Plaque-type blue nevus of the oral cavity

BACKGROUND: The blue nevus of the oral cavity is a rare lesion with important differential diagnoses. The plaque-type blue nevus is an uncommon variant of the blue nevus. Because of its particular clinical appearance, it can easily be confused with satellite metastases from malignant melanoma. The diagnosis usually requires a biopsy. OBJECTIVES: To describe the clinical and histological features of a plaque-type blue nevus of the buccal mucosa in a 20-year-old white woman, to review all intraoral blue nevi and all plaque-type blue nevi reported in the literature so far and to compare the criteria of blue nevi and nevus of Ota. RESULTS: An intraoral blue nevus was described for the first time in 1959. Since then around 70 further cases have been documented. Our case is the first report of a plaque-type blue nevus of the oral cavity. CONCLUSIONS: The exceptional widespread intraoral blue nevus described herein can clinically be confused with an intraoral malignant melanoma, and it has a very similar clinical appearance as the intraoral part of nevus of Ota. Apart from the clinical resemblance, there is also some degree of histological overlap of the dermal melanocytoses. Transitional states between blue nevus and nevus of Ota may occur clinically and histologically.     

Malignant blue nevus: a report of eight cases.

Malignant blue nevus is uncommon compared to its benign counterpart and is regarded as a rare form of malignant melanoma. We report the clinical and histological findings in eight cases. Histologically, all eight specimens showed no epidermal involvement and had contained within or were adjacent to portions of blue nevus or cellular blue nevus. Proliferation of bundles of bipolar spindle shaped cells with marked cellular atypia, mitotic figures, foci of necrosis, and inflammatory cell infiltrate were noted. Two of the cases were studied by DNA flow cytometry and the populations of tumor cells were found to be diploid. Two cases have died secondary to metastasis. Although malignant blue nevi may not behave as aggressively as nodular malignant melanoma, they have definite potential to do so and therefore should be removed by wide surgical excision.     

Malignant melanoma arising in a blue nevus with features of pilar neurocristic hamartoma

A 65-year-old man presented with a history of a giant blue plaque of the parietal scalp since childhood. Biopsy revealed a cellular blue nevus. The blue nevus was observed for 10 years and thought to be unchanged until a new adjacent lesion was noted. Biopsy of the new lesion revealed metastatic malignant melanoma. A wide excision was performed of the original lesion which revealed malignant melanoma arising in a blue nevus. Areas within the blue nevus were consistent with a pilar neurocristic hamartoma, whereas other areas were consistent with a common blue nevus. Subsequent satellite metastases developed, with early metastases resembling blue nevi except for the absence of a stromal component and the presence of hyperchromatic nuclei. Later metastases were typical of metastatic melanoma. This case illustrates the uncommon evolution of malignant melanoma from a blue nevus. The histological features and relationship between melanoma, blue nevus, and pilar neurocristic hamartoma are reviewed.     

768例黑素细胞痣及类似可疑损害切除活检的回顾性分析

目的：了解黑素细胞痣诊断准确性，病理特征，去除方法及复发等问题。方法：回顾分析我院1990年－2000年诊断或疑诊黑素细胞痣的768例活检病理资料，结果：诊断为黑素细胞痣447例，疑诊为黑素细胞痣296例，黑素细胞痣恶变待排25例，共有30例（3．91％）病理诊断为恶性肿瘤，其中恶性黑素瘤6例（0．78％），基底细胞癌22例（2．86％），Bowen病2例（0．26％），结论：黑素细胞痣的诊断应予重视，在有疑问时，手术切除并做病理检查十分必要。     

Malignant blue nevus: clinicopathologic study with AgNOR measurement. Seven cases

BACKGROUND: Malignant blue nevus is a very rare tumor. Argyrophilic nucleolar organizer regions (AgNORs) have been reported to be both a diagnostic and prognostic clue in various tumors, especially if standardized using an image analysis systems. PATIENTS AND METHODS: Seven cases of malignant blue nevus were retrospectively recorded between 1974 and 1999, and their clinical and pathological features described. Using an image analysis system, AgNOR measurements were studied in all cases. These results were compared with those obtained in 10 cases of commun blue nevus, 10 cases of cellular blue nevus and 10 cases of malignant melanoma. RESULTS: The most frequent location of malignant blue nevus was the scalp. Clinically, the tumor generally consisted of a blue nodule, 2.5 cm in diameter. There was no single histopathological criterion for the diagnosis of malignant blue nevus. AgNOR measurement was significantly higher in malignant blue nevus in comparison with commun blue nevus (p<0.0004) or cellular blue nevus (p<0.012), whereas there was no difference between malignant blue naevus and malignant melanoma (p > 0.50). DISCUSSION: Our results confirm the severe prognosis of malignant blue nevus and highlight the necessity of removing all blue tumours located on the scalp. AgNOR measurement using an image analysis system appears to be a useful tool for the diagnosis of malignant blue nevus, but further studies remain necessary.     

