Pigment streaks in the nail plate due to secondary malignant melanoma

We describe two patients with pigment streaks in the nail plate due to secondary malignant melanoma in the nail matrix.     

Surgical anatomy of the nail apparatus

Nail surgery is an integral part of dermatologic surgery. An in-depth knowledge of the anatomy, biology, physiology, and gross pathology of the entire nail unit is essential. In particular, knowledge of nail histopathology is necessary to perform diagnostic nail biopsies and other nail procedures correctly.     

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.     

Atypical fibroxanthoma-like amelanotic malignant melanoma: A case report and literature review

Atypical fibroxanthoma (AFX)-like malignant melanoma is very rare. Here, we report a case of amelanotic AFX-like melanoma in a 72-year-old Taiwanese woman presenting with two separate, asymptomatic, enlarging erythematous nodules within a large hypopigmented patch on her left cheek. Histologically, both lesions showed cellular nodules in the reticular dermis separated from the overlying flattened epidermis by a zone of solar elastosis or fibrosis. The tumor consisted of sheets of atypical epithelioid cells arranged in a vague nesting pattern, as well as many atypical large or gigantic cells with one or more, large hyperchromatic, vesicular, or pleomorphic nuclei with prominent nucleoli, and moderate-to-abundant eosinophilic or foamy cytoplasm. Focal intraepidermal proliferation of atypical melanocytes with a pagetoid pattern was found only in the periphery of the main tumor. The tumor cells were moderately to strongly positive for S-100, Melan-A, and HMB-45. The pleomorphic giant cells were focally CD68-positive but CD163-negative. The patient underwent tumor excision followed by radiotherapy due to the narrow surgical margins. A sentinel lymph node biopsy revealed no metastasis of the melanoma. This case illustrates the importance of scrutinizing any subtle proliferation of atypical melanocytes in the epidermis in an AFX-like tumor in order to avoid misdiagnosis.     

Diseases of the generative nail apparatus. Part II: nail bed

Nail bed insults may affect the resultant nail product in a number of ways. If focal in nature, the severity and duration of the insult will determine the appearance of the nail product. Widespread insults may alter the size, shape or colour of the nail plate. Nail bed insults tend to present with more immediacy than nail matrical insults, as there is no need to wait until the nail grows out until the sign is obvious. We are less interested in the history of the event, than we are with the clinical sign being presented to us. Should treatment be required for focal nail bed insults, treatment is likely to be local and curative. Widespread nail bed insults may be associated with systemic diseases and if a result of local problems these may be difficult to treat.     

Nail apparatus melanoma

Nail apparatus melanoma is a relatively rare variant of melanoma with a disproportionately high mortality when compared with melanoma elsewhere. The aetiology and natural history remain poorly understood. There is no clear epidemiological association with race, skin type or sun exposure. Universally accepted clinical and histological criteria for the diagnosis of early nail apparatus melanoma have not been defined. The two cardinal clinical signs are melanonychia striata and Hutchinson's sign. These are useful but not pathognomonic of melanoma. Diagnostic delay is frequent and patients commonly have advanced disease at the time of diagnosis. Surgical excision is advocated for treatment of stage I disease; however, the most appropriate re-excision margins, including the level of amputation where required, have not been determined. Early diagnosis and excision of the tumour is the only treatment known to increase survival. Adjuvant systemic chemotherapy, isolated limb perfusion, and routine elective lymph node dissection have been used, but no survival benefit has been demonstrated.     

早期甲黑素瘤115例手术治疗方案和预后回顾分析

目的:探讨早期甲黑素瘤的手术治疗方案和预后。方法:回顾并分析第四军医大学西京皮肤医院2011年7月至2019年12月收集的115例早期甲黑素瘤的手术治疗方案及预后。结果:115例早期甲黑素瘤患者按改良的ABCDEF标准并根据如甲板改变、溃疡、结节等临床表现评估后,73例按原位甲黑素瘤扩大切除,22例按Ⅰ、Ⅱ期甲黑素瘤扩...     

Epidermotropically metastatic malignant melanoma. Differentiating malignant melanoma metastatic to the epidermis from malignant melanoma primary in the epidermis

In four instances, metastases to epidermis from primary cutaneous malignant melanomas at different sites showed histological features similar to those of cutaneous malignant melanoma primary in the epidermis. In these metastases, atypical melanocytes were present within the epidermis and in the upper part of the dermis much as in primary cutaneous malignant melanoma. Therefore, the presence of atypical melanocytes within the epidermis is not in itself an absolute criterion of malignant melanoma primary in skin. Nor does that finding absolutely deny malignant melanoma metastastic to the skin. Features that may enable histologic differentiation of epidermotropically metastatic malignant melanoma from primary cutaneous malignant melanoma are emphasized.     

