儿童纵行黑甲皮肤镜模式分析

目的了解儿童纵行黑甲的皮肤镜特点,探索通过皮肤镜模式分析诊断儿童纵行黑甲的方法。方法收集2013年6月—2015年9月就诊于首都医科大学附属北京儿童医院皮肤科的50例纵行黑甲患儿,分析其术前皮肤镜模式,对其中42例患儿行手术治疗,分析其术中皮肤镜模式。结果术前皮肤镜检查为灰色模式的8例患儿,均未行手术治疗,行手术治疗的42例患儿,术前甲板皮肤镜显示棕色条带的4例术中皮肤镜为棕色模式,组织病理证实为雀斑样痣。术前皮肤镜显示黑色条带的7例,术中表现为规则的棕色模式伴有色素球及色素斑,组织病理证实为甲母痣。术前显示规律的棕色线条组成的条带18例,术中皮肤镜为规则的棕色模式伴有色素球14例,规则棕色模式4例,组织病理分别证实为甲母痣和雀斑样痣。术前显示规律的棕色线条组成的条带伴色素球13例,术中皮肤镜为规则的棕色模式伴有色素球,组织病理证实其中12例为甲母痣,1例为黑素细胞活化。结论术前及术中皮肤镜检查及模式分析对儿童纵行黑甲的诊断具有显著意义。     

Automated evaluation system of dermoscopic images of longitudinal melanonychia: Proposition of a discrimination index for detecting early nail apparatus melanoma

The prognosis of nail apparatus melanoma is generally poor because of difficulty in early stage diagnosis. Most nail apparatus melanomas occur as longitudinal melanonychia, and criteria and algorithms for dermoscopy diagnosis of longitudinal melanonychia have only recently been proposed. However, as with any clinical diagnosis, the diagnosis based on dermoscopy is to some extent subjective. Our goal is to develop an automated dermoscopic screening system for longitudinal melanonychia and to propose a novel objective and quantitative index for discriminating early nail apparatus melanoma from benign longitudinal melanonychia including melanocytic nevus. We propose an automatically calculated index representing degrees of color variegation in dermoscopic images of longitudinal melanonychia. Dermoscopy images of six cases of early stage nail apparatus melanoma and 25 cases of benign longitudinal melanonychia were analyzed with our screening system and a threshold of melanoma discrimination index was determined. This single melanoma discrimination index diagnosed early nail apparatus melanoma with 100% sensitivity and 92% specificity. The automatically calculated index proposed in the present study is valuable for managing longitudinal melanonychia. The results suggest that the degree of color variegation is essentially different between early nail apparatus melanoma and benign longitudinal melanonychia including melanocytic nevus of the nail apparatus.     

Dermoscopy of the nail bed and matrix to assess melanonychia striata

Melanonychia striata represents a diagnostic dilemma for dermatologists. The use of dermoscopy to assess the nail has advantages over clinical examination. However, when compared to skin lesions, it gives fewer details. We describe two cases of melanonychia striata submitted to dermoscopic examination of the nail bed and matrix. This is a new procedure that enables observing dermoscopic characteristics that are not visualized in the nail plate, thus, providing additional information.     

Spontaneous Regression of a Nail Matrix Melanocytic Nevus in a Child

A 14‐year‐old Hispanic boy presented with a 0.25‐mm wide, sharply demarcated, dark brown band of longitudinal melanonychia of the left thumbnail. A clinical diagnosis of nail matrix nevus was made and the boy was scheduled for follow‐up. The band showed proximal fading after 6 months and had completely faded after 11 months, with the proximal nail fold showing small dark brown dots on dermoscopy. We documented the spontaneous regression of melanonychia over 11 months.     

Perioperative confocal microscopy of the nail matrix in the management of in situ or minimally invasive subungual melanomas

Background Although dermoscopy of the nail plate is helpful to discriminate between benign and malignant causes of nail pigmentations, there remain ambiguous cases in which a matricial biopsy is required. When a subungual melanoma is diagnosed histopathologically, a complementary surgical treatment is performed secondarily, the duration of postoperative disability being accordingly prolongated. Objectives The purpose of our study was to evaluate the feasibility of an intraoperative diagnosis by reflectance confocal microscopy (RCM). Patients and methods Our series included nine consecutive patients who underwent a matricial biopsy for an acquired melanonychia (one benign lentigo and eight melanomas). RCM examination was performed in vivo on the nail matrix after reclination of the nail plate, and/or ex vivo on the fresh tissue biopsy. RCM data were compared with histopathology. Results There was a good correlation between confocal and histopathological features. Seven melanoma cases were unequivocally diagnosed intraoperatively according to the confocal features, whereas the lentigo was correctly classified as a benign lesion according to RCM. The remaining lesion could not be unequivocally classified by RCM and corresponded histopathologically to an early melanoma that required immunostaining to be diagnosed. Conclusions Intraoperative RCM examination of the nail matrix is an efficient diagnostic approach of melanonychia striata that permits an extemporaneous diagnosis of malignancy and therefore a one-step surgical treatment of in situ or minimally invasive melanoma, reducing dramatically the duration of postoperative disability.     