Melanoma within naevus spilus: 5 cases

BACKGROUND: Nevus spilus is defined as café-au-lait macules with dark maculopapular speckles. Histologically, it has the aspect of lentigo associated with nevocellular nevus. There are 3 types of nevus spilus: small or medium-sized (<20 cm), giant and zosteriform. Malignant transformation of nevus spilus is rare. PATIENTS AND METHODS: We analyzed the cases of 5 patients presenting melanoma within nevus spilus as well as 20 published cases. The evaluation criteria were: for nevus spilus: size, type, topography, age of onset and presence of dysplastic nevi within the nevus spilus; for melanoma: clinical aspect, histological type, thickness, level and age at diagnosis. The presence of other risk factors for melanoma was noted. RESULTS: The 14 women and 11 men had a mean age of 49 years at melanoma diagnosis. Type of nevus spilus was: small or medium-sized (15 cases), zosteriform (6 cases) and giant (4 cases). Only 3 nevi spili were<4 cm in diameter. Nevus spilus was present since birth (11 cases), childhood (7 cases), after the age of 20 years (3 cases) and was unspecified in 4 cases. Three of our five patients had other risk factors for melanoma. Two patients were presenting 2 melanomas within nevus spilus. The histological type of melanoma was not specified in 8 cases but SSM was the most common type (13 cases). Median Breslow thickness was 1.25 mm (0.27 to 8 mm) for the 19 cases in which it was specified. CONCLUSION: The following criteria appeared to be associated with risk of developing melanoma in nevus spilus patients: nevus spilus present since birth, nevus spilus over 4 cm in diameter, and giant or zosteriform nevus spilus. Development of melanoma within nevus spilus is a rare event. Consequently, guidelines for follow-up of nevus spilus cannot be defined. However, follow-up is recommended, and in particular, self-examination.     

Fluorescence in situ hybridization for distinguishing cellular blue nevi from blue nevus-like melanoma

Background: Blue nevus‐like melanomas are melanomas that arise in association with blue nevi or closely simulate the histopathologic appearance of a blue nevus, usually a cellular blue nevus (CBN). Although the majority of CBN can be readily distinguished from blue nevus‐like melanoma by conventional microscopy, there are a subset of cases where this distinction may be exceedingly difficult or impossible. Methods: In this study, we evaluated the ability of a fluorescence in situ hybridization (FISH) assay targeting 6p25 (RREB1), 6q23 (MYB), 11q13 (CCND1) and the centromere of chromosome 6 (Cep6) to distinguish between CBN and blue nevus‐like melanoma. We identified five cases of blue nevus‐like melanoma and 12 cases of CBN. Results: The FISH assay was performed with 100% sensitivity and 100% specificity. Three of five cases met the 6p25/Cep6 criteria, all five met the 6p25 gain criteria and three of five met the 6q23/Cep6 loss criteria. None of the cases met criteria for gains in 11q13. None of the 12 CBN met any criteria for melanoma. Conclusions: A combined analysis of clinical aspects, histopathologic changes and FISH analysis could potentially contribute significantly to the ability of pathologists to discriminate between blue nevus‐like melanoma and blue nevi in challenging cases. Gammon B, Beilfuss B, Guitart J, Busam KJ, Gerami P. Fluorescence in situ hybridization for distinguishing cellular blue nevi from blue nevus‐like melanoma.     

Malignant blue nevus. Case report and literature review

A well-documented case of malignant blue nevus is presented, along with an in-depth review of the literature. Malignant blue nevus is a rare form of malignant melanoma. A cellular blue nevus is the precursor lesion. The scalp is the most common site. The tumor often presents clinically as a progressively enlarging or multinodular blue-black lesion. The histologic pattern is fascicular dense collections of pigmented, pleomorphic spindle cells. Because of marked regional histologic variation within a malignant blue nevus, however, sampling error can cause delay in recognition of malignancy. A high clinical index of suspicion and appropriate biopsy technique are necessary to reach an early diagnosis. The most common site of metastasis of a malignant blue nevus is the lymph node. The phenomenon of benign lymph node nevus cell metastasis, which may occur with benign blue nevi, must be differentiated from a true malignant metastasis of a malignant blue nevus.     

