1/233. Primary cutaneous Ki-1(CD30) positive anaplastic large cell lymphoma in childhood.Primary cutaneous Ki-1(CD30) positive anaplastic large cell lymphoma (ALCL) is an unusual tumor in the pediatric population. However, the nodal-based form of the disease compared with other histologic subsets of childhood non-Hodgkin's lymphomas (NHL) more frequently involves skin, soft tissue, and bone. The objective of this article is to determine the histologic and immunologic characteristics of childhood primary cutaneous Ki-1(CD30) positive ALCL and its prognosis. The clinical data, histologic features and immunohistochemical profiles of skin biopsy specimens from 3 children with cutaneous Ki-1(CD30) positive lymphoma were reviewed. A literature search was performed and disclosed information on 5 childhood cases. The 3 patients with primary cutaneous Ki-1(CD30) positive ALCL all presented similarly as rapidly growing masses initially and clinically believed to be infectious/reactive processes. The diagnosis was established on the basis of histopathologic examination and immunohistochemical studies. Histologic sections revealed an extensive infiltrate of tumor cells extending throughout the entire dermis into the subcutaneous fat with frank ulceration in 1 patient. No significant epidermotropism was noted. Tumor cells exhibited striking cellular pleomorphism and a high mitotic rate with numerous atypical mitoses. Inflammatory cells were present in all patients. The tumor cells stained positively for Ki-1 antigen (CD30), epithelial membrane antigen, and for T-cell markers (UCHL-1, CD3). One of 3 cases, however, failed to stain for leukocyte common antigen (LCA). No clinically apparent adenopathy was observed in any of the patients. In all instances the patients developed recurrent disease in the skin at sites separate from the primary location. None of the patients demonstrated any involvement of lymph nodes, bone marrow, or other organ systems. All patients were treated with chemotherapy with good response. Primary cutaneous Ki-1(CD30) positive lymphoma is rare in children and is characterized by recurrences. The prognosis seems to be favorable.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
2/233. A case of natural killer/T cell lymphoma of the subcutis resembling subcutaneous panniculitis-like T cell lymphoma.A case of nasal type natural killer (NK)/T cell lymphoma of the subcutis showing clinical and morphological features that resemble subcutaneous panniculitis-like T cell lymphoma (SPTCL) is presented. A 73-year-old man presented with swelling of the left arm and was diagnosed with panniculitis by a dermatologist. It was concluded from a skin biopsy specimen that the patient had non-Hodgkin's lymphoma of the large cell, NK/T cell type because the neoplastic cells showed polyclonal CD3 immunoreactivity. Treatment with interferon-gamma was initiated, but the patient died of disseminated intravascular coagulation and multiple organ failure 2 months after the initial symptoms appeared. However, involvement of additional organs by the lymphoma was not apparent clinically. An autopsy was not performed. A routinely stained section of the biopsy skin specimen revealed massive necrosis of the subcutaneous fat, karyorrhexis admixed with reactive histiocytes, and large atypical lymphoid cells. Immunoreactivity for polyclonal CD3 was present in the perinuclear region, but absent in the neoplastic cell membranes. CD56, CD45RO (UCHL-1), CD43 (MT1), CD45 (leukocyte common antigen), and the cytotoxic molecules perforin, granzyme B and TIA-1 were positive, but CD20 (L26), CD4, CD8, and betaF1 were negative. Epstein-Barr virus (EBV) mRNA was detected in the nuclei of neoplastic cells by in situ hybridization. Subcutaneous panniculitis-like T cell lymphoma is reported to be an EBV-negative, clonal T cell neoplasm. Although this case showed clinical and morphological features that resembled SPTCL, perinuclear polyclonal CD3 staining and membranous CD56 reactivity seen in neoplastic cells were suggestive of NK cells. Furthermore, the neoplastic cells were positive for EBV. This case is considered to be a NK/T cell lymphoma of the subcutis resembling SPTCL. It is believed that it is important to recognize such a tumor because patients may undergo a fulminant clinical course, despite the tumor being localized in the subcutaneous adipose tissue.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
3/233. Malignant rhabdoid tumor of the vulva. Case report.The poor prognosis of malignant rhabdoid tumor is emphasized and histopathological criteria for distinction from epithelial sarcoma of the vulva are discussed. Immunohistochemical analyses were performed by using nine different antigens including vimentin, cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, desmin, muscle-specific actin, S-100 protein, AP-15, neuron specific enolase. This is the sixth reported case of a malignant rhabdoid tumor of the vulva. The patient died eight months after the initial diagnosis in spite of a combination of surgery, adjuvant chemotherapy and external radiotherapy.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
4/233. Primary invasive signet-ring cell melanoma.The histopathological variants of malignant melanoma include the common type (lentigo maligna, superficial spreading melanoma, nodular melanoma, acrolentiginous melanoma), spindle cell, desmoplastic, balloon cell, pleomorphic (fibrohistiocytic), myxoid, small cell melanoma and malignant blue nevus. Recently, signet-ring cell melanoma was introduced as an additional cytologic variant. We describe a 72-year-old patient with a primary signet-ring cell melanoma of the skin located on the upper arm. Histopathologic examination disclosed a melanocytic tumor extending from the epidermis to the deep reticular dermis. Numerous pleomorphic tumor cells showed large, intracellular vacuoles and oval to spindle-shaped nuclei at their periphery. Mitotic figures and multinucleated melanocytes were also observed. Some of the signet-ring cells exhibited cytoplasmatic periodic acid-Schiff (PAS)-positivity. immunohistochemistry showed positive reaction of the tumor cells for S-100, HMB-45 protein and vimentin, confirming their melanocytic differentiation. Tumor cells were negative for cytokeratins, epithelial membrane antigen (EMA), and carcinoembryonic antigen (CEA). The signet-ring cell melanoma disclosed an invasion to Clark Level IV and tumor thickness of 2.2 mm. Signet-ring cell melanoma is a rare morphologic variant of melanoma. Its recognition is important for differentiation from other tumors featuring signet ring cells.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
