Subungual Pigmented Nevus: Evaluation of DNA Ploidy in Six Cases

The discrimination between subungual pigmented nevus and subungual melanoma in situ is still a clinical problem. We measured DNA ploidy in six cases of subungual melanotic lesions which exhibited the features of subungual pigmented nevus or lentigo simplex histologically. Five cases presented a diploid pattern with or without a slight increase of hyperdiploid cells. One case presented a polyploid pattern; it also exhibited histologically abnormal melanocytes with large nuclei and pigment-filled elongated dendrites. The DNA ploidy pattern and histologic features suggest that the lesion of this latter case contains abnormal melanocytes which probably have the potential to undergo a malignant transformation into a subungual melanoma. DNA ploidy analysis, therefore, is likely to provide information for evaluating the biologic behavior of subungual melanotic lesions.     

A case of nodular subungual melanoma without Hutchinson's nail sign

An early and accurate diagnosis is critical for the optimal management of subungual melanoma; the absence of Hutchinson's nail sign makes an accurate diagnosis extremely difficult. Previous publications show that most subungual melanomas have Hutchinson's nail sign. In this report, we present a rare case of a subungual melanoma without Hutchinson's nail sign and discuss the importance of cautious evaluations of Hutchinson's nail sign by dermoscopy.     

Two cases of subungual melanoma in situ

Melanonychia, which is characterized by brown or black pigmentation within the nail plate, includes heterogeneous conditions such as pigmented nevus, subungual melanoma and lentigo. We treated two cases of subungual melanoma in situ. One case was a 58‐year‐old woman who suffered from a malignant melanoma in situ of the left third fingernail, who had also suffered from melanonychia of the fingers for more than 30 years. She had a past history of carcinoma of the uterine cervix. The other patient was a 42‐year‐old man, who suffered from a malignant melanoma in situ of the right fifth fingernail. He had a past history of carcinoma of the stomach for which he had undergone surgery 2 years earlier. Both cases were accompanied by Hutchinson's sign on the fingertip skin, and the presence of this sign led to the correct diagnosis of subungual melanoma in situ. Judging from previously reported cases, it is unlikely that patients with malignant melanoma have an increased risk of carcinoma of the uterine cervix or of the stomach.     

Subungual malignant melanoma with cartilaginous differentiation

A case of subungual malignant melanoma with cartilaginous differentiation is presented and the phenomenon of sarcomatoid differentiation in malignant melanoma reviewed. Osseous and/or cartilaginous (osteocartilaginous) differentiation of malignant melanoma is rare. Only 14 cases have previously been reported. This small number of cases and the subject of this Case Report have several features in common, including acral (particularly subungual) location, high Breslow thickness, presence of a lentiginous radial growth phase component, and predominance of epithelioid melanocytes with amelanotic cytoplasm. Melanoma with osteocartilaginous differentiation may therefore represent a subgroup of melanoma with distinctive clinical and pathologic features. Further study is required to establish whether any unique molecular or genetic features are also present.     

Two kinds of Hutchinson's sign, benign and malignant

We examined 6 subungual melanomas in situ and 18 melanocytic nevi and compared pigmentation of the nail plates and hyponychium with the use of a dermatoscope. Hutchinson's sign on the hyponychium was not always evidence of subungual melanoma because it can be seen in both diseases. However, there was a wide difference in their dermatoscopic features. We believe that observation of pigmentation on the hyponychium with the use of a dermatoscope contributes to the precise diagnosis of subungual melanoma.     

Dermoscopy of subungual haemorrhage: its usefulness in differential diagnosis from nail‐unit melanoma

Background Subungual haemorrhages are characterized by well‐circumscribed dots or blotches with a red to red–black pigmentation, but some cases can be difficult to distinguish from subungual melanoma by the naked eye alone. Dermoscopy has proven to be a useful, noninvasive tool in the diagnosis of pigmented lesions in the nail; however, few dermoscopic studies of subungual haemorrhages have been reported. Objectives To investigate characteristic dermoscopic patterns of subungual haemorrhages, and to find distinctive features that can differentiate them from nail‐unit melanomas. Methods Patients with a confirmed diagnosis of either subungual haemorrhage or nail‐unit melanoma at a tertiary university hospital were included in the study. Clinical features and dermoscopic patterns were evaluated. Results Sixty‐four patients with a total of 90 lesions of subungual haemorrhage were enrolled in the study. The majority of cases (84%) showed combinations of more than one colour, while 16% had only one colour. The most common colour of the subungual haemorrhages was purple–black, in 37% of cases. A homogeneous pattern was observed in 92% of cases, globular patterns in 42% and streaks in 39%. Peripheral fading and periungual haemorrhages were found in 54% and 22% of cases, respectively. Destruction or dystrophy of the nail plate was observed in 16% of cases. In the 16 cases of nail‐unit melanomas, Hutchinson sign, longitudinal irregular bands or lines, triangular shape of bands, vascular pattern, and ulcerations were found in 100%, 81%, 25%, 6% and 81% of cases, respectively. In contrast, these features were not found in subungual haemorrhages. Conclusions Dermoscopy provides valuable information for the diagnosis of subungual haemorrhage and aids in the differential diagnosis from nail‐unit melanoma.     