Key point in dermoscopic differentiation between early nail apparatus melanoma and benign longitudinal melanonychia

Longitudinal melanonychia presents in various conditions including neoplastic and reactive disorders. It is much more frequently seen in non-Caucasians than Caucasians. While most cases of nail apparatus melanoma start as longitudinal melanonychia, melanocytic nevi of the nail apparatus also typically accompany longitudinal melanonychia. Identifying the suspicious longitudinal melanonychia is therefore an important task for dermatologists. Dermoscopy provides useful information for making this decision. The most suspicious dermoscopic feature of early nail apparatus melanoma is irregular lines on a brown background. Evaluation of the irregularity may be rather subjective, but through experience, dermatologists can improve their diagnostic skills of longitudinal melanonychia, including benign conditions showing regular lines. Other important dermoscopic features of early nail apparatus melanoma are micro-Hutchinson's sign, a wide pigmented band, and triangular pigmentation on the nail plate. Although there is as yet no solid evidence concerning the frequency of dermoscopic follow up, we recommend checking the suspicious longitudinal melanonychia every 6 months. Moreover, patients with longitudinal melanonychia should be asked to return to the clinic quickly if the lesion shows obvious changes. Diagnosis of amelanotic or hypomelanotic melanoma affecting the nail apparatus is also challenging, but melanoma should be highly suspected if remnants of melanin granules are detected dermoscopically.     

Melanonychia striata: clarifying behind the Black Curtain. A review on clinical evaluation and management of the 21st century

Melanonychia striata is characterized by a tan, brown, or black longitudinal streak within the nail plate that runs from the proximal nail fold to the distal part of the nail plate. Melanonychia striata is due to increased activity of melanocytes or melanocytic hyperplasia in the nail matrix with subsequently increased melanin deposition in the nail plate. The most common cause of melanonychia striata associated with melanocytic activation is ethnic melanonychia which occurs in dark-skinned individuals. Other causes of melanonychia striata related to melanocytic activation include pregnancy, chronic local trauma, infections, medications, dermatological disorders, endocrine disorders, alkaptonuria, hemochromatosis, porphyria, graft-vs-host disease, Peutz-Jeghers syndrome, and Laugier-Hunziker syndrome. Causes of melanonychia striata associated with melanocytic hyperplasia include nail matrix melanocytic nevus, nail lentigo, and nail apparatus/subungual in situ and invasive melanoma. In most cases, melanonychia striata is a benign condition, especially in children. Consequently, most investigators advocate a wait-and-see approach. Nail apparatus/subungual melanoma should be suspected if there is an abrupt onset after middle age, personal or family history of melanoma, rapid growth, darkening of a melanonychia band, pigment variegation, blurry lateral borders, irregular elevation of the surface, a bandwidth >3 mm, proximal widening, associated nail plate dystrophy, single rather than multiple digit involvement, and periungual spread of pigmentation onto the adjacent cuticle and/or proximal and/or lateral nail folds (Hutchinson sign). Prolonged follow-up is mandatory for early detection of possible malignant changes.     

Fungal melanonychia

Melanonychia is characterized by tan, brown, or black pigmentation within the nail plate. Fungal melanonychia is rare and may simulate longitudinal melanonychia caused by melanocytic lesions. We report six cases of fungal melanonychia which were confirmed histopathologically or mycologically. On culture, Candida and/or Aspergillus species were isolated in four patients. The nail pigmentation improved after treatment with antifungal agents in all cases, but one patient experienced a new lesion on another nail after cessation of treatment. Fungal infection should be considered as a cause of melanonychia, and fungal melanonychia should be differentiated from the melanonychia caused by melanocytic lesions, particularly by subungual melanoma.     

