Journal of the American Academy of Dermatology
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J. Am. Acad. Dermatol. · Feb 2001
Case ReportsCutaneous immunocytoma presenting with multiple infiltrated macules and papules.
Cutaneous immunocytomas are low-grade malignant B-cell lymphomas that arise in the skin as solitary or multiple papules, plaques, or nodules. We describe a female patient with lymphoplasmocytic lymphoma who presented with multiple, brown-red to bluish macules and papules on the left thigh. The proliferation was monoclonal as evaluated by positive staining of the plasma cells with antibodies against IgG heavy chain and lambda-light chain and with polymerase chain reaction showing immunoglobulin heavy-chain gene rearrangement. Neither paraproteinemia nor involvement of bone marrow was present.
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J. Am. Acad. Dermatol. · Feb 2001
Case ReportsA novel KIT mutation results in piebaldism with progressive depigmentation.
Piebaldism is an autosomal dominant disorder of melanocyte development characterized by white skin (leukoderma) and white hair (poliosis). In general, piebaldism has been distinguished from vitiligo by the presence of lesions from birth, the hyperpigmented macules of depigmented and normal skin, and the static course. We hypothesized that an 8-year-old girl and her mother who had unusual piebaldism of a progressive nature would have a novel mutation of the KIT gene, the gene that is altered in patients with piebaldism, or of the MITF (microphthalmia activating transcription factor) gene, which would be expected to cause type II Waardenburg syndrome, but is associated with a phenotype of progressive depigmentation in mice. ⋯ Genetic analysis of genomic DNA from both the mother and daughter with progressive piebaldism revealed a novel Val620Ala (1859T>C) mutation in the KIT gene, which was not detected in family members without progressive piebaldism or in 52 normal control individuals. This KIT mutation affects the intracellular tyrosine kinase domain and thus predicts a severe phenotype, as was the case in this family. Although other KIT mutations in the vicinity of codon 620 lead to the standard phenotype of static piebaldism, the Val620Ala mutation is novel and may result in a previously undescribed phenotype with melanocyte instability, leading to progressive loss of pigmentation as well as the progressive appearance of the hyperpigmented macules.
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J. Am. Acad. Dermatol. · Feb 2001
Differential expression of active mitogen-activated protein kinase in cutaneous endothelial neoplasms: implications for biologic behavior and response to therapy.
Tumors of endothelium range from benign hemangiomas of infancy to highly malignant angiosarcomas of the elderly. Hemangiomas are the most common tumors in infants and may affect up to 10% of all children. The biologic behavior of these lesions ranges from self-resolving, in the case of hemangiomas and pyogenic granulomas, to lethal metastatic neoplasms in the case of angiosarcoma. Although the clinical outcomes of these diseases are easily distinguished, the biologic basis for these differences is not well understood. Activation of mitogen-activated protein kinase (MAPK) is an important signal transduction mechanism that may predict response of a tumor to chemotherapy. ⋯ We demonstrate that the use of antibodies specific for signal transduction pathways is feasible in paraffin-fixed tissue. Thus the activity of a given signal transduction pathway can be ascertained in a biopsy specimen. Immunohistochemistry for phosphorylated MAPK may help the pathologist distinguish benign from malignant endothelial processes and thus guide therapy.
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J. Am. Acad. Dermatol. · Dec 2000
Leg ulcers in peripheral arterial disease (arterial leg ulcers): impaired wound healing above the threshold of chronic critical limb ischemia.
Peripheral arterial disease is the only identifiable etiology in approximately 10% of leg ulcers. Clinical data on the management of these chronic wounds are scarce. ⋯ Most arterial leg ulcers do not meet the criteria of chronic critical limb ischemia, but they do not heal under conservative measures, either. A majority of these patients benefit from revascularization and should, therefore, be referred for arterial duplex ultrasound investigation or angiography. In our study, an ankle pressure below 110 mm Hg identified all patients (100%) who were subjected to revascularization procedures. However, controlled clinical studies are required to find the systolic ankle pressure and ABI below which revascularization can be recommended to speed up the healing time.
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J. Am. Acad. Dermatol. · Nov 2000
ReviewMerkel cell carcinoma: report of 10 cases and review of the literature.
Merkel cell carcinoma (MCC) is a rare primary neuroendocrine skin tumor that usually arises in the head and neck or the extremities of elderly patients. Because of the limitation of retrospective data, optimal treatment is not well defined. ⋯ MCC has a high incidence of locoregional recurrence with distant metastases that is more common with higher stage lesions. Early local management of smaller lesions results in good long-term survival. It is not known whether prophylactic lymph node dissection and/or radiation and adjuvant radiation increases survival. Long survival can be achieved after treating locoregional recurrence. The role of chemotherapy is still controversial and should be considered in patients with advanced disease and those not thought to be candidates for surgery.