Subungual blue nevus

Junctional or compound melanocytic nevus and melanoma may involve the nail apparatus and are usually discussed in the differential diagnosis of nail pigmentation. Blue nevus has been very rarely reported in this location. We report the second clinicopathologic study of a subungual blue nevus.     

Poliosis overlying a nevus with blue nevus features

Poliosis is a localized patch of gray or white hair. Because it can be seen with a variety of disorders and drugs, a full history and exam is indicated. Additionally, it can be associated with underlying benign and malignant tumors, necessitating histological identification. We review the lesions that are reported with poliosis. In addition, we will report a case of poliosis overlying an intradermal nevus with congenital as well as blue nevus features. To the best of our knowledge, blue nevus features associated with poliosis have not been previously described.     

Plaque-type blue nevus combined with lentigo (nevus spilus)

Three cases of plaque-type blue nevus accompanied with lentigo-like changes were reported. The combination of blue nevus and lentigo (nevus spilus) is a new type of "combined nevus", but it belongs to the second type of Kawamura's atypical blue nevus. This combination is unlikely to be rare, not only in plaque-type, but also in common type blue nevus, and to be comparable with the findings of such dermal melanocytosis as nevus of Ota. Histologically, cellular blue nevus was also observed in areas of Case 1.     

Plaque-type blue nevus combined with nevus spilus and smooth muscle hyperplasia

A 31-year-old man presented with a large pigmented lesion, present since birth on his right upper aspect of his back. On examination, a speckled pigmented plaque measuring 9 × 5 cm was found on the right interscapular area. The plaque was composed of multiple dark-blue macules and papules with intervening areas of faint blue discoloration and brown patches overlapping the blue lesions ( Fig. 1 ). The lesion was slightly elevated, showing a gradual increase in height from its periphery toward its center. The lesion had enlarged as the patient grew, but there had been no change in color, size, or texture over the past few years. No other pigmentary changes were noted, and there was no family history of pigmentary disorders.

Figure 1 Open in figure viewer PowerPoint A large speckled plaque composed of an aggregation of many deep blue macules, papules and small brown patches with intervening areas of faint blue discoloration     

Systematized progradient multiple combined melanocytic and blue nevus

A 44-year-old woman was diagnosed as having unilateral multiple progradient pigmented macules and papules of the upper extremity and adjacent part of the back. Microscopically increased amounts of melanin and melanocytes in the basal layer of the epidermis in the early developmental stage of macules were seen. Combinations of blue nevus with junctional or compound nevus or with a simple proliferation of melanocytes in the epidermis were present in the papules. The question of prognosis is discussed.     

发生在斑痣上的蓝痣1例

患者男,42岁,因右足底蓝黑色结节20余年就诊。患者20余年前发现右足底蓝黑色结节,缓慢增大,无痒痛等不适。患者出生即发现右小腿淡褐色斑片,其上散在褐色斑疹,颜色渐加深,数量渐增多……     

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.     

Malignant blue nevus in Ota's nevus

A 21-year-old Caucasian woman with congenital nevus of Ota developed a subcutaneous tumor below the lacrimal sack within the area of discoloration. The tumor, located subcutaneously, has been present for 4 years. Histologically, parts of the tumor showed neuroid structures as well as those like cellular blue nevus. In one part, however, malignant transformation features could be found.     

Dermal melanocytic proliferation with features of a plaque-type blue nevus and neurocristic hamartoma

Blue nevi (BN) and neurocristic hamartomas (NCH) are pigmented lesions that originate from the aberrant development of cells derived from the neural crest. BN are composed of dermal melanocytes, whereas NCH have a broader histology and show Schwann cell differentiation as well. In addition, BN and NCH might differ in their potential to develop into a malignancy. We describe a patient with a lesion showing features of both a plaque-type BN and NCH.     

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.     

Malignant blue nevus

Malignant blue naevi with an aggressive behaviour are rare tumours. To our knowledge, this is the first reported case who has developed generalized skin melanosis and melanuria in its terminal stage.     

Malignant blue nevus

Blue nevus represents an aberrant collection of functioning benign dermal melanocytes. Its malignant degeneration is rare and is regarded as a form of malignant melanoma. We report a case of 35-year old male with this rare condition whose primary lesion over left foot ulcerated and patient later succumbed to multiple metastases.     

Trichoepithelioma associated with cellular blue nevus

BACKGROUND: Epithelial elements, such as trichoepithelioma, are occasionally associated with melanocytic nevi. OBJECTIVE: A case of trichoepithelioma in association with cellular blue nevus is reported. METHODS AND RESULTS: A solitary, pigmented nodule was removed from the scalp of a middle-aged woman. Histopathologic examination demonstrated a circumscribed cellular blue nevus within which were embedded epithelial strands and cystic structures consistent with trichoepithelioma. CONCLUSION: Trichoepitheliomas have been described in relation to common acquired nevi, but an association with a blue nevus is rare. The intimate admixture of trichoepithelioma within the nodule of a nevus supports the concept of epithelial induction by melanocytic nevi.