Dermoscopic examination of nail pigmentation

BACKGROUND: Diagnosis of longitudinal melanonychia is usually difficult, and neither a single clinical criterion nor a combination of symptoms currently can be used to clearly distinguish malignant from benign bandlike pigmented nail lesions. Biopsy is painful and often leaves definitive dystrophic scars. OBJECTIVES: To describe and evaluate dermoscopic patterns associated with longitudinal nail pigmentation. PATIENTS AND METHODS: A total of 148 unselected consecutive cases of longitudinal melanonychia were included over a period of 4 years (20 melanoma, 37 nevi, 16 drug-induced nail pigmentation, 45 nail apparatus lentigo of various types, 8 ethnic-type nail pigmentation, and 22 subungual hemorrhages). All patients were recruited from the dermatology unit outpatient clinic of the H?tel Dieu de Lyon. All cases were photographed in vivo under oil immersion (dermoscopy). Patterns were recorded prior to final pathologic diagnosis. An independent biostatistics unit performed statistical evaluation using 7 semiologic patterns. RESULTS: Melanoma cases were significantly associated with a brown coloration of the background and the presence of irregular longitudinal lines (P =.001). Blood spots were mostly observed in subungual hemorrhages (P =.001); however, their presence could not rule out melanoma. Micro-Hutchinson sign was observed only in melanoma, but its rare occurrence did not allow any statistical evaluation of its specificity. Nail apparatus nevi were significantly associated with a brown coloration of the background and the presence of regular lines (P =.001). Nail apparatus lentigo, ethnic-type pigmentation, and drug-induced pigmentation were significantly associated with homogeneous longitudinal thin gray lines and gray coloration of the background (P =.001). Microscopic longitudinal grooves were unspecific, occurred in several conditions, and were associated with any type of ungual discoloration. CONCLUSIONS: We believe that dermoscopic examination of the nail plate in cases of longitudinal melanonychia provides useful information that could help clinicians to more accurately decide if a nail apparatus biopsy should be performed; however, histopathologic diagnosis remains the gold standard in doubtful cases.     

Melanonychia: diagnosis and treatment

Melanonychia should be a term restricted to the presence of melanin in the nail unit. To be able to understand the process of melanin deposition in the nail plate, the nail apparatus and its melanocyte system are described. The different causes responsible for a black nail are reviewed, enabling the clinician to pick out those cases that are highly suspicious of being a malignant condition. Their differential diagnosis is also considered, with special attention to Hutchinson's sign. The second part of the article deals with the management of longitudinal melanonychia, including history, clinical examination, nail plate sampling, and when and how to perform a biopsy. Finally, pathology and subungual melanoma treatment are briefly reviewed.     

Nail matrix biopsy of longitudinal melanonychia: diagnostic algorithm including the matrix shave biopsy

Longitudinal melanonychia (LM) may represent nail matrix melanocyte activation (defined as a normal number of melanocytes with increased production of melanin), benign hyperplasia, or melanoma, in addition to multiple nonmelanocyte pathologies, including hemorrhage and infection. This article details an algorithmic approach to LM, including a careful history and physical examination, dermoscopy, and ability to sample the matrix using 3 biopsy techniques, a 3-mm punch excision, a lateral longitudinal excision, and a matrix shave biopsy. Facility with all 3 techniques will allow the physician to procure appropriate nail matrix specimens for diagnosis.     

Melanonychia following mohs surgery for recurrent squamous cell carcinoma in situ of the nail bed

BACKGROUND: Longitudinal melanonychia (LM) is characterized by the appearance of a longitudinal pigmented band in the nail plate. Melanonychia can occur from many causes, including racial predisposition, trauma, drugs, pregnancy, Addison disease, Peutz-Jeghers syndrome, Laugier-Hunziker syndrome, Bowen disease, onychomycosis, benign nail matrix nevi, and melanoma. OBJECTIVE: We present a case of diffuse melanonychia developing several months following Mohs surgery for a human papillomavirus-induced recurrent squamous cell carcinoma in situ of the nail bed. CONCLUSIONS: This case illustrates the diagnostic dilemma in determining the etiology of the melanonychia and considers the differential diagnosis.     

“Dots and lines”: A melanonychia striata in regression: Report of a case

A 2‐year‐old Caucasian boy with melanonychia striata with multiple striking pits on the nail plate of one fingernail is described. Nail disorders often pose diagnostic and therapeutic challenges for clinicians, especially melanonychia striata, because of the fear of a subungual melanoma. Only a few childhood cases of melanonychia striata have been described, and the multiple pits are even less common. Dots distributed along melanotic lines is a finding referred to as “dots and lines” and can be a sign of regression of melanonychia in childeren.     

Common disorders and diseases of the nails. Anatomy, physiology, disorders, clarification and therapy

Disorders of anatomical variants of the nails are often seen in clinical practice. Their correction identification and interpretation are essential dermatological skills. The increasing emphasis on aesthetic considerations in dermatology means that even the slightest nail changes may assume significance for their patients. In order to skillfully evaluate nails, one must be familiar with the terminology and classification of nail disorders. The nail plate, nail bed and periungual tissue may also be affected. Longitudinal melanonychia is especially important as a possible clue to subungual melanoma.     