Desmoplastic melanocytic nevi with lymphocytic aggregates

Desmoplastic melanocytic nevi can be difficult to distinguish from desmoplastic melanoma. The presence of lymphocytic aggregates in association with a sclerosing melanocytic proliferation is commonly regarded as a feature in support of a diagnosis of desmoplastic melanoma. However, the finding is not specific for melanoma. Herein we report six cases of sclerosing melanocytic nevi with associated lymphocytic aggregates. They occurred in five women and one man, ranging in age from 11 to 61 years. Three lesions were sclerosing Spitz nevi; one was an amelanotic sclerosing blue nevus, one an acquired intradermal sclerosing nevus, and one was a congenital compound melanocytic nevus with sclerosis of its dermal component. The lesions were interpreted as benign, i.e. melanocytic nevi, because of their histopathologic attributes (symmetric silhouette, benign cytologic features) and results from immunohistochemical studies (all lesions strongly expressed Melan-A and p16) and fluorescence in situ hybridization (FISH). Three lesions tested by FISH lacked copy number changes of 11p, 6q or 6p. None of the lesions recurred. The cases highlight that contextual information is essential for the diagnosis of desmoplastic melanoma and sclerosing nevus. The presence of lymphocytic aggregates per se does not prove that a sclerosing melanocytic proliferation is malignant.     

Focal melanocytic atypia in dysplastic nevus cell nevi. Results of a serial section study

Dysplastic nevi were diagnosed according to the ABCDE rule for recognition of early melanomas in 11 patients with familial dysplastic nevus syndrome (DNS) and in 39 patients with the sporadic variant of DNS. All these 50 patients exhibited multiple dysplastic nevi. On routine histological examination melanocytic atypia confirming the histological diagnosis of dysplastic nevus was found only in 12/50 cases. However, when cut consecutively dysplastic nevi with melanocytic atypia were diagnosed in 17 further cases (34%). In most cases (72.4%) only a mild degree of atypia (grade I) was found. Dysplastic nevi with severe melanocytic atypia (grades II-III) were found in all groups of sporadic and familial variants of DNS (with and without melanoma). To improve the prognostic value of the histological examination in dysplastic nevi significantly it must be of interest to add the degree of melanocytic atypia. With increasing degree of melanocytic atypia also the typical histological feature of dysplastic nevi become more significant. Since such atypia in dysplastic nevi is not necessarily sited in the centre of the lesion and since in most cases melanocytic atypia occurs focally, we believe that histological examination of dysplastic nevi must be undertaken by step section. Lesions suspected of being dysplastic nevi must be excised with margins of at least 2-5 mm for a correct histological diagnosis.     

Amelanotic blue nevus: a variant of blue nevus.

Blue nevi are typically heavily melanized. We report a variant of blue nevus that is minimally pigmented. Of the 1,358 blue nevi seen in our laboratory during the last 6 years, 38 (2.7%) were selected that had scant or absent melanin. We refer to these blue nevi as the amelanotic type. Approximately half of the cases in clinical diagnosis were nevus of some type, whereas other differential diagnoses were basal cell carcinoma, dermatofibroma, and lesion. Histologically all specimens were characterized by the spindle-shaped cells seen in blue nevi, but with very little or no obvious melanin. Some lesions were markedly cellular, resembling the features of cellular blue nevus. No hemosiderin was identified on Perls' stain, whereas Fontana-Masson stain was variably positive. Usually there was fibrous stroma. In most cases, the histologic differential diagnosis was dermatofibroma. Other histologic differential diagnoses included amelanotic and/or spindle cell melanoma, dermal Spitz nevus, neurofibroma, and scar. There was no pleomorphism or increased mitotic activity. Evidence of epidermal melanocytic hyperplasia was seen in two cases. Furthermore, the lesions had been present for many years without evidence of recent change. Immunohistochemistry showed all cases to be strongly positive with anti Mel-5 antibody, but only weakly positive or negative with anti S-100 and HMB-45 antibodies. We would like dermatologists and pathologists to be aware of this unusual and uncommon entity.     

