1/13. Aggressive epithelioid hemangioendothelioma of the lower extremity: a case report and review of the literature.A case of epithelioid hemangioendothelioma (EHE) of the left lower extremity in a 50-year-old male is discussed. The neoplasm presented as a tan-purple, painful mass involving the fourth digit of the left foot. Following an excisional biopsy and partial amputation of the fourth digit, the lesion recurred with a multifocal distribution. A physical exam following the recurrence demonstrated multiple palpable lymph nodes in the left inguinal region. A complete amputation of the fourth digit was performed in conjunction with local excisions of the remaining lesions. Additionally, an inguinal lymphadenectomy was performed for staging purposes. Histologically, the tumor was predominantly composed of epithelioid endothelial cells forming nests, cords, and sheets and occasionally forming irregular, primitive vascular structures. Less commonly, nests of tumor cells assumed a spindled morphology. Patches of necrosis and hemorrhage were apparent throughout the neoplasm. There was minimal atypia and mitoses were not identified. Immunohistochemical stains for CD34, CD31, and ulex europaeus antigens were positive in tumor cells. This case illustrates the potential aggressive behavior of this rare neoplasm and argues against the designation "tumor of low-grade malignancy" with which it is commonly attributed.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/13. Primary extracranial meningioma of the foot: a case report.We present a rare case of primary extracranial meningioma in a 36-year-old man, who had a solitary multinodular mass located in the plantar muscle of the foot. The histology of specimens from simple excision was typical of meningioma, showing bland spindle cell proliferation with a whorl pattern. Immunohistochemical analysis demonstrated that the tumor cells showed diffuse and strong positivity for epithelial membrane antigen as well as moderate reactivity for cytokeratin and vimentin. Ultrastructurally, the tumor cells were characterized by thin bipolar cytoplasmic processes and joined by multiple small desmosomes. There were frequent pinocytotic vesicles and a distinct external lamina on the cell surface. These findings suggest that this primary ectopic meningioma, arising in the soft tissue, may have been derived from perineurial cells of the peripheral nerve, but was morphologically distinguishable from perineurioma. Primary extracranial meningioma should be included in the differential diagnosis of soft-tissue spindle cell tumors, especially those of peripheral nerve origin.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/13. Malignant hidradenoma--a case report demonstrating insidious histological and clinical progression.A histologically benign hidradenoma, occurring in a 15-year-old female inadequately excised at first procedure, recurred locally over the course of 11 years and exhibited first local and subsequently regional metastatic spread. The insidious progression was associated with increasing cytological atypia and alteration of epithelial antigenic expression. In view of the rarity of malignant sweat-gland tumours and consequent lack of a specific treatment protocol, this case serves to emphasize the importance of adequate primary local excision, with histological confirmation of clearance, in the management of sweat-gland tumours.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/13. Spindle cell hemangioendothelioma: report of three cases.Three cases of spindle cell hemangioendothelioma were studied. Two had multiple nodules and the third had a single, recurrent lesion in the dermis or subcutis of the distal extremities. The tumor initiated at the age of 3 months in one patient and at the ages of 11 or 12 years in the remaining two. Local recurrence after surgical excision was observed in all cases. Microscopically the tumors were composed of two components; cavernous blood spaces and a proliferation of spindle cells. Among these spindle cells, there were occasional epithelioid endothelial cells with intracytoplasmic lumina. Phleboliths were observed in two cases. Most of the endothelial cells lining the cavernous spaces were positive for factor viii-associated antigen in all cases; the intracytoplasmic lumina were also positive in two cases. The spindle cells were negative for that antigen in all cases. However, they were positive for desmin in one case. Electronmicroscopically, the spindle cells resembled primitive mesenchymal cells.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
5/13. Ultrastructural, immunocytochemical, and cytogenetic characterization of a human epithelioid sarcoma cell line (RM-HS1).A cell line (RM-HS1) derived from a human epithelioid sarcoma was established in tissue culture. Ultrastructurally, the cells show features of those found within the primary tumor. A mixed mesenchymal-epithelial phenotype, defined by reactivity with antibodies to epithelial membrane antigen and to vimentin and keratin intermediate filaments, was found in the tumor, and a similar phenotype persisted in the cultured cells. cytogenetic analysis revealed a mode of 66 chromosomes. With the use of a variety of banding techniques together with in situ hybridization of a 3H-labeled molecular probe for 18s and 28s ribosomal rna genes (pX1r101), the karyotypes were shown to contain extensive numerical and structural rearrangements, with up to 24 marker chromosomes.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
6/13. Sweat gland carcinoma ex eccrine spiradenoma.We herein report two cases of sweat gland carcinoma that arose in association with eccrine spiradenoma. These lesions presented as enlarging masses that previously had been stable for many years. One produced widespread metastasis and death 5 months after diagnosis. Immunohistochemical studies demonstrated an antigenic relationship between the benign and malignant components of sweat gland carcinoma ex eccrine spiradenoma, but ultrastructural analyses showed a paucity of specialized differentiation. This neoplasm appears to display a range of microscopic appearances and has proven fatal in 20% of reported cases.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/13. Three cases of eccrine porocarcinoma.We report three cases of eccrine poroma, present for many years, in which features were seen suggesting transformation from a benign to a malignant tumour. These changes ranged from in situ Bowenoid dysplasia to frankly invasive squamous carcinoma. The most helpful diagnostic feature in distinguishing the origin of the tumours was the presence of strong cytoplasmic staining for carcinoembryonic antigen (CEA) in cells surrounding, and giving rise to, neoplastic ducts and clefts. Dermatopathologists examining eccrine poromata should examine the lesions carefully for any evidence of malignant change.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/13. A case report of synovial sarcoma with translocation (X;18). Application of fluorescence in situ hybridization to paraffin-embedded tissue.A 57-year-old female patient with synovial sarcoma in her right foot had a chromosome abnormality defined as translocation (X;18). The tumour was located in the subcutis, and histological investigation showed monophasic proliferation of oval to spindle-shaped cells with a fascicular arrangement lacking an epithelial component. Immunostaining disclosed no cytokeratin or epithelial membrane antigen in tumour cells. Karyotypic analysis revealed translocation (X;18) in addition to other nonspecific aberrations. fluorescence in situ hybridization was carried out on paraffin-embedded tissue, using dna probes for the centromeres of chromosomes X and 18 with whole chromosome painting probes for X and 18. The free nuclei showed two signals at a rate of 83-85% with the X and 18 centromeric probes, in contrast to three signals at a rate of 68-70% with the X and 18 painting probes.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/13. Perineurial cell differentiation in benign tumors and tumorlike proliferation of peripheral nerves.An unusual, benign, spindle cell peripheral nerve sheath tumor (PNST) is reported that on ultrastructural examination was composed only of perineurial cells. The neoplastic cells showed positive immunoreactivity for S-100 protein and negative immunoreactivity for epithelial membrane antigen; this is not the expected immunophenotype of a perineurioma. Continued examination of benign PNSTs using electron microscopy and immunohistochemistry has the potential to reveal additional variations in the cellular composition and immunophenotype of these soft tissue tumors. PNSTs such as the one described will renew the debate about the cytogenesis of the perineurial cell and its role in PNSTs.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/13. Papillary eccrine adenoma. A case report with immunohistochemical examination.The case of a 52-year-old woman with papillary eccrine adenoma is reported. The lesion presented clinically as a slowly growing nodule on the dorsum of the left foot. Histopathologically, the tumor was composed of multiple, dilated tubular structures lined by two or more layers of epithelial cells. The inner cell layer formed intraluminal papillary projections in some of the tubules. Most of the lumina were filled by eosinophilic granular material. Immunohistochemical examinations that use the avidin-biotin method showed immunoreactivity to S-100 protein, carcinoembryonic antigen, and epithelial membrane antigen. These findings support the hypothesis that papillary eccrine adenoma differentiate toward the secretory epithelium of sweat glands.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
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