The rare occurrence of three subungual melanomas in one patient

Subungual melanoma commonly presents with solitary longitudinal melanonychia. Herein, we report the case of a patient with subungual melanoma who developed involvement of three digits by three independent primary melanomas. A 98-year-old male patient presented with a two-year history of longitudinal melanonychia on three different fingernails. Histopathologically, all three lesions were proved to be melanoma. To our knowledge, this is the first reported case in which three subungual melanomas developed in one patient. Our case indicates that that not all examples of multiple longitudinal melanonychia represent benign lesions.     

Is subungual melanoma related to trauma?

Subungual melanomas represent approximately 20% in dark-skinned and oriental populations compared to about 2% of cutaneous melanomas in white populations. UV exposure seems to be an important risk factor for cutaneous melanoma. However, UV radiation is unlikely to penetrate the nail plate. Another pathogenetic factor of subungual melanoma will be discussed. 406 subungual melanomas of the hands (n = 240) and feet (n = 166) of 74 patients from the melanoma registry of the Department of Dermatology, University of Tübingen, and of 332 patients from the literature were evaluated. The hypothesis of a uniform distribution of the occurrence of subungual melanoma on the fingers and toes had to be rejected (p < 0.001 using the chi(2)(4,0.95) test).There was a considerable predominance of subungual melanoma localized on the thumb (58% of all fingers) and the hallux (86% of all toes). Many patients report direct trauma related to the onset of subungual melanoma. This might be explained by coincidence, increased attention to a dark area under the nail, traumatic bleeding of a subclinical subungual melanoma or mutation of melanocytes during trauma-induced proliferation. Squamous cell carcinoma is known to occur in sites of chronic trauma. Trauma could be an etiologic factor in subungual melanoma as well.     

甲下无色素性黑素瘤远端淋巴结转移

报告1例甲下无色素性黑素瘤远端淋巴结转移.患者女,28岁.左拇指甲下淡红色肿物1年半.结合病史、皮损特点、实验室检查、皮损及肿大淋巴结组织病理改变、免疫组化检查结果,确诊为该病.     

Cartilaginous melanoma: case report and review of the literature

Malignant melanoma can present a variety of histopathological patterns. Cartilaginous change in the absence of osteogenic differentiation is extremely rare in malignant melanoma, being among the least frequent of the wide range of melanoma histologic patterns. We report a case of a 47-year-old woman with a subungual nodule on her right great toe for many years. Histopathological examination of the lesion led to a diagnosis of malignant melanoma with cartilaginous differentiation devoid of concomitant osseous areas. It would appear that this unusual form of melanoma has a predilection for acral location, particularly the subungual region. Malignant melanoma with chondroid stroma should therefore be considered in the differential diagnosis of cartilaginous lesions of the toes and fingers. Careful examination of the overlying epidermis and identification of an in situ component of melanoma may be necessary in order to establish the correct diagnosis.     

Subungual amelanotic malignant melanoma

A 52-year-old man with subungual amelanotic malignant melanoma was reported. He had a dome-shaped tumor on his right thumb nail bed without any involvement. Clinically, we considered various diseases including amelanotic malignant melanoma, squamous cell carcinoma, granuloma pyogenicum, and other granulomas. Histological features of the skin biopsy taken during the first visit suggested squamous cell carcinoma. We still considered the possibility of amelanotic malignant melanoma, however, and the specimens taken during the radical operation were examined histologically and histochemically and a diagnosis of subungual amelanotic malignant melanoma was determined.     