Acral Lentiginous Nevus

In non-Caucasians, malignant melanoma most frequently affects the sole of the foot. To improve the prognosis in such patients, accurate diagnosis of early lesions is extremely important, and, to avoid potentially mutilating surgery, it is equally important to identify benign acral nevus. Clemente and colleagues recently proposed a new clinicopathological entity, designated acral lentiginous nevus (ALN) of the plantar skin. The clinical and histopathological characteristics of these nevi enable clinicians to distinguish them from ordinary nevi and melanoma. We report four additional cases of ALN, which can be classified as belonging to the “pseudomelanoma” group.     

Eruptive multiple blue nevi of the penis: a clinical dermoscopic pathologic case study

Multiple blue nevi have rarely been reported, and the majority of the lesions are located on the trunk and lower extremities. The blue nevus is a rare lesion on genital mucosa and may cause confusion in differential diagnosis with other pigmented lesions such as genital melanocytic macules, lentigo simplex, and malignant melanoma. Here, we describe an unusual patient who presented with a sudden onset in adulthood of multiple blue nevi on the glans penis. The epiluminescence examination revealed a substantially homogenous bluish pigmentation, which led us to favor a diagnosis of blue nevus, whereas not entirely excluding the possibility of a regressing melanoma or a metastatic melanoma. Because of the well-known diagnostic value of the blue hue in the diagnosis of malignancy by dermoscopy, a careful examination of these lesions should be made in order to minimize any risk of misclassification with melanoma.     

Histologic features of melanocytic nevi seen in association with mycosis fungoides

BACKGROUND: Many different tumors have been reported to occur simultaneously as collision lesions. To date, no such events have been reported between mycosis fungoides (MFs) and melanocytic neoplasms. METHODS: Two cases are presented in which patches of MF were superimposed on melanocytic nevi. In addition, 967 biopsies of MF from 411 patients were identified in an 8-year retrospective database search. Patient pathology history summaries were reviewed to identify inflamed nevi, atypical nevi, and melanoma submitted for histologic evaluation from this population. RESULTS: The occurrence of MF in a congenital nevus was associated with a halo phenomenon restricted to the affected region of the nevus in one patient. In the other patient, nests of two morphologies (lymphocytic and melanocytic) in the same biopsy presented a potentially confusing histologic picture. No other cases of MF superimposed on a nevus were identified in 967 biopsies from 411 patients with a histological diagnosis of MF seen over the past 8 years. In this population, 57 biopsies of melanocytic lesions were identified from 28 patients, including three atypical nevi and three melanomas. CONCLUSIONS: The presence of MF superimposed on a nevus is rare and may lead to confounding histologic features or the development of a halo nevus phenomenon.     

Clinical diagnosis of dysplastic melanocytic nevi: A clinicopathologic correlation

A prospective, community practice-based, clinicopathologic correlation was undertaken in 165 melanocytic nevi excised from a group of forty-three patients, each patient having previously had at least one clinically suspected and histologically confirmed dysplastic melanocytic nevus. Eighty-two percent of seventy-two lesions with histologic evidence of mild dysplasia had been diagnosed correctly as such clinically. The accuracy of clinical diagnosis of moderate dysplasia was low (20%); however, all cases of severe dysplasia with or without in situ melanoma were diagnosed correctly. In 75% of all cases in which dysplasia of any degree was diagnosed clinically, histologic evidence of dysplasia was found. In order to investigate further the clinical features of these nevi, 175 color enlargements of histologically confirmed dysplastic melanocytic nevi were examined. The following clinical features were found to be most common: ill-defined border (90%), irregularly distributed pigmentation (84%), maximum diameter greater than 5.0 mm (72%), erythema (64%), and accentuated skin markings (63%). Increasing darkness and confluence of pigmentation in these dysplastic melanocytic nevi correlated with increasing severity of dysplasia. We conclude that careful clinical examination of individual melanocytic nevi will separate severe dysplasia with or without in situ melanoma from low-grade (mild or moderate) dysplasia in a high percentage of nevi from patients with the dysplastic nevus syndrome. Clinical examination will yield a diagnosis of dysplasia in approximately 75% of nevi from such patients in whom histologic evidence of dysplasia is present. Clinical examination constitutes a practical and sufficiently reliable method for the assessment of melanocytic nevi in patients with the dysplastic nevus syndrome.     

