1/298. Epithelioid cell histiocytoma: a simulant of vascular and melanocytic neoplasms.Epithelioid cell histiocytoma (ECH) is an unusual and still poorly recognized variant of benign fibrous histiocytoma. Epithelioid cell histiocytoma differs from most benign fibrous histiocytomas in five important ways: the predominance of epithelioid cells, relative lack of secondary elements (such as giant cells, foamy, or hemosiderin-laden macrophages), relative sharp circumscription, prominent vascularity, and centering in the papillary dermis in most cases. A strong resemblance to melanocytic and vascular lesions has been noted, and a recent case was reported with features suggesting endothelial origin. Fifteen new cases of ECH, including one example of the rare deep cellular variant, are presented herein, with emphasis on features mimicking vascular and melanocytic neoplasms. Labeling with endothelial markers, including previously unreported CD-31 labeling, showed abundant vascular staining, which may be challenging to interpret, but which does not indicate an endothelial origin of ECH.- - - - - - - - - - ranking = 1keywords = melanocytic (Clic here for more details about this article) |
2/298. Microvascular reconstruction of the skull base: indications and procedures.PURPOSE: The aim of the current study was to review the use of free tissue transfer for reconstruction of the skull base and for coverage of intracranial contents. patients AND methods: From 1990 until 1996, revascularized flaps were transferred to the skull and the skull base in 11 patients in whom intracranial/extracranial resection of tumors of the skull base was performed in cooperation with the Department of neurosurgery. The defects resulted from removal of squamous cell carcinomas (n = 4), basal cell carcinomas (n = 4), malignant melanoma, malignant schwannoma, and malignant meningioma. Defect repair was accomplished by revascularized transfer of latissimus dorsi muscle flaps in seven cases and rectus abdominis flaps and forearm flaps in two cases each. In five patients with extensive intracranial tumor spread, reconstruction was performed for palliative reasons. RESULTS: A safe soft tissue closure of the intracranial and intradural space was achieved in all patients, whereas the contour of the facial skull and the neurocranium was satisfactorily restored at the same time. By using the entire length of the grafted muscle, the vascular pedicle could be positioned next to the external carotid artery and conveniently connected to the cervical vessels. The mean survival time of the patients with palliative treatment was 8.4 months, with an average duration of hospital stay of 24.5 days. CONCLUSIONS: Despite the increased surgical effort of revascularized tissue transfer, microvascular reconstruction of large skull base defects appears to be justified, even as a palliative measure.- - - - - - - - - - ranking = 0.0047644963766542keywords = schwannoma (Clic here for more details about this article) |
3/298. Metastatic melanoma to the skin simulating blue nevus.Cutaneous metastases from melanoma can mimic primary melanoma and melanocytic nevi. Recognition of a metastatic lesion is of great importance for proper staging and treatment decisions. In this study, a potential diagnostic pitfall is described and discussed: dermal metastases from cutaneous melanoma simulating blue nevus, a phenomenon that has received little attention. Ten blue nevus-like lesions from three patients are presented. All contained pigmented melanocytes and melanophages in variable proportions arranged in a blue nevus-like growth pattern. The blue nevus-like metastases occurred in the same anatomic region as the primary tumor or, as in one patient, near the skin scar of a dissected lymph node metastasis. Histologic clues of metastatic melanoma included the presence of atypical epithelioid melanocytes, mitotic figures, and an associated inflammatory cell infiltrate at the periphery of the lesion. Although such histologic features facilitate the recognition of a metastasis, clinical correlation is essential for a definitive diagnosis.- - - - - - - - - - ranking = 0.16666666666667keywords = melanocytic (Clic here for more details about this article) |