5/233. Intralesional therapy with anti-CD20 monoclonal antibody rituximab in primary cutaneous B-cell lymphoma.BACKGROUND: We report the use of a new treatment modality in 2 patients with primary cutaneous B-cell lymphoma. In a 58-year-old woman with progressive nodular lesions on the scalp and face, several treatment attempts either failed or could not be used because of severe adverse effects and underlying epilepsy. The patient declined radiotherapy. A 30-year-old man presented with recurrence of tumor nodules occipitally, thoracically, on the arm, and on the right thigh after several excisions. OBSERVATIONS: Intralesional injection of rituximab, a chimeric antibody directed against the CD20 transmembrane antigen present in malignant and normal B cells, resulted in partial regression of tumor nodules. No adverse effects occurred except pain during or shortly after injection and, in one patient, a slight rise in body temperature. Due to the treatment a prolonged complete disappearance of B cells from peripheral blood samples was observed. CONCLUSION: Intralesional rituximab therapy is a nontoxic and effective treatment for cutaneous B-cell lymphoma that deserves further investigation in larger clinical trials.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
6/233. Cytomorphologic features of Merkel cell carcinoma in fine needle aspiration biopsies. A study of two atypical cases.OBJECTIVE: To report atypical cytomorphologic features in fine needle aspiration biopsies (FNABs) from two cases of Merkel cell carcinoma (MCC), a primary neuroendocrine neoplasm of skin. STUDY DESIGN: Retrospective review of FNABs with histologic correlation from six patients with MCC and a report of findings from two whose smears showed atypical features. RESULTS: Typically the aspirates produce highly cellular smears of loosely clustered and individual, relatively monomorphic, small tumor cells with round to oval, regularly contoured nuclei. In two of our cases, the tumor cell nuclei exhibited a spectrum of pleomorphism ranging from moderately complex nuclear membranes with cleaves, indentations and protrusions in one case to large, markedly bizarre, convoluted nuclei and multinucleate tumor cells in the extreme case. Both cases were primary neoplasms, and the diagnosis was based on clinical, histologic and immunohistochemical data. Additionally, electron microscopy was performed on the tumor with bizarre nuclei and demonstrated rare, dense core neurosecretory granules and paranuclear bundles of intermediate filaments.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
7/233. Epidermotropic xanthoma mimicking balloon cell melanoma.Xanthomas of the skin may mimic balloon cell melanoma because 1) both lesions may exhibit a diffuse dermal proliferation of cytologically similar large vacuolated or clear cells with distinct cytoplasmic membranes, 2) dermal maturation (smaller deep dermal nuclei) is absent in both lesions, 3) melanin pigment is usually absent in balloon cell melanoma, 4) cellular atypia may be minimal in balloon cell melanoma, and 5) mitoses may be absent or rare in balloon cell melanoma. We report a unique xanthoma, which further simulated melanoma by exhibiting epidermotropism and a pseudonesting pattern at the dermal-epidermal junction. The correct diagnosis was made with an immunohistochemical panel revealing tumor cell positivity for CD68 and negativity for S-100 protein and MART-1. Immunohistochemical studies may be required in the critical differential diagnosis of epidermotropic xanthoma and amelanotic balloon cell melanoma.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
8/233. Epithelioid sarcoma arising on the nose of a child: a case report and review of the literature.A 4-year-old boy presented with a 6-month history of a red papule on the nasal septum. physical examination was otherwise unremarkable. A biopsy specimen showed an epithelioid sarcoma characterized by nodular collections of epithelioid tumor cells with central, tumor cell necrosis. By immunohistochemistry the tumor cells were positive for cytokeratin, epithelial membrane antigen, vimentin, and CD34, but negative for S-100, CD31, factor viii-related antigen, CD68, actin, desmin and myoglobin. Epithelioid sarcoma is an uncommon tumor of uncertain histogenesis that typically arises in the extremities of young adults. Both the age of our patient and the location of his tumor are unusual, emphasizing the spectrum of presentations that may occur with epithelioid sarcoma. Epithelioid sarcoma should be considered in the differential diagnosis of granulomatous diseases and epithelioid tumors of children, even in unusual locations.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
9/233. T-cell membrane characteristics of "mycosis cells" in the skin and lymph node.In some patients with mycosis fungoides atypical cells ("mycosis cells") are found in the blood. Recently the T-cell membrane characteristics of these atypical cells have been described. In this paper the results of a study of the atypical cells isolated from the lymph nodes and the skin lesions of three patients with mycosis fungoides are presented. Using electron microscopy, it could be demonstrated that the atypical cells formed rosettes with uncoated sheep red blood cells, but not with antibody-complement-coated sheep erythrocytes, indicating the T-cell membrane characteristics of the atypical cells.- - - - - - - - - - ranking = 6keywords = membrane (Clic here for more details about this article) |
10/233. Extraskeletal osteosarcoma of the scalp.A rare case of extraskeletal osteosarcoma of the scalp in a 56-year-old woman is described. At presentation she was found to have an 8-cm diameter, tender, firm, exophytic scalp tumor. MRI scan confirmed absence of underlying skeletal origin and showed extension along the subcutaneous plane. The tumor was excised and the patient received post-operative chemotherapy. Histologically, the tumor showed classical features of an osteogenic osteosarcoma with focal fibroblastic areas. In addition, there were rhabdoid cells present, which showed paranuclear cytoplasmic immunoreactivity for epithelial membrane antigen. The patient developed metastatic disease 6 months after surgical excision.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
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