Disseminated rhinosporidiosis with unusual involvement of the nail apparatus

Rhinosporidiosis is an uncommon chronic granulomatous disease caused by Rhinosporidium seeberi. It primarily affects the nasal mucosa and the nasopharynx. The disease may disseminate to the skin, larynx, trachea, genitalia, bones and even the internal organs. Although simultaneous onset of nasal and disseminated lesions has been reported, dissemination usually occurs several years after the onset of nasal lesions. We report a rare case of disseminated rhinosporidiosis involving both nares, the nasal mucosa, nasopharynx, oral cavity and oropharynx, as well as widespread cutaneous lesions over the trunk and the limbs with nail involvement. This last feature has not, to our knowledge, been previously reported.     

Clinical and histological patterns of dermatofibromas of the nail apparatus

True fibromas develop as painless slow-growing nodular tumours. They may appear in any portion of the nail apparatus. The clinical features vary according to their anatomical site. In contrast, the histological features, consisting of a dermal hypocellular reticular nodule with ill-defined demarcation, were similar in all our patients, and factor XIIIa was negative.     

The incidence and prognosis of nail apparatus melanoma. A retrospective study of 105 patients in four English regions

Our population-based study establishes epidemiological data on age-specific incidence rates, clinical presentation, Breslow microstaging, treatment and survival of nail apparatus melanoma (NAM) patients in England. Four cancer registries, covering a population of 10.6 million, recorded 105 cases of NAM during the period 1984–93. During the same decade there was a total of 7585 patients with cutaneous melanoma and NAM represents 1.4% of all cutaneous melanoma. The incidence rate of NAM in English patients is 0.1 per 100,000 of the population per annum. Amelanotic melanoma was the clinical presentation in 24 of our NAM cases. The overall prognosis is poor with an observed 5 year survival of only 51%. Patients with NAM less than 2.5 mm Breslow depth have a 5 year survival of 88% and are twice as likely to survive compared with those with tumours greater or equal to 2.5 mm in thickness ( P  < 0.05). NAM patients are best managed by a multidisciplinary team approach in a few key skin cancer centres.     

Non‐infectious inflammatory disorders of the nail apparatus

Inflammatory non‐infectious diseases of the nails are not uncommon. The nail changes may look different in the same diseases, but also very much alike in various different nail disorders depending on which particular structure of the nail apparatus is involved. Of all skin diseases, psoriasis is the one with the most frequent nail involvement. The presence of many pits allows the diagnosis to be made, but salmon spots and onycholysis are also characteristic features. Lichen planus may occur isolated on the nails or in association with lesions of the skin and adjacent mucosal membranes. Longitudinal striations and loss of the nail plate shine are the most frequent features of nail lichen planus. The more severe the alopecia areata is and the younger the patient is, the more often it affects the nail, usually with a rough surface and loss of shine. Eczemas and various autoimmune dermatoses may also affect the nails but the changes are not clinically specific.     

Concomitant traumas influence prognosis in melanomas of the nail apparatus

BACKGROUND: In nail apparatus melanomas (NAM), the role of standard melanoma prognostic factors is under discussion. The prognostic influence of traumas to the clinically apparent tumour has not been sufficiently examined. OBJECTIVES: To estimate the influence of traumas against the background of standard prognostic factors on the course of NAM. METHODS: In 33 patients (20 women, 13 men, median age 65.0 years) with NAM (median tumour thickness 3.5 mm), we retrospectively examined a detailed history of trauma to the affected extremity at first presentation. Histological or other standard prognostic factors and follow-up were studied prospectively using a standardized protocol. RESULTS: Of 33 patients, 21 had suffered injury to the clinically apparent melanoma primary between 4 and 72 months prior to definitive surgical treatment (diagnostic biopsy up to 3 months ahead of excision of the melanoma was not considered). Eight of these patients had undergone inadequate therapy procedures. In Kaplan-Meier analysis, trauma to the clinically apparent tumour and tumour thickness were found to be significant prognostic factors for recurrence-free survival, and trauma to the clinically apparent tumour, Clark level and tumour thickness were significant prognosis predictors for overall survival. In Cox's proportional hazards model, trauma to the clinically apparent tumour was found to be a significant and independent risk factor with regard to overall survival (hazard ratio 5.39; P = 0.029). An influence of trauma on the primary pathogenesis of NAM could not be confirmed. Only three patients reported trauma prior to the onset of tumour. CONCLUSIONS: From our data, trauma to the clinically apparent tumour might be a considerable risk factor in NAM. The diagnosis of NAM should be considered in lesions of the nail apparatus and further deterioration of the prognosis due to inadequate therapeutic attempts or injury to the NAM should be avoided.