SUBUNGUAL MALIGNANT MELANOMA: A DISEASE ENTITY SEPARATE FROM OTHER FORMS OF CUTANEOUS MELANOMA

The characteristics and results of treatment of 30 patients with subungual malignant melanoma treated at the Sydney Melanoma Unit were studied. It was found that in several major respects subungual melanoma differed from other forms of cutaneous melanoma. Patients with subungual melanoma were considerably older than those with either superficial spreading or nodular melanoma and there was a preponderance of men with subungual melanoma of the upper extremity. Independent prognostic factors (such as tumour thickness) which are important in determining survival in patients with superficial spreading or nodular melanoma, had little consequence in patients with subungual melanoma. Despite the fact that the vast majority of subungual melanomas were very thick and ulcerated due to the delay in correctly diagnosing the disease clinically, overall survival rate was reasonably good, providing patients had an amputation of the entire digit together with either a prophylactic or therapeutic lymph node dissection. These findings indicate that subungual melanoma is a disease entity separate from other forms of cutaneous melanoma and that radical surgery is essential in all subungual melanoma patients.     

A Rare Case of Subungual Melanoma

A 51-year-old male presented with blackish discoloration of nails of 10 months duration. Examination revealed black dystrophic left thumb finger nail. Detailed examination showed a mass under the dystrophic nail. Hutchinson sign was positive. Histopathology revealed characteristic features of melanoma. A detailed evaluation revealed no features of local or distant metastasis. The entire lesion was then removed surgically along with disarticulation at the interphalangeal joint. Resection-free margin was confirmed. This case is being reported for the rare occurrence of subungual melanoma in the Indian population and also for presentation with a long history of lesion with no evidence of metastasis.     

Osteoid and bone formation in desmoplastic malignant melanoma

A 77-year-old man presented a recurrent subungual malignant melanoma with desmoplastic features in which heterotopic bone had developed. Histological, histochemical and immunohistochemical findings confirmed the diagnosis of malignant melanoma. Electron microscopic findings suggest that desmoplasia is the result of fibroblastic differentiation of spindle melanoma cells.     

Painful growth on right index finger. Subungual glomus tumor

Glomus tumors (GT) are rare, soft-tissue tumors commonly found on the extremities. Because these tumors occur most often in the subungual region, they can be confused with other subungual pathologies including melanoma. Subungual GTs have a unique presentation and history but biopsy is diagnostic. Various imaging techniques are useful in diagnosis and management. We describe a classical case of subungual GT and discuss its presentation, diagnosis, management, as well as "atypical" or "malignant" variants.     

266例黑甲性皮损的皮肤镜特点分析

【摘要】 目的 比较临床常见黑甲性疾病的皮肤镜表现及特点。方法 回顾性分析2016年1月至2020年7月在第四军医大学西京皮肤医院行皮肤镜检查的4种常见黑甲皮损皮肤镜图像特征。结果 共纳入266例黑甲性皮损,其中甲黑素瘤64例（24.1%）,甲母痣52例（19.5%）,甲下出血89例（33.5%）,甲真菌病61例（22.9%）。甲黑素瘤及甲母痣多发于指甲,甲黑素瘤发生于拇指甲的比例高（62.8%）,甲母痣则更多发生于2 ~ 5指甲（73.9%）;甲下出血及甲真菌病多发于趾甲,其中甲下出血51例（57.3%）,甲真菌病46例（75.4%）。甲黑素瘤好发于40岁以上患者（49例,76.8%）,其余3组疾病则多见于40岁以下患者。甲黑素瘤皮肤镜表现主要为纵向规则条带（35例,54.7%）或不规则条带（25例,39.0%）,87.5%的病例色素带宽度大于3 mm, 36例（56.3%）Hutchinson征阳性, 15例（23.4%）破溃,颜色以黑褐色为主;甲母痣表现为单一规则色素带结构（52例,100%）,36例（69.2%）色素带宽度小于3 mm,26例（50%）Hutchinson征阳性,无破溃病例;甲下出血表现为弥漫性斑疹（74例,83.1%）,85例（95.5%）见暗红色或黑色出血小球结构;黑甲性甲真菌病表现为黑褐色纵向不规则条带（54例,88.5%）。结论 皮肤镜下,甲黑素瘤可表现为纵向规则条带,条带宽幅大于3 mm,甲母痣多表现为纵向规则条带,甲下出血表现为弥漫性污斑,甲真菌病可表现为纵行不规则条带。皮肤镜可用于鉴别黑甲性皮损,为甲黑素瘤辅助诊断提供依据。     

Acral lentiginous melanoma mimicking benign disease: the Emory experience

BACKGROUND: Plantar and subungual melanoma exhibits a higher misdiagnosis rate relative to other anatomic sites. Misdiagnosis and delay in diagnosis are statistically associated with poorer patient outcome. Awareness of atypical presentations of acral melanoma may, thus, be important to decrease misdiagnosis rates and improve patient outcome. METHODS: We conducted a retrospective case review of plantar or lower-extremity subungual melanoma performed at Winship Cancer Center, a tertiary care, referral center affiliated with Emory University, between 1985 and 2001. RESULTS: A total of 53 cases of plantar or lower-extremity subungual melanoma were identified. Of 53 cases with a final diagnosis of melanoma, 18 were initially misdiagnosed. Misdiagnoses included wart, callous, fungal disorder, foreign body, crusty lesion, sweat gland condition, blister, nonhealing wound, mole, keratoacanthoma, subungual hematoma, onychomycosis, ingrown toenail, and defective/infected toenail. Of the 18 misdiagnosed cases, 9 were clinically amelanotic. CONCLUSION: Awareness that amelanotic variants of acral melanoma may assume the morphology of benign hyperkeratotic dermatoses may increase the rate of correct diagnosis and improve patient outcome.     

Lesiones melanocíticas subungueales en la edad pediátrica

The study of subungual melanocytic lesions can present challenges because of the clinical and histologic characteristics of the nail unit and the difficulty of performing nail biopsies and processing specimens. These lesions can be even more challenging in children due to differences in clinical and epidemiological profiles between the adult and pediatric populations. Many of the clinical features of subungual melanocytic lesions that would raise alarm in an adult do not have the same implications in children. Consensus is also lacking on when a nail biopsy is needed to rule out malignancy in the pediatric setting. In view of these considerations and the rarity of subungual melanoma in childhood, the recommended approach in most cases is a watch-and-wait strategy. Subungual melanocytic lesions in children may also show atypical histopathologic features that are not necessarily associated with aggressive behavior. Subungual melanoma is very rare in childhood, with just 21 cases described to date. None of the patients developed visceral metastasis or died as a result and the diagnosis was controversial in many of the cases. Considering the above and the significantly higher frequency and particular characteristics of longitudinal melanonychia with a benign etiology in children, subungual melanocytic lesions should be managed differently in this setting than in adults. In most cases, a watch-and-wait approach is the most appropriate strategy.     

[Translated article] Subungual Melanocytic Lesions in Pediatric Patients

The study of subungual melanocytic lesions can present challenges because of the clinical and histologic characteristics of the nail unit and the difficulty of performing nail biopsies and processing specimens. These lesions can be even more challenging in children due to differences in clinical and epidemiological profiles between the adult and pediatric populations. Many of the clinical features of subungual melanocytic lesions that would raise alarm in an adult do not have the same implications in children. Consensus is also lacking on when a nail biopsy is needed to rule out malignancy in the pediatric setting. In view of these considerations and the rarity of subungual melanoma in childhood, the recommended approach in most cases is a watch-and-wait strategy. Subungual melanocytic lesions in children may also show atypical histopathologic features that are not necessarily associated with aggressive behavior. Subungual melanoma is very rare in childhood, with just 21 cases described to date. None of the patients developed visceral metastasis or died as a result and the diagnosis was controversial in many of the cases. Considering the above and the significantly higher frequency and particular characteristics of longitudinal melanonychia with a benign etiology in children, subungual melanocytic lesions should be managed differently in this setting than in adults. In most cases, a watch-and-wait approach is the most appropriate strategy.     

Epidemiology and prognosis of subungual melanoma in 34 Japanese patients

The incidence of malignant melanoma is much lower in the Japanese than in Caucasians. However, amongst the various types of malignant melanoma, the subungual and periungual sites are commonly found in the Japanese. One hundred and fifty-one cases of cutaneous malignant melanoma were seen over a 25-year period at our hospital. We found that. In 34 patients (23%). the subungual region was involved, a high frequency for one institution. We have analysed these patients and looked at their treatment. The finger nails were affected in 21 cases (62%) and the toe nails in 1 3 cases (38%). The thumb nails or great toe nails were at tecled in 25 of the 34 patients (73%). In 25 patients, histopathological features of acral lentiginous melanoma were found, with four cases of superficial spreading melanoma and five of nodular amelanotic melanoma. Of the latter group, four mimicked tibrous histiocytic tumour, and one was a desmoplastic malignant melanoma. I he proportion of patients presenting with stage III disease decreased after 1982. with a corresponding increase in patients whose tumour thickness was less than 4 mm (stage II). Concurrently, the prognosis for subungual malignant melanoma improved. The 5-year survival rate in each of the periods 1969–82 and 1981—93 was 5 3 and 87%. respectively. This is similar to that found in plantar malignant melanoma and is fell to be due to a greater public awareness of the condition and to the introduction of effective chemotherapy (the DTIC-AC nitro surear vincristine (OAV) regimen). Although the frequency of malignant melanoma is rather low in the Japanese, our data indicate that there is a high incidence of subungual malignant melanoma. Public awareness of the early stage of malignant melanoma seems to have improved prognosis.