4/298. Inflammatory metastatic melanoma.An 87-year-old woman developed erythema, induration and tenderness of the skin overlying each breast. One year before, she had undergone an axillary lymph node dissection because of metastases from melanoma. The primary site was unknown. A skin biopsy showed pigmented tumor nests within the dermal lymphatic vessels, and immunohistochemistry confirmed the melanocytic origin. The diagnosis of inflammatory metastatic melanoma was made.- - - - - - - - - - ranking = 0.16666666666667keywords = melanocytic (Clic here for more details about this article) |
5/298. Desmoplastic malignant melanoma on the buttock of an 18-year-old girl: differentiation from desmoplastic nevus.Melanocytic proliferation in young people may sometimes pose a diagnostic dilemma. This is particularly so when a desmoplastic component is present. Because the two main differential diagnoses, desmoplastic malignant melanoma and desmoplastic Spitz nevus, share some morphologic features, the diagnosis of desmoplastic malignant melanoma may be overlooked. Distinction between the two is important because they show completely different biological behavior. The age of patient, site of lesion, histologic findings of melanocytic atypia, neurotropism, mitosis, and maturation help to distinguish the two entities. We report a case of desmoplastic malignant melanoma occurring in the buttock of an 18-year-old Chinese girl. Histologically, it had typical features of desmoplastic malignant melanoma with junctional melanocytic atypia and prominent neurotropism. Clinical and histologic differences between desmoplastic malignant melanoma and desmoplastic Spitz nevus are reviewed. We conclude that although desmoplastic Spitz nevus occurs much more commonly in adolescents, desmoplastic malignant melanoma can occur in this age group and even in non-sunexposed skin. Microscopic findings remain the mainstay that guides the final diagnosis.- - - - - - - - - - ranking = 0.33333333333333keywords = melanocytic (Clic here for more details about this article) |
6/298. Malignant melanoma of the choroid in neurofibromatosis.A 60-year-old white woman with generalized neurofibromatosis and multiple melanocytic hamartomas of the iris developed an unusual choroidal mass, with secondary sensory retinal separation in the left eye. Ophthalmoscopically the tumor had a peculiar donut configuration that was caused by a large focus of central necrosis within a spindle B melanoma.- - - - - - - - - - ranking = 0.16666666666667keywords = melanocytic (Clic here for more details about this article) |
7/298. Malignant melanoma showing ganglioneuroblastic differentiation: report of a unique case.We report a case of metastatic malignant melanoma in an inguinal lymph node, expressing ganglioneuroblastic differentiation. This was characterized by the presence of discrete nests and islands of large ganglion cells with abundant cytoplasm and eccentric nuclei with prominent nucleoli admixed with smaller primitive neuroblasts. The cells were separated by pale pink fibrillar material representing neuritic cell processes. These foci of ganglioneuroblastoma were seen over a background of an otherwise typical metastatic epithelioid, focally melanotic, malignant melanoma. immunohistochemistry showed positivity for neurofilament, synaptophysin, chromogranin, vasoactive intestinal peptide, and glial fibrillary acidic protein in the areas with ganglioneuroblastic differentiation, but not in the melanocytic component. Conversely, HMB45 positivity was expressed by the melanocytic cells only. S-100 protein and Melan-A, a putative melanocytic marker, showed positivity in both melanocytic and ganglioneuroblastic components. Ultrastructurally, neuritic cell processes and dense core neurosecretory granules were identified in the ganglionic and neuroblastic cells. A subsequent nodal metastasis in the same region showed focal neuroblastic differentiation without the ganglionic element. No evidence of neuronal or ganglionic differentiation was seen in the primary skin melanoma.- - - - - - - - - - ranking = 0.66666666666667keywords = melanocytic (Clic here for more details about this article) |
8/298. Tapioca melanomas of the iris: immunohistology and report on two cases.BACKGROUND: Tapioca-like tumors are rare, and their benign or malignant nature is obscure without histological work-up. We report on the clinical and histological features of different types of tumors in two patients. CASE REPORT: Two patients aged 17 and 45 years presented with brownish iris masses increasing in size. Full-thickness en bloc excision of melanocytic tumors (5.5 mm and 7.0 mm in diameter) was carried out. Histological work-up revealed a nevus cell nevus in the young patient and an epithelioid malignant melanoma in the middle-aged patient evolving from the ciliary body. Staining for HMB-45 was marked in both tumors, for S-100 low in the nevus and marked in the melanoma, and for p53 negative in the nevus and positive in the melanoma. Ki67 stains were negative. CONCLUSION: We propose that excision of anteriorly located pigmented tumors that increase in size is indicated in order to determine whether they are benign or malignant. In these case reports, tapioca-like tumors include a benign and a malignant entity. To our knowledge, a nevus cell nevus presenting as a tapioca-like tumor has not previously been described. Curative surgery and histological and immunohistological evaluation are required to characterize the malignant potential of these tumors and the prognosis.- - - - - - - - - - ranking = 0.16666666666667keywords = melanocytic (Clic here for more details about this article) |
9/298. blindness as a consequence of a paraneoplastic syndrome in a woman with clear cell carcinoma of the ovary.BACKGROUND: paraneoplastic syndromes are rare conditions associated with cancer that result in serious disease states at unique sites. In 1982, a report of bilateral diffuse uveal melanocytic proliferation associated with nonocular cancers which resulted in blindness was reported. We present a case of a woman with recurrent ovarian cancer who developed this paraneoplastic syndrome. CASE: A 55-year-old woman had been diagnosed in 1990 with an ocular melanoma of her right eye and in 1994 with clear cell carcinoma of the ovary. With recurrence of ovarian cancer, new eye lesions were identified in both eyes. After enulcleation of her right eye, an ocular melanoma and diffuse bilateral melanocytic proliferation (BDUMP) were found. The sight in her left eye continued to deteriorate as other signs of BDUMP occurred in the eye. Within 1 month of diagnosis, the patient was blind. She subsequently succumbed to progression of ovarian cancer. CONCLUSION: Recurrent ovarian cancer is usually an intraabdominal disease that results in gastrointestinal dysfunction. This case illustrates a rare paraneoplastic syndrome associated with ovarian cancer that mimics metastatic disease to the eye, but has a different pathophysiology.- - - - - - - - - - ranking = 0.33333333333333keywords = melanocytic (Clic here for more details about this article) |
10/298. breast carcinoma diverging to aberrant melanocytic differentiation: a case report with histopathologic and loss of heterozygosity analyses.A case of primary breast cancer showing differentiation to malignant melanoma is reported. To obtain insight into the clonal relationship between the two components of the tumor, polymerase chain reaction-based microsatellite analysis to detect loss of heterozygosity on chromosome arms 1p, 1q, 3q, 4q, 6q, 8p, 9p, 10q, 11q, 13q, 16q, 17p, 17q, and 18q with microdissected tissues of both components was performed in addition to histologic, histochemical, immunohistochemical, and ultrastructural techniques. The tumor consisted of a combination of carcinoma and melanoma with morphologic transition. Metastases in the lymph nodes and thoracic spinal bone marrow showed dual tissue structure. One of the metastatic lung tumors showed melanomatous tissue structure. The abundant pigment in the cells was positive for Fontana-Masson staining and bleached with potassium permanganate. The carcinoma component was positive for epithelial membrane antigen and CA19-9, but the melanoma component was negative. Conversely, the melanoma component was positive for HMB45 and vimentin, but the carcinoma component was negative. Electron microscopic analysis showed premelanosomes and melanosomes in the melanoma component. Microsatellite analysis showed the same genetic alterations with loss of heterozygosity on chromosome arms 1p, 3q, 4q, 6q, 9p, 10q, 11q, 13q, 16q, 17p, and 17q in in situ, invasive, and metastatic foci. We concluded that the carcinoma and melanoma components had arisen from the same clone and that this breast carcinoma might have diverged to aberrant malignant melanoma through multiple genetic alterations in the early period of ductal carcinoma in situ.- - - - - - - - - - ranking = 0.66666666666667keywords = melanocytic (Clic here for more details about this article) |
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