Epithelioid blue nevus: a rare variant of blue nevus not always associated with the Carney complex

Epithelioid blue nevus is a rare variant of blue nevus that has been recently described in patients with Carney complex. Some of the patients with Carney complex have multiple epithelioid blue nevi and a familial history of similar lesions is often recorded. Epithelioid blue nevus consists of an intradermal melanocytic nevus composed of polygonal epithelioid cells laden with melanin. Neoplastic cells show no maturation at the base of the lesion and, in contrast with the usual stromal changes in blue nevi, epithelioid blue nevus exhibits no fibrosis of the dermis. We have studied three cases of epithelioid blue nevus in three patients with no evidence of Carney complex. The lesions were solitary and there was no family history of similar lesions. Therefore, epithelioid blue nevus is a distinctive variant of blue nevus that may also appear as a sporadic lesion and is not always associated with Carney complex.     

Compound blue nevus: a variant of blue nevus with an additional junctional dendritic component. A clinical, histopathologic, and immunohistochemical study of six cases

We studied six cases of heavily pigmented melanocytic lesions with features of blue nevi within the dermis, but with an additional junctional dendritic component. This compound variant of blue nevus is an uncommon lesion that has not been previously identified as a distinct histologic entity. Immunoperoxidase staining for S100 protein and counterstaining with azure B distinguished the presence of melanocytes among numerous melanophages within the dermis. The compound variant of blue nevus can be distinguished histologically from combined blue nevus, pigmented spindle cell nevus, malignant melanoma, and melanosis due to a regressed malignant melanoma. The six lesions were from three men and three women whose ages ranged from 11 to 51 years (mean, 31 years). Three lesions were located on the trunk, two on the extremities, and one on the head. After a mean follow-up period of 47 months (range, 38 to 58 months), there was no evidence of recurrence.     

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.     

'Tubular' epithelioid cell nevus: a new variant of Spitz's nevus

The term Spitz's nevus refers to a large spectrum of nevi composed of spindle and/or epithelioid cells. We report on a hitherto undescribed tubular variant of a dermal epithelioid nevus, characterized by aggregates composed exclusively of cuboidal cells with the prominent feature of tubular or microcystic structures, Immunohistochemically, the epithelioid cells expressed melanocytic markers (S-100, NKI/C3) lacking markers for cytokeratin or carcinoembryonic antigen. The three-dimensional analysis of the lesions by confocal laser scanning microscopy revealed the structural configuration of tubular or microcystic empty spaces bordered by cuboidal nevus cells. This rare variant of epithelioid nevus is another example for the remarkable diversity of Spitz's nevi.     

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.     

Comparative dermatology: blue nevus

There are elements in nature that may be compared to some dermatological lesions, such as the black pearl, which is very similar to a cellular blue nevus observed in the gluteus region of a 31-year-old male patient.     

皮损形态类似于脂溢性角化病的普通型蓝痣一例

蓝痣的临床表现多种多样,临床上最常见的为普通蓝痣和细胞蓝痣。此外,还有一些特殊的类型,如无色素性蓝痣、上皮样蓝痣和斑块型蓝痣等。本文报道一例皮损的临床表现类似于脂溢性角化症的普通型蓝痣。     

Malignant blue nevus arising in a giant congenital cellular blue nevus in an infant

Giant congenital blue nevus (GCBN) is rare and usually occurs on the scalp. Malignant blue nevus (MBN) is also rare and has a poor prognosis. We report a case of MBN arising in a GCBN on the back. There have been three previous reports of MBN associated with GCBN on the trunk; our case had the earliest onset of MBN arising in a GCBN.     

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.     

Cellular blue nevus with atypia (atypical cellular blue nevus): a clinicopathologic study of nine cases

Atypical cellular blue nevus (ACBN) has clinicopathologic features intermediate between typical cellular blue nevus (CBN) and the rare malignant blue nevus (MBN)/malignant melanoma (MM) arising in a CBN. Herein we report 9 cases of ACBN. The patients were caucasian (6 females and 3 males) with a mean and median age of 47/51 years. Two patients complained of recent changes and about half of these tumors were located on the buttocks or scalp, averaging 1.5 cm in diameter. Histologically, they were characterized by architectural atypia (infiltrative margin and/or asymmetry) and/or cytologic atypia (hypercellularity, nuclear pleomorphism, hyperchromasia, mitotic figures, and/or necrosis). Assessment of the expression of 3 tissue markers demonstrated rare solitary cell staining with oncogene product bcl-2, and a proliferative index of 23±19 and 39±30 cells/10 high power field with antibodies to PCNA and Mib-1, respectively. No significant differences were detected comparing the above levels of expression to a control group of 15 CBN; however, ACBNs tended to show a higher proliferative index by PCNA and Mib-1 as well as a significantly higher mitotic rate (1/10 HPF vs. 0; p=0.001). Analysis of DNA content showed DNA anetiploidy in both groups. Follow-up data on 9 of 9 patients showed 1 patient dead without disease and 8 alive without disease (mean/median follow-up 42/32 months, range 15-96 months). No patient during this follow-up time has experienced either a local recurrence or lymph node or visceral metastasis. These findings highlight the close resemblance of ACBN to the natural history of CBN. Nevertheless, many of the distinguishing histologic features of ACBN are also those of MBN. Because of these intermediate clinicopathologic features, ACBN warrant close scrutiny and long-term follow-up.     

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.     

Desmoplastic nevus: An entity distinct from spitz nevus and blue nevus

Desmoplastic (sclerotic) nevus is an infrequently reported poorly characterized benign melanocytic proliferation, with only 4 case series published to date. To better define this nevus, we examined the clinical and histologic features of 25 lesions. Desmoplastic nevus is seen in both children and adults and can be located on the face, trunk, or extremities. There is a female predominance. Clinically, it can resemble intradermal nevus, atypical nevus, melanoma, and pigmented basal cell carcinoma. These are generally small, symmetric, and well-circumscribed lesions, averaging 3.5 mm in diameter. The most distinctive features include predominantly compound growth, a zonal configuration with greater cellularity in the superficial portion of the lesion, and a mixture of melanocytic phenotypes including type A, B, and C nevus cells, ovoid and dendritic melanocytes, and Spitzoid melanocytes. A distinctive eosinophilic stroma which either resembles that of a dermatofibroma or neurofibroma is always present. Variable amounts of melanin pigment are found in both tumor cells and macrophages, but this is not a prominent feature. Mitotic activity is exceedingly rare (1 case), and pleomorphism is minimal. These lesions are distinct from typical compound nevus, Spitz nevus, epithelioid blue nevus, and desmoplastic melanoma, to which they are often compared. Strict application of these histologic features allows definitive diagnosis of desmoplastic nevus as a distinct form of a benign melanocytic nevus.     

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.