A Malignant Melanoma Associated with a Blue Nevus of the Lip

Blue nevi are characterized by a collection of pigment-producing melanocytes in the dermis. These lesions clinically present as well demarcated cerulean-blue or bluish black colored papules or plaques that usually measure less than 1 cm in diameter. They are typically found on the dorsal surface of the hands and feet or in the head and neck region; however, they are rarely found in the oral cavity. These lesions are usually benign and stable over time. However, malignant melanomas developing in or associated with a blue nevus (which is also called malignant blue nevus) have been only rarely reported. A malignant blue nevus might develop in a common blue or cellular blue nevus, a giant congenital nevus or in a nevus of Ota, or it may be malignant from the start. Malignant blue nevi most commonly are found on the scalp. A malignant blue nevus of the lip has not been previously reported in the medical literature. We report here on a patient with a malignant melanoma associated with a blue nevus of the lip. The malignant melanoma was presumed to have developed from a blue nevus that was present on the upper lip of a 50-year-old male.     

Homogeneous blue pattern in an acral congenital melanocytic nevus

Dermoscopy in acquired acral melanocytic nevi has been widely studied. This is in contrast with the little information about the dermoscopic characteristics in congenital acral melanocytic nevi. We report a 46-year-old man who was referred due to a lesion on his right sole present since childhood corresponding to an acral congenital nevus. Dermoscopy showed a homogeneous blue pattern not previously described in acral benign tumors. The homogeneous blue pattern has previously been associated with blue nevus and skin metastasis of melanoma. The recognition of this pattern in benign acral congenital nevi is relevant in the clinical decision making concerning acral tumors.     

胰岛素样生长因子ⅡmRNA结合蛋白3在恶性黑素瘤及良性痣中的表达

目的 探讨胰岛素样生长因子Ⅱ mRNA结合蛋白3(IMP3)在良性痣及黑素瘤组织中的表达,及其在恶性黑素瘤进展及诊断中的作用.方法 用IMP3抗体对28例恶性黑素瘤、8例Spitz痣、6例发育不良性痣和25例良性痣患者的标本组织进行免疫组化研究.结果 28例恶性黑素瘤组织标本中23例IMP3阳性,8例Spitz痣中4例阳性,6例发育不良性痣中2例阳性,25例良性痣均不表达.IMP3在黑素瘤中的表达明显高于Spitz痣及发育不良性痣(P<0.05),侵袭性黑素瘤表达明显高于原位黑素瘤(P<0.01).结论 IMP3可能是良性痣发展至恶性黑素瘤的一个生物学标志,在鉴别黑素瘤和良性痣之间存在一定的价值.     

Blue nevi: a case report and review of the literature

Blue nevi can present clinically as blue, gray, brown, or black solitary nodules or plaques on the skin. Histologically, they represent collections of melanocytes and melanophages in the dermis. We present a case of a cellular blue nevus in a 55-year-old white man that presented as an enlarging blue-gray nodule on the right dorsal foot. These cases can be challenging both clinically and histologically because malignant melanoma or malignant transformation of a blue nevus should be considered. We review the various types of blue nevi and the literature.     

Small congenital nevi associated with melanoma: case reports and considerations

Melanocytic nevi, both congenital and acquired, are considered to be precursors of melanomas. Data about the malignant potential of these nevi are conflicting, particularly with reference to the nevus of the smallest size. Patients with preexisting melanocytic nevi (both congenital and acquired) have risks of developing melanoma that differ from those of subjects without them. The purpose of this study was to verify the presence of melanoma in preexisting nevi both congenital (congenital nevus associated melanoma) (CNAM) and acquired (ANAM). In particular, we investigated melanomas associated with small congenital nevi (SCN). A cohort of 190 patients with primary melanomas was studied. Congenital nevi were called "small" (SCN) when their diameters were less than 1.5 cm. Epiluminescence microscopy (ELM) was performed to further improve the clinical diagnosis and to observe the more subtle changes in the preexisting nevi. Forty of the 190 cases of melanoma were associated with preexisting nevi; of these, 15 had congenital features with a CNAM largest diameter of 1.5 cm. These 15 cases were melanomas of the superficial type with a mean tumor thickness lower than that of ANAM (0.33 vs 1.50). There were no differences between the locations of CNAM and other melanomas. Male patients were significantly more affected. ELM microscopy permitted us to detect the early malignant changes in nevi and thus to improve our diagnosis. A high percentage of small congenital nevi were found to be associated with melanomas. They may be considered as melanomas precursors. Because of their large number and frequency, prophylactic removal of all SCN is not feasible. However, they should be removed as soon as possible when clinical or ELM changes are observed.