Transient, transverse melanonychia associated with Graves disease and acute hepatitis

Melanonychia is a black, tan, or brown streak within the nail plate subsequent to activation of melanocytes in the nail matrix. We present a case of a Haitian girl who presented with transverse melanonychia involving all 10 fingernails in the setting of hyperthyroidism and acute liver injury. Melanonychia has been described only one time in the literature in the setting of hyperthyroidism though this patient also underwent radium treatment which could have led to nail changes.     

Longitudinal melanonychia (melanonychia striata): diagnosis and management

Longitudinal melanonychia presents a difficult clinical challenge because subungual melanoma must always be included in the differential diagnosis and because the cause of longitudinal melanonychia is usually not apparent. Accordingly, biopsy is often necessary to establish the cause. This review attempts to expedite management by providing suggestions for the examination of patients with this disorder. The causes of longitudinal melanonychia are enumerated and clues to arrive at the various causes are discussed. Similarities between longitudinal melanonychia and subungual melanoma are discussed in an effort to clarify their differences and similarities; clues to the diagnosis of subungual melanoma are also discussed. Various biopsy techniques applicable to longitudinal melanonychia are considered and the indications for different surgical approaches are emphasized. The importance of the pathologist in interpreting nail biopsy specimens is emphasized.     

Nail bed onychomatricoma

Onychomatricoma is a rare tumor originating from the nail matrix, and, in rare conditions, from the ventral aspect of the proximal nailfold. Here we report a rare case of a 51‐year‐old man presenting with melanonychia mainly involving the distal nail plate. Histopathologic examination showed typical findings of onychomatricoma mainly involving the nail bed, while the nail matrix was largely uninvolved. We also identified fungal infection in a focal area of the distal nail plate. Our findings indicate that onychomatricoma can develop in the surrounding epithelial tissue of the nail unit, including the nail bed, and suggest that fungal infection may represent a secondary phenomenon of onychomatricoma.     

几种甲病诊疗的思考

甲病种类繁多,近年其诊断与治疗取得一些进展,但仍面临诸多挑战,如纵行黑甲、罕见的甲单元特异性肿瘤、甲营养不良等。纵行黑甲存在黑素瘤可能,而活检与手术本身是肢端黑素瘤的诱发因素,因此是否手术以及如何把握手术原则很重要。此外,在诊疗过程中应结合年龄、临床评估、皮肤镜表现以及病理检查进行评估,最终做到恶性黑甲不漏诊,良性黑甲...     

In situ melanoma of the nail unit in children: report of two cases in fair-skinned Caucasian children

Nail melanoma in children is rarely reported in the literature, and all of the published cases were diagnosed in dark-skinned phototypes or in Asians. We report two cases of in situ nail matrix melanoma presenting as longitudinal melanonychia (LM) in fair-skinned children of Italian origin. Nail plate dermatoscopy revealed a brown background with lines of irregular color, spacing, and thickness in both cases. Histopathology of the excised lesions showed melanoma in situ. Clinical, dermatoscopic, and pathological criteria that permit clear differentiation of benign melanocytic activation or proliferation from nail matrix melanoma are not established for children. The presence of a pigmented band of a single nail in a child usually represents a problem for clinicians, because the clinical and dermatoscopic features that are considered possible indicators of nail unit melanoma in adults are frequently observed in benign melanocytic hyperplasia and nevi in children. There is therefore the need to find parameters useful for clinical and dermatoscopic diagnosis in childhood nail pigmentation and to reach a consensus on management of children with a band of LM.     

Onychocytic matricoma presenting as pachymelanonychia longitudinal. A new entity (report of five cases)

Among the tumors of the epidermal appendages, only rare tumors have been proved as differentiating in the direction of the nail. Beside onychomatricoma, we report a new matrical tumor of the nail: onychocytic matricoma (acanthoma of the nail matrix producing onychocytes). The main differential diagnosis of onychocytic matricoma is seborrheic keratosis. However, if attention is paid to the nature of the different layers of the tumor and the peculiar microanatomy of the nail matrix, the differentiation is not difficult. Onychocytic matricoma is a localized (monodactylous) longitudinal melanonychia which is slightly raised. The term pachymelanonychia is used to define the 2 clinical features of the tumor. Pachyonychia indicate a localized thickening of the nail plate, and melanonychia indicate its longitudinal pigmented band. Onychocytic matricoma is composed of a basal compartment with a varying admixture of prekeratogenous cells and keratogenous cells. Endokeratinization originating in the deep portion of the tumor and nests of prekeratogenous and keratogenous cells in concentric arrangement are a characteristic feature. Three major patterns can be identified as follows: acanthotic, papillomatous, keratogenous type with retarded maturation. Given the peculiar thickening of the nail plate observed both in pigmented onychomatricoma and onychocytic matricoma, the term pachymelanonychia longitudinal could be proposed to specify clinically these 2 lesions, which the clinician sometimes mistakes for melanoma.