Review of the Lynch syndrome: history, molecular genetics, screening, differential diagnosis, and medicolegal ramifications

Platelets have a central role in the development of arterial thrombosis and subsequent cardiovascular events. An appreciation of this complex process has made antiplatelet therapy the cornerstone of cardiovascular disease management. However, numerous patients will experience a recurrent atherothrombotic vascular event despite adequate antiplatelet therapy. Individual differences in the rate of platelet activation and reactivity markedly influence normal hemostasis and the pathological outcome of thrombosis. Such an individual variability is largely determined by environmental and genetic factors. These are known to either hamper platelets' response to agonists, and thereby mimic the pharmacological modulation of platelet function or mask therapy effect and sensitize platelets. In this article, we reviewed the antiplatelet mechanisms of aspirin and clopidogrel and the possible role of different polymorphisms, which may affect the efficacy of antiplatelet therapy. Heterogeneity in the way patients respond to aspirin and clopidogrel may in part reflect variation in cyclooxygenase (COX)-1, COX-2, glycoprotein (GP) Ib alpha, GP Ia/IIa, GP IIb/IIIa, UGT1A6*2, P2Y₁, P2Y₁₂, CYP2C9, CYP3A4 and CYP3A5 genotypes.     

Spinal metastases from myxoid liposarcoma warrant screening with magnetic resonance imaging

BACKGROUND: Myxoid liposarcoma (MLS) has an unusual tendency for extrapulmonary metastasis, particularly to the spine and soft tissues. The objective of this study was to determine the prevalence of spinal metastasis, treatment outcomes, and optimal screening method for spinal metastasis in patients with MLS. METHODS: Data from patients with had spinal metastases were obtained from the authors' institutional soft tissue sarcoma database. The accuracy with which positron emission tomography (PET) scans and bone scans identified metastatic lesions was compared with the accuracy of magnetic resonance imaging (MRI). Clinical response to treatment was based on pain, neurologic scores, and survivorship analysis. RESULTS: There were 33 patients who developed spinal metastasis after a median 36 months of follow-up (range, from 7.5 months to 33 years). Known spinal metastases were detected by bone scans in 16% of patients and by PET scans in 14% of patients. Patients who underwent surgery had high-grade spinal cord compression more often than patients who did not undergo surgery (72% vs 19%, respectively; P = .002). Pain and neurologic function were improved or maintained in all patients who received radiation alone (n = 8 patients) and in all but 1 patient who underwent surgery (n = 18 patients). The median overall survival was 51.4 months from the time of primary diagnosis and 21.9 months from the time of first metastasis. CONCLUSIONS: Bone scans and PET scan lack sufficient sensitivity to detect spinal metastasis from MLS. Treatment of metastasis is palliative, but local treatment can yield long-term disease control in select patients. Screening with whole-spine MRI may lead to the earlier detection of spinal metastasis.     

Detection of clinically amelanotic malignant melanoma and assessment of its margins by in vivo confocal scanning laser microscopy.

BACKGROUND: Near-infrared confocal scanning laser microscopy (CSLM) represents a novel imaging technique for in vivo microscopic analysis of skin lesions, including pigmented lesions. OBJECTIVES: To investigate the feasibility of detecting a clinically amelanotic malignant cutaneous melanoma using CSLM and to explore the use of this technique for assessing its margins. PATIENTS AND METHODS: Two lesions from 2 patients were imaged and analyzed using CSLM. Sites suspected to represent melanoma or benign skin on CSLM were marked as such; then, biopsy specimens were obtained for diagnosis using conventional histological analysis. Both lesions were stained for melanin pigment and analyzed immunohistochemically for the expression of melanosomal markers. In 1 case, a biopsy specimen was also examined with electron microscopy. RESULTS: The images obtained using CSLM allowed recognition of an abnormal intraepidermal melanocytic proliferation that was distinctly different from normal skin. Comparison of the sites examined using CSLM and subsequently using conventional histological methods revealed that CSLM correctly identified intraepidermal melanoma and benign skin. Fontana-Masson stains and immunohistochemical and ultrastructural studies showed that clinically amelanotic melanoma cells contained melanosomes and rare melanin granules. CONCLUSIONS: We demonstrated, for the first time, the detection of clinically amelanotic melanoma using CSLM. This technique may aid in the early detection of clinically barely visible or nonpigmented melanomas and may facilitate preoperative noninvasive assessment of their margins.     

Ambiguous phenotypes and genotypes in 16 children with acute leukemia as characterized by multiparameter analysis

Ambiguous phenotypes and genotypes were observed in 16 children with acute leukemia. Surface marker, cytogenetic, molecular genetic, and DNA flow cytometric analyses as well as standard morphologic and cytochemical studies were used to divide the patients into three groups. The first group comprised five children with acute leukemia whose blast cells were morphologically lymphoid, while immunophenotyping disclosed simultaneous expression of early pre-B cell and myeloid features. Molecular genetic studies showed evidence of heavy-chain immunoglobulin (Ig) gene rearrangements in all patients. Cytogenetic data, available in three of these children, revealed t(4;11). In five of the 16 patients, morphologic and surface marker analyses indicated the coexistence of two separate cell populations, one with myeloid and the other with early pre-B cell features. Further evidence of B cell commitment in these patients was provided by demonstration of Ig heavy-chain gene rearrangements in all five patients. Surprisingly, one of the five patients showed oligoclonal Ig heavy-chain as well as monoclonal gene rearrangement for the beta chain of the T cell receptor (beta-TCR). The last group consisted of four cases with otherwise typical acute lymphoblastic leukemia (ALL), early pre-B cell phenotype, and coexpression of myeloid or T cell-associated antigens, and two children with unequivocal acute myeloid leukemia (AML) and coexpression of T cell antigens. Gene rearrangement of Ig heavy-chain could be demonstrated in five of six patients, additional Ig light-chain gene rearrangement in two children with ALL, and bigenotypic features (Ig heavy-chain and beta-TCR gene rearrangement) in one patient. In none of the 16 patients did flow cytometry disclose clonal abnormalities of leukemic cell DNA content. Based on these findings, we suggest that malignant transformation in the first and second group of patients took place at a stage ontogenetically close to the pluripotent stem cell, whereas ambiguous phenotypes in the third group resulted from aberrant gene expression or insufficient reagent specificity.