Preface; Contents; Contributors; 1: Melanocytes of the Nail; Introduction; History; Developments; Outlook: Future Developments; References; 2: Epidemiology of Melanonychias; References; 3: Clinical Evaluation: Clinical Features, Worrisome Signs, and the ABCDEF Rule; Introduction; Epidemiology; History of the Diagnosis of Subungual Melanoma; Differential Diagnosis; Patient History; Clinical Examination; The ABCDEF Rule; Limitations of the Clinical Evaluation of LM; Pediatric LM; References; 4: Dermoscopy of the Nail Plate, Nail Matrix, and Nail Bed; Dermoscopy of the Nail Plate.

Clinical Features Organisms; Trauma; Staining; Neoplasms; Diagnostic Clues; References; 10: Histological Analysis of the Nail Plate in the Diagnosis of Melanonychia and Other Nail Pigmentation; Introduction; Histological Features in Nail Plate Samples; References; 11: Biopsy; Introduction; Indications for Biopsy; Anatomy of the Nail Unit; Hemostasis and Anesthesia; Preoperative Preparation; Procedure; Exposure and Visualization of the Nail Matrix; Complete or Partial Nail Avulsion; Tangential Shave Nail Matrix Biopsy; Three-Millimeter Punch Biopsy Excision.

Lentigo and Nevus of the Matrix Diagnosis; Differential Diagnosis; Treatment of Nail Lentigo and Nevi; Outlook: Future Developments; References; 7: Subungual Melanoma; Introduction; Epidemiology; History; Clinical Features; Melanonychia Characteristics; Width; Shape; Color; Location; History; Other Findings; Diagnostic Clues; Dermoscopy; Biopsy; Histopathology; Treatment; References; 8: Melanonychia in Children; Introduction; Epidemiology; History; Clinical Features; Diagnostic Clues; References; 9: Non-melanocytic Melanonychia; Introduction; Epidemiology.

LentigoNail Matrix Nevus; Blue Nevi of the Nail Matrix; Melanoma of the Nail Matrix; Diagnostic Clues; References; 5: Hypermelanosis (Melanocyte Activation); Introduction; Epidemiology; History; Clinical Features; Physiological Causes; Iatrogenic Causes; Local or Regional Causes; Dermatological Causes; Pathogenic Causes; Systemic Causes; Other Causes; Diagnostic Clues; History; Physical Examination; Dermoscopy; Diagnostic Algorithm; References; 6: Lentigo and Nevus; Introduction; History; Development; Prevalence; Cause; Clinical Pattern; Significance.

Technique Dermoscopic Patterns Observed on the Nail Apparatus; Nail Plate Surface; Free Edge of the Nail Plate; Periungual Area; Pseudo-Hutchinson's Sign; Micro-Hutchinson Sign; Hutchinson's Sign; Patterns Observed According to the Diagnosis of LM; Hypermelanosis; Lentigo; Nevi of the Nail Matrix; Melanoma of the Nail Matrix; Differential Diagnosis; Subungual Hematoma; Onychomycosis; Pigmented Bowen's Disease; Dermoscopy of the Nail Matrix and Nail Bed; History; Clinical Features; Intraoperative DNMB; Patterns of DNMB Observed According the Diagnosis of LM; Hypermelanosis.

The purpose of this book is to guide the dermatologist and the general physician in the differential diagnosis and treatment of melanonychias. Melanonychia is a longitudinal pigmentation of the nail and it is considering a common presenting problem in general dermatology. The differential diagnosis varies from subungual hematoma to a fungal infection to a melanocytic lesion (hypermelanosis, lentigo, nevus, and melanoma) among others. Melanonychia may also indicate an early stage of nail melanoma, and its diagnosis remains a challenge among dermatologist. A recent publication on Dermatologists accuracy in early diagnosis of melanoma of the nail matrix showed that in situ melanoma of the nail matrix is very difficult for dermatologists to diagnose, regardless of the level of their experience. On Melanonychias the reader will find a complete discussion about all the most important topics on this condition, since its basic aspects (such as nail anatomy and epidemiology) until applied topics (including clinical features, nail biopsy and treatment).