Our patient had multiple hyperpigmented macules on her entire body in a checkerboard pattern since birth. Several café-au-lait patches were observed on the left buttock and right axilla. A neurofibroma was incidentally found beneath the café-au-lait patch by histological examination, which showed ill-defined spindle cells with elongated nuclei at the deep dermis that stained positive for S-100. Based on the clinical presentation and histopathologic results, the patient was diagnosed with bilateral segmental neurofibromatosis with lentiginosis showing a checkerboard pattern.
Axilla ; Body Patterning ; Buttocks ; Dermis ; Humans ; Lentigo ; Neurofibroma ; Neurofibromatoses ; Neurofibromatosis 1 ; Parturition ; Skin

Noonan syndrome (NS) and NS-related disorders (cardio-facio-cutaneous syndrome, Costello syndrome, NS with multiple lentigines, or LEOPARD [lentigines, ECG conduction abnormalities, ocular hypertelorism, pulmonic stenosis, abnormal genitalia, retardation of growth and sensory neural deafness] syndrome) are collectively named as RASopathies. Clinical presentations are similar, featured with typical facial features, short stature, intellectual disability, ectodermal abnormalities, congenital heart diseases, chest & skeletal deformity and delayed puberty. During past decades, molecular etiologies of RASopathies have been growingly discovered. The functional perturbations of the RAS-mitogen-activated protein kinase pathway are resulted from the mutation of more than 20 genes (PTPN11, SOS1, RAF1, SHOC2, BRAF, KRAS, NRAS, HRAS, MEK1, MEK2, CBL, SOS2, RIT, RRAS, RASA2, SPRY1, LZTR1, MAP3K8, MYST4, A2ML1, RRAS2). The PTPN11 (40–50%), SOS1 (10–20%), RAF1 (3–17%), and RIT1 (5–9%) mutations are common in NS patients. In this review, the constellation of overlapping clinical features of RASopathies will be described based on genotype as well as their differential diagnostic points and management.
Congenital Abnormalities ; Costello Syndrome ; Diagnosis ; Ectoderm ; Electrocardiography ; Genitalia ; Genotype ; Heart Diseases ; Humans ; Hypertelorism ; Intellectual Disability ; Lentigo ; Noonan Syndrome ; Panthera ; Protein Kinases ; Puberty, Delayed ; Pulmonary Valve Stenosis ; Thorax

No abstract available.
Lentigo* ; Ustekinumab*

A 69-year-old man presented with a black irregular patch on his left cheek. Skin biopsy revealed lentigo maligna melanoma in situ. He was treated via partial excision of the melanoma, followed by the application of 5% imiquimod cream every other night for 6 to 8 hours. The patient experienced severe local inflammation accompanied by burning, edema, and erythema, as well as oozing and crusting. The patient discontinued using the imiquimod cream after 15 applications because of the inflammation. Depigmentation was noted in the treated area 3 months after the initiation of treatment with imiquimod cream. Histological examination using Melan-A staining of the depigmented area revealed an absence of melanocytes, which is consistent with vitiligo. The depigmented lesions improved considerably after a 5-year follow-up, and there was no recurrence of melanoma.
Aged ; Biopsy ; Burns ; Cheek ; Edema ; Erythema ; Follow-Up Studies ; Humans ; Hutchinson's Melanotic Freckle* ; Inflammation ; Lentigo* ; MART-1 Antigen ; Melanocytes ; Melanoma* ; Recurrence ; Skin ; Toll-Like Receptors ; Vitiligo

BACKGROUND: Low fluence 1,064 nm Q-switched (QS) Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser treatment, also known as laser toning, is widely used for pigmentary disorders. There has been no reliable evaluation of the effect of low fluence 1,064 nm QS Nd:YAG laser for senile lentigo. OBJECTIVE: To investigate the beneficial effect of low fluence 1,064 nm QS Nd:YAG laser in the treatment of senile lentigo on the face. METHODS: A retrospective review was conducted on patients treated only with repetitive low fluence 1,064 nm QS Nd:YAG laser. Among them, 12 patients with multiple senile lentigines before treatment were included. All side effects were recorded to assess the safety of the modality. RESULTS: Mean age was 56.1±7.8 years old and male-to-female ratio was 1:11. Mean treatment fluence was 1.62±0.16 J/cm² and mean total treatment session was 8.8±2.6. Mean interval period between each session was 28.0±11.4 days and mean treatment session to reach marked and near total improvement was 8.7±2.8. At the final visit, seven of 12 (58.3%) patients reached marked and near total improvement, and three of 12 (25.0%) reached moderate improvement. No side effects occurred. CONCLUSION: Repetitive low fluence 1,064 nm QS Nd:YAG laser treatment may be an effective and safe optional modality for senile lentigo.
Humans ; Laser Therapy ; Lentigo* ; Pigmentation ; Retrospective Studies ; Skin

Variation in human skin and hair color is the most notable aspect of human variability and several studies in evolution, genetics and developmental biology contributed to explain the mechanisms underlying human skin pigmentation, which is responsible for differences in skin color across the world's populations. Despite skin pigmentation is primarily related to melanocytes functionality, the surrounding keratinocytes and extracellular matrix proteins and fibroblasts in the underlying dermal compartment actively contribute to cutaneous homeostasis. Many autocrine/paracrine secreted factors and cell adhesion mechanisms involving both epidermal and dermal constituents determine constitutive skin pigmentation and, whenever deregulated, the occurrence of pigmentary disorders. In particular, an increased expression of such mediators and their specific receptors frequently lead to hyperpigmentary conditions, such as in melasma and in solar lentigo, whereas a defect in their expression/release is related to hypopigmented disorders, as seen in vitiligo. All these interactions underline the relevant role of pigmentation on human evolution and biology.
Biology ; Cell Adhesion ; Developmental Biology ; Extracellular Matrix Proteins ; Fibroblasts ; Genetics ; Hair Color ; Homeostasis ; Humans ; Intercellular Signaling Peptides and Proteins ; Keratinocytes ; Lentigo ; Melanocytes ; Melanosis ; Pigmentation ; Skin Pigmentation* ; Skin* ; Vitiligo

Aged ; Aged, 80 and over ; Dermatology ; Female ; Health Services Needs and Demand ; Humans ; Ichthyosis ; diagnosis ; epidemiology ; Keratosis, Seborrheic ; diagnosis ; epidemiology ; Lentigo ; diagnosis ; epidemiology ; Male ; Mass Screening ; Middle Aged ; Pilot Projects ; Poverty ; Singapore ; epidemiology ; Skin Diseases ; diagnosis ; epidemiology ; Skin Neoplasms ; diagnosis ; epidemiology ; Social Class ; Vulnerable Populations

BACKGROUND: Lentigo maligna melanoma (LMM) is a subtype of melanoma that typically develops on sun-damaged skin. LMM is estimated to comprise 4~15% of melanomas, but the prevalence is known to be relatively lower in the Korean population than in the Caucasian population. OBJECTIVE: To review the clinico-pathologic features and treatment outcomes of Korean patients with LMM. METHODS: Nineteen patients diagnosed with LMM during 2003~2015, in the Yonsei University Health System, were included in this study. The age and sex of the patients, lesion location, thickness (Breslow), stage, treatment methods, BRAF, NRAS, and KIT mutation status, and survival rates were analyzed. RESULTS: Among the 19 Korean patients, 11 were male and 8 were female. The median age was 59.2 years. The most common site was the cheek (47.4%), followed by the scalp, eyelid, nose, forehead, lip, and neck. At the time of diagnosis, 13 patients were in localized stages (5 patients, stage 0; 3 patients, stage I; and 5 patients, stage II) and 6 patients were in advanced stages (3 patients, stage III; and 3 patients, stage IV). Patients in the localized stages showed better overall survival (OS) than those in the advanced stages (p=0.012). Nine patients were treated with a wide excision, and 6 using Mohs micrographic surgery. Three patients received high-dose interferon-α therapy; 6, chemotherapy; and 4, radiotherapy. Two patients in stage 0 were treated with topical ingenol mebutate. Two patients had BRAF V600E mutation; 1, NRAS G12R mutation; and 1, KIT mutation. Median OS of the patients was 40.8 months. CONCLUSION: Our analysis provides additional information about clinical characteristics, treatment, and prognosis of LMM in Korean patients.
Cheek ; Diagnosis ; Drug Therapy ; Eyelids ; Female ; Forehead ; Humans ; Hutchinson's Melanotic Freckle* ; Lentigo* ; Lip ; Male ; Melanoma* ; Mohs Surgery ; Neck ; Nose ; Prevalence ; Prognosis ; Radiotherapy ; Retrospective Studies* ; Scalp ; Skin ; Survival Rate

No abstract available.
Fibroblast Growth Factor 7* ; Humans* ; Hyperpigmentation* ; Keratinocytes* ; Lentigo* ; Melanosis*

No abstract available.
Lentigo*