1/16. Cerebriform intradermal nevus: a case of scalp expansion on the galea.We report here a 7-year-old Japanese girl with cerebriform intradermal nevus (CIN). By placement of expanders on the galea, her scalp was expanded more easily with less discomfort than is expected when the expanders are placed under the galea. An immunohistochemical study on the expression of proliferating cell nuclear antigen suggested higher proliferative activity of nevus cells from the CIN lesion than that of cells from congenital or acquired intradermal nevi. The high proliferative activity appeared to be associated with a growth spurt of the lesion.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/16. rosette formation within a proliferative nodule of an atypical combined melanocytic nevus in an adult.rosette formation is a feature that has not been described as occurring in melanocytic neoplasms. We present such a unique case. A 59-year-old man presented with an asymptomatic, soft, hairy 3.0 x 2.0-cm pigmented lesion that had been present for many years in the right external ear, extending from the conchal bowl onto the antitragus area. Examination of histologic sections showed a proliferation of nonatypical and heavily pigmented melanocytes in the superficial dermis and around deep adnexal structures, characteristic of a congenital nevus. In other areas, pigmented spindled and dendritic cells infiltrated thickened collagen bundles in a pattern of a blue nevus. A nodular proliferation of epithelioid melanocytes was seen within the deep dermis and subcutaneous tissue. The periphery of the nodule merged with the surrounding nevus cells. Neoplastic cells with nuclear atypia, melanin pigment, pseudonuclear inclusions, and balloon cell change were present. In addition, there was rosette formation by the tumor cells, with a central aggregate of coarse cell processes. Neuroid cords were also noted. No prominent mitotic figures, necrosis, or significant inflammatory infiltrate were noted. The neoplastic cells were positive for S-100 protein, Mart-1, tyrosinase, neuron-specific enolase, and vimentin. HMB-45 and Ki-67 (MIB-1) labeled only rare neoplastic cells within the proliferative nodule. The tumor cells were negative for synaptophysin, protein gene product 9.5, CD57, epithelial membrane antigen, CD31, and CD34. The central cell processes of the rosettes were negative for trichome, type IV collagen, neurofilament protein, glial fibrillary acidic protein, and tyrosine hydroxylase. We also retrospectively examined 78 congenital nevi of 65 pediatric patients at our institution. rosette formation was not seen in any of these cases.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/16. Pseudo-tumoral proliferative nodule in a giant congenital naevus.OBJECTIVE: To discuss the characteristics of proliferative nodules in giant congenital naevi. methods: We report the case of a newborn referred for staged curettage of a giant congenital naevus. A nodule was discovered on his left flank. It was excised for analysis during the first treatment session during the second week of life. RESULTS: The nodule was soft and looked like a lipoma. On optical microscopy however, there was a high cellular density and a high number of mitoses. Although the genetic analysis for melanoma antigens was reassuring, a firm nodule recurred a few days later. A second excision was performed at the fourth week. Surprisingly, on optical microscopy, the cellular density was much lower and there were no more atypias or mitoses; many neurotization foci were present. The natural history changed to spontaneous regression of the cellular activity. The diagnosis of proliferative nodule was made. CONCLUSION: Proliferative nodules in giant congenital naevi have specific clinical and histological characteristics. These should however be put into perspective. As demonstrated in this case, there can be an initial high mitotic activity within the nodule but this should not lead to the misdiagnosis of malignant melanoma. The spontaneous regression of cellular activity will allow the correct diagnosis to be made.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/16. Porokeratotic eccrine ostial and dermal duct nevus. An abnormally keratinizing epidermal invagination or a dilated, porokeratotically plugged acrosyringium and dermal duct?Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) has been said to represent a widely dilated, keratin-plugged acrosyringium and dermal duct. We have observed in a case of congenital PEODDN a normal-appearing, acrosyringium-like duct that traverses vertically the entire length of the parakeratotic column. Also, in its lower course, it stained positively for carcinoembryonic antigen, while the inner borders of the invagination from which the parakeratotic column arose stained negatively. This leads us to suggest that the epithelial structure in PEODDN is an abnormally keratinizing epidermal invagination through which an acrosyringium-like duct traverses, rather than an abnormally dilated, parakeratotically plugged acrosyringium and dermal duct.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/16. Rapid perinatal growth mimicking malignant transformation in a giant congenital melanocytic nevus.Transformation to malignant melanoma in a giant congenital melanocytic nevus observed on the right limb of a 3,300-g newborn boy was strongly suggested by the histologic features of its ulcerated and papular areas: atypical melanocytes, irregular melanin distribution, many mitotic figures, "pagetoid" invasion of the dermis, and destruction of the rete ridges. Electron microscopy, too, showed that the atypical melanocytes had irregularly shaped and folded nuclei, one or more nucleoli, and a cytoplasm rich in organelles and polymorphous melanosomes. Investigation with a panel of monoclonal antibodies, on the other hand, revealed the antigen phenotype of a proliferative melanocytic lesion unaccompanied by the plain expression of antigens usually observed in malignant melanoma. In addition, the clinical picture during a 2-year follow-up has been free from signs of locoregional and systemic progression.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
6/16. Malignant melanoma simulants arising in congenital melanocytic nevi do not show experimental evidence for a malignant phenotype.Proliferative neoplasms that resemble malignant melanoma may develop in large congenital melanocytic nevi, prenatally or in the neonatal period, although these lesions rarely show the progressive growth or behavioral characteristics of melanoma. This report describes the genetic, biologic, and immunologic characteristics of six tissue culture cell lines derived from two neoplasms present in congenital melanocytic nevi in two newborn infants. Both neoplasms had clinical and histologic features of malignant melanoma. Despite these features, cells from all lines were phenotypically benign, as evidenced by a normal karyotype, their expression pattern of pigment cell-associated antigens, absence of melanoma-associated ganglioside GD2, their mitogenic response to the tumor-promoting phorbol ester 12-0-tetradecanoyl phorbol-13-myristate, their inability to grow anchorage independently in soft agar, and prolonged but finite life span. The cells did not produce tumors in nude mice, but they remained viable at the injection site for over 7 months.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/16. Halo giant congenital melanocytic nevus: in vitro immunologic studies.We have assessed in vitro humoral and cell-mediated immune reactions of a patient with a giant congenital melanocytic nevus that showed clinical and histologic evidence of spontaneous regression. nevus cell-specific antibody was detected in the patient's serum, which was cytotoxic to epidermal cells isolated from the pigmented nevus and specifically to cells of a human melanoma line in a complement-dependent fashion. The presence of epidermal langerhans cells, known to be antigen-presenting cells, was required for nevus cell-specific activation of the patient's T lymphocytes. Antibody-independent inhibition of melanoma cell growth was detected by the use of the patient's mononuclear cells. Therefore both humoral and cell-mediated immunity may be involved in nevus cell rejection and halo formation.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/16. Multiple agminate Spitz naevi: review of the literature and report of a case with distinctive immunohistological features.We describe a 13-year-old girl with multiple pigmented nodules and plaques arranged in a cluster in the right lumbar region, which had developed since infancy. Eleven of 15 lesions which were examined histologically were found to be Spitz naevi. The remaining four lesions were compound naevocellular naevi, and two of them showed focal dysplasia. Eight Spitz naevi were investigated immunohistologically with monoclonal antibodies against HLA-antigens and malignancy-associated melanocytic antigens which are rarely present in common naevi. Naevus cells in all lesions expressed HLA-ABC antigens, but lacked HLA-DR antigens in seven of the eight lesions. All naevi were positive for 'constitutive' (KG-6-56) and 'early' (K-1-2) markers of naevomelanocytic cells. In five of the eight Spitz naevi, at least one of the three malignancy-associated melanocytic antigens PAL-M1, A-1-43 and A-10-33 was found. The expression of malignancy-associated antigens in multiple agminate Spitz naevi is at variance with their benign clinical course.- - - - - - - - - - ranking = 6keywords = antigen (Clic here for more details about this article) |
9/16. Cellular blue nevus ("melanocytoma") of the spinal meninges: electron microscopic and immunohistochemical features.A primary cellular blue nevus (melanocytoma) of the spinal canal in a 21-year-old woman is reported. light microscopic examination revealed a melanotic neoplasm with histological patterns resembling schwannoma, dermal nevi, and neuroblastic-like tumor. The ultrastructural features of the neoplastic cells were similar to those in dermal blue nevi and melanomas. There was no evidence of arachnoidal cell differentiation. immunohistochemistry revealed positive reactions for S-100 protein and neuron-specific enolase in many cells and no reactions for glial fibrillary acidic protein, cytokeratins, epithelial membrane antigen, 70-kD neurofilament protein, or Leu-7. vimentin was strongly positive in the melanocytic cells as well as in the arachnoidal cells of involved meninges. The ultrastructural and immunohistochemical features support the nevoid nature of this tumor, which is frequently mislabeled as "melanotic meningioma."- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/16. Disseminated eruptive nevocellular nevi.A 13-year-old boy suddenly developed about 2,000 dark brown to black colored papules on his face and neck and about 500 lesions on his trunk and upper extremities during a six month period. Histopathologic features were compatible with junctional nevus. The results of alpha melanocyte stimulating hormone (MSH), proliferating cell nuclear antigen (PCNA), and epidermal growth factor receptor (EGF/R) studies are presented. To the best of our knowledge, this report represents an outbreak of the highest number of nevocellular nevi in a short period without any malignant nature or evident triggering factor.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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