Marshall-Smith Syndrome: Report of a Case and Review of the Literature

ABSTRACT Marshall-Smith syndrome is a rare disorder characterized by accelerated skeletal maturation, bullet-shaped proximal and middle phalanges, dysmorphic facial features, and failure to thrive, and is often associated with mental retardation of variable degree. We describe an 8-month-old female with this syndrome, who has a hypoplastic corpus callosum and extreme upper airway obstruction requiring tracheostomy. Also, we review the previous reports of this syndrome since 1971 (Marshall et al., 1971).     

Idiopathic retroperitoneal fibrosis associated with IgG4-positive-plasmacyte infiltrations and idiopathic chronic pancreatitis

Idiopathic retroperitoneal fibrosis (IRPF) is an inflammatory fibrosclerosing condition, leading to renal failure by obstruction of the ureters. Idiopathic chronic pancreatitis associated with marked inflammatory infiltrates has recently been referred to as autoimmune pancreatitis (AIP), and infiltrating plasmacytes carrying immunoglobulin-gamma type 4 (IgG4) are relevant to its pathogenesis. The case is described herein of IRPF associated with subclinical pancreatitis that was most probably AIP in a 70-year-old man. Biopsy specimens of the retroperitoneal pseudotumor revealed a marked lymphoplasmacytic infiltration with dense fibrosis. Infiltrating plasma cells were immunoreactive for anti-IgG4 antibodies. Subsequent systemic examinations showed an extremely elevated serum IgG4 level and pancreatitis concordant with AIP. Following oral steroid administration, the serum IgG4 level normalized, although the appearance of the pseudotumor did not alter. Some AIP cases have been associated with idiopathic fibrosclerosing disorders including IRPF, but histological evidence of IgG4-related IRPF has rarely been provided.     

Multimeric composition of plasma von Willebrand factor in chronic myeloproliferative disorders

Summary In chronic myeloproliferative disorders (CMPD) thrombohaemorrhagic complications occur occasionally in association with thrombocytosis. We studied the multimeric composition of plasma von Willebrand factor (vWf) in 15 patients with polycythaemia vera (PV), 12 with essential thrombocythaemia (ET) and eight with primary myelofibrosis (PMF). The relative content of large (multimer band ≥ 11) multimers calculated by densitometer scan following SDS-agarose gel electrophoresis was 18.5 ± 4.4% (mean±SD) in normal controls, 8.3 ± 7.9% in PV, 8.1 ± 4.6% in ET and 19.6 ± 6.7% in PMF. The patients with PV and ET but not PMF had a significantly lower percentage of large multimers than normal controls (P < 0.001). The relative content of large multimers was negatively correlated with WBC and platelet count (P < 0.02 each) in PV. It was negatively correlated with platelet count (P < 0.005) and was positively correlated with a ratio of ristocetin cofactor/vWf antigen (RCof/vWf: Ag)(P < 0.01) in ET. These results indicate that acquired defects of vWf are quite common in PV and ET but not in PMF. In addition, some CMPD patients with high platelet counts completely lacked large multimers. The negative correlation of the relative content of large multimers with platelet count suggests that large multimers may be preferentially consumed during thrombocytosis or degraded by protease(s) from increased blood cells.     

Specific Electrocardiographic Features of Manifest Coronary Vein Posteroseptal Accessory Pathways

Coronary Vein Accessory Pathways. Introduction: Some posteroseptal accessory pathways (APs) can be successfully ablated by radiofrequency current only from inside the coronary sinus (CS) or its branches, because of an absolute or relatively epicardial location. The aim of this study was to identify ECG features of manifest posteroseptal APs requiring ablation in the CS or the middle cardiac veins (MCVs). Methods and Results: One hundred seventeen consecutive patients with manifest posteroseptal APs successfully ablated: (1) ≥ 1 cm deep inside the MCV (group MCV: n = 13); (2) inside the CS, including the area adjacent to the MCV ostium (group CS: n = 10); (3) at the right (group R: n = 60); or (4) the left posteroseptal endocardial region (group L: n = 34) were included. We reviewed delta wave polarity (initial 40 msec) and QRS morphology during sinus rhythm and atrial pacing as well as electrogram characteristics in these patients. The local target site electrogram in groups MCV and CS was characterized by a longer atrial to ventricular electrogram interval, suggesting a longer course of the pathway and more frequent recording of a presumptive AP potential compared to the group ablated at the right or left endocardium. The most sensitive ECG feature for group CS or group MCV was a negative delta wave in lead II in sinus rhythm (87%), but specificity (79%) and positive predictive value (50%) were relatively low. A steep positive delta wave in aVR during maximal preexcitation possessed the highest specificity and positive predictive value (98% and 88%, sensitivity 61%) which increased to 99% and 91%, respectively, when combined with a deep S wave in V₆ (R wave ≤ S wave). Conclusion: These data suggest that posteroseptal APs ablated inside the coronary venous system have highly specific features, including the combination of a steep positive delta wave in lead aVR and a deep S wave in lead V₆ (R wave ≤ S wave) during maximal preexcitation. The highest sensitivity is provided by a negative delta wave in lead II. These findings may be helpful for anticipating and planning an epicardial ablation strategy.