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Dermal Nodule (dermal + nodule)
Selected AbstractsCutaneous melanocytoneuroma: the first case of a distinctive intraneural tumor with dual nerve sheath and melanocytic differentiationJOURNAL OF CUTANEOUS PATHOLOGY, Issue 2007Ilan Weinreb Many melanocytic nevi contain areas similar to nerve sheath tumors (NST) and NSTs with melanin have been described. There are some NSTs with at least partial intraneural location, including neurofibromas, plexiform neurofibromas, granular cell tumors and the recently described, dendritic cell neurofibroma with pseudorosettes. We describe the case of an NST with melanocytic differentiation and intraneural location, for which we suggest the term ,melanocytoneuroma' (MCN). It arose in the skin of a 67-year-old woman with no previous history of melanoma or neurofibromatosis. The lesion presented as a papule and histologically consisted of a dermal nodule without junctional melanocytic activity. The lesion comprised an intraneural proliferation of large epithelioid eosinophilic cells with prominent cell borders imparting a ,plant-like' appearance. The cells were also seen within adjacent nerve twigs and were positive for S100, Melan-A, HMB-45, microphthalmia transcription factor and PGP 9.5. The lesion was entirely surrounded by an epithelial membrane antigen-positive-perineurial coat and the individual tumor cells were invested by laminin and collagen type-IV-positive basal lamina-like material. The lesion did not show any evidence of atypia and following complete excision, no recurrence has been documented. In conclusion, this unusual lesion represents an intraneural proliferation with melanocytic and nerve sheath cell differentiation, to which we have accorded the appellation, MCN. [source] Primary Cutaneous Ewing's SarcomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005K.S. Draft A 57-year-old woman presented with a three-week history of an erythematous nodule on her palm. The clinical diagnosis was pyogenic granuloma. Histology revealed a circumscribed dermal nodule of uniform, primitive round cells with numerous mitotic figures and apoptopic cells. The tumor cells showed strong membranous immunoreactivity for CD99 and nuclear immunoreactivity for Fli-1. The tumor cells were negative for S-100 protein, cytokeratin AE1/3, cytokeratin 20, chromogranin, synaptophysin, and actin. The diagnosis of Ewing's sarcoma was made. CT scans showed no evidence of an osseous or deep soft tissue primary tumor or metastatic disease. The tumor was excised with 1 cm margins, and the patient received six courses of adjuvant chemotherapy. One year after diagnosis, the patient is alive without evidence of disease. Extraosseous Ewing's sarcoma (EES) rarely presents as a primary skin tumor and should be considered in the differential diagnosis of small round cell tumors involving the skin. It is important to distinguish primary cutaneous EES from secondary involvement of the skin by ES, as primary cutaneous EES has a more indolent course compared to classic EES or osseous ES. Immunohistochemical stains for CD99 and Fli-1 are useful markers to confirm the diagnosis of cutaneous ES. [source] Myoepithelioma of the Skin with P63 ExpressionJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005M.J. Smith-Zagone A case of cutaneous myoepithelioma is reported. A 37 year-old woman presented with a 2 cm well-circumscribed dermal nodule of the forehead. The tumor was enucleated with the clinical diagnosis of an epidermal inclusion cyst. Histologically, the tumor was located within the dermis and was well circumscribed. It was composed of spindle-shaped and epithelioid cells arranged in organoid nests. Focal areas of extracellular hyalinized stroma were present. Well-defined glandular structures, chondroid matrix, and significant nuclear pleomorphism were absent. The tumor expressed widespread cytoplasmic positivity for cytokeratin (using AE1/AE3) and nuclear positivity for p63. Variable reactivity was noted with EMA and S-100. The tumor was negative for smooth muscle actin, GFAP, chromogranin, synaptophysin, and CEA. These immunohistochemical results supported myoepithelial differentiation. Myoepitheliomas of the skin are rare neoplasms that have only recently been recognized in the skin. A single publication has reported the diagnostic utility of p63 in the diagnosis of myoepithelial tumors of the skin. Myoepitheliomas often display variable expression of myoepithelial markers, with no single marker that is 100% sensitive. The current case highlights the need for a battery of markers, including p63, to detect myoepithelial differentiation. [source] Case of cystic schwannomaTHE JOURNAL OF DERMATOLOGY, Issue 11 2008Yu Sung CHOI ABSTRACT Schwannoma is a well-defined tumor arising from the nerve sheath. It may present as a solitary mass in any part of the body, but is more commonly seen in the head, neck and extremities. We describe a 32-year-old female patient with a small dermal nodule on the forehead, which was 2 cm in diameter, round and of a cystic nature. Microscopic examination revealed that it consisted of compact spindle cells arranged partly in short bundles or a fascicular pattern with outstanding cystic degeneration manifested as a large, unilocular cavity in the center of the tumor tissue. The tumor cells were positive for S-100 protein and negative for epithelial membrane antigen (EMA), while the tumor capsule was positive for EMA. There was no S-100-positive membrane-like structure lining the cyst wall. [source] Congenital panfollicular nevus: report of a new entityJOURNAL OF CUTANEOUS PATHOLOGY, Issue 1 2005Laura S. Finn The various forms of non-melanocytic nevi (hamartomas) are usually encountered in pediatric patients, and nevus sebaceous of Jadassohn is the most common to have undifferentiated pilosebaceous units. We report a unique congenital follicular nevus that fails to meet the criteria of any previously described follicular neoplasm, despite the plethora of alternatives. Clinically considered a syringocystadenoma papilliferum, the excised lesion contained multiple dermal nodules that exhibited nearly all stages of follicular differentiation. The periodicity of the follicular proliferations was akin to normal terminal hair, and a prominent perifollicular sheath surrounded each. This benign lesion of abortive hair follicles was unassociated with any established genodermatous syndrome or other adnexal neoplasm. [source] Dermatofibroma: a possible model of local fibrosis with epithelial/mesenchymal cell interactionJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 4 2009T Yamamoto Abstract Dermatofibromas are benign dermal nodules usually seen on the extremities; however, whether a dermatofibroma is a reactive fibrous hyperplasia or a true neoplasm is still unclear. Fibrous type dermatofibromas might be regarded as the symptom of local fibrotic processes and thus present a possible model of local fibrosis. Interaction between proliferated dermatofibroma fibroblasts and overlying elongated epidermis suggests a relationship between keratinocytes and mesenchymal cells. We herein describe current insights into the pathogenesis of dermatofibromas and explore the possible involvement of immunocytes around fibroblasts and effector cells which play an important role in the development of dermatofibromas. Conflicts of interest None declared [source] | ||||||||||