The potential value of thallium-201 scintigraphy in the diagnosis of squamous cell carcinoma arising from extensive pyoderma

Squamous cell carcinoma (SCC) arises from a variety of premalignant conditions, including pyoderma. However, an accurate diagnosis of SCC is sometimes challenging due to indistinguishable inflammatory lesions. Here, we present a case of SCC arising from extensive pyoderma, which was successfully diagnosed by taking advantage of thallium-201 scintigraphy. A 49-year-old man presented with an elevated tumor on his right buttock. Computed tomography (CT) and enhanced magnetic resonance imaging (MRI) identified the tumor, but many indistinguishable lesions were also found around the tumor. Histopathology revealed an atypical proliferation of keratinocytes with cancer pearls inside the tumor nests, while histopathology of nodules around the tumor revealed inflammatory tissues. Positron emission tomography CT (PET/CT) revealed an accumulation of 2-deoxy-2-[¹⁸ F]-D-glucose at the axillae and inguinal nodes, and at subcutaneous tissues in addition to the tumor. From the CT, enhanced MRI, and PET/CT analyses it was impossible to differentiate many scattered subcutaneous nodules on the trunk from SCCs. However, thallium-201 scintigraphy identified only the tumor and found no accumulation in other nodules. This finding suggests that thallium-201 scintigraphy is useful for the diagnosis of SCC by excluding false-positive signals detected by other imaging technologies.

Diminished fibrinolysis and thrombosis: clinical implications for accelerated atherosclerosis

Obesity is associated with an increased risk of atherosclerotic coronary artery disease. Cytokines and oxygen-centered free radicals implicated in insulin resistance stimulate adipocyte and endothelial production of plasminogen activator inhibitor type-1 (PAI-1), the primary physiologic inhibitor of fibrinolysis, in vitro. In obese hyperinsulinemic animal models simulating insulin resistance, plasma PAI-1 activity is increased. As the cardiovascular risk profile in specific populations may differ, endogenous fibrinolysis in lean and obese subjects was characterized and the mechanisms underlying differences were identified. Obese subjects (body mass index > 26) exhibited increased blood levels of PAI-1 antigen compared with corresponding values in lean controls. Blood t-PA antigen differed as well, yet basal endogenous fibrinolytic activity was decreased because of the high PAI-1 activity. The increased PAI-1 level was associated with increased levels of immunoreactive insulin (IRI). In diabetic subjects, coronary atherectomy specimens exhibited strong positive PAI-1 immunostaining, suggesting that in the diabetic vascular wall, intramural fibrinolytic activity is diminished. Using the oral glucose tolerance test, patients with significant stenosis confirmed by coronary angiography exhibited increased sigmaIRI, sigmaBS, sigmaIRI/sigmaBS, and IRI at 120 min compared to subjects without significant stenosis. IRI at 120 min was closely correlated with the severity of coronary artery disease. These results indicate that adipocyte overproduction of PAI-1 by insulin induces decreased endogenous fibrinolytic activity and contributes to the accelerated coronary macroangiopathy in hyperinsulinemic obese subjects with insulin resistance.

Effect of palmitic acid and fatty acid binding protein on ventricular fibrillation threshold in the perfused rat heart

The effects of increased free fatty acid (FFA) levels on ventricular arrhythmias remain controversial. Using ventricular fibrillation threshold (VFT), we examined the relationship between FFA levels and ventricular arrhythmias. Isolated rat hearts were perfused with palmitate bound to either albumin or fatty acid binding protein (FABP) by Langendorf's method. The VFT was determined by electrical stimulation. Perfusion with 0.12 mM albumin alone, 0.12 mM palmitate bound to 0.12 mM albumin, and 0.36 mM palmitate bound to 0.12 mM albumin did not lower the VFT significantly. However, 0.60 mM palmitate bound to 0.12 mM albumin lowered VFT from 2.19 +/- 0.20 mA to 1.56 +/- 0.13 mA. The perfusion of 0.36 mM palmitate bound to 0.12 mM FABP lowered the VFT from 2.05 +/- to 0.19 mA to 1.47 +/- 0.23 mA, but 0.12 mM FABP alone did not affect the VFT. Perfusion with 0.36 mM palmitate bound to 0.12 mM FABP caused the VFT to fall more than perfusion with 0.36 mM palmitate bound to 0.12 mM albumin. Then the effects of verapamil perfusion or a low concentration of perfusate Ca2+ on VFT were examined. VFT was determined by electrical stimulation. Palmitate (0.6 mM) bound to 0.12 mM albumin lowered VFT. Verapamil 10(-7) M perfusion and a low concentration of Ca2+ (Ca2+ 1.67 mM) suppressed the FFA-induced fall of VFT. These results suggested that the arrhythmogenic action of FFA was related to Ca2+ overload in myocardial cells.

[Postural ventricular tachycardia in patients with pheochromocytoma]

Many kinds of cardiac complications have been reported in association with pheochromocytoma, including transient ECG changes, catecholamine-induced myocardial injury and various types of supraventricular or ventricular tachyarrhythmias. We report a case admitted to our hospital for evaluation of ventricular tachycardia. A 45-year old woman entered the cardiology department with the complaint of recurrent palpitation in a position of ante-flexion. Physical examination at a time of admission revealed a regular pulse of 62/min, blood pressure of 100/56 mmHg (sitting). There was no evidence of cardiac enlargement or congestive heart failure. An ambulatory 24 hour ECG showed recurrent ventricular tachycardia short run with wide QRS at the time of ante-flexion. Urea, electrolytes and complete blood count were normal. Serum cardiac enzymes, thyroid function tests and glucose were normal. An echocardiogram confirmed no specific changes, such as left ventricular hypertrophy. 24 hour urine collection confirmed an elevated vanillylmandelic acid (10.4 micrograms/day: normal 2.0-2.8), metanephrine (0.68 micrograms/day: normal 0.04-0.18) and normetanephrine (1.71 micrograms/day: normal 0.1-0.28). Serum catecholamine level showed adrenalin, 0.26 ng/ml: normal less than 0.12) and noradrenaline (3.34 ng/ml: normal 0.1-0.41). These values increased to 1.34 and 24.75 respectively during palpitation attack. Abdominal enhanced computed tomography showed a 3 cm diameter tissue mass in the left adrenal area. Surgical resection of this pheochromocytoma was accomplished uneventfully. It was successfully excised and the patient was discharged in good health two weeks after the operation. Cardiotoxic effects of catecholamines have been well described by many investigators. In our case, tachyarrhythmia was induced without excessive changes of ECG findings. In patients with pheochromocytoma, occurrence of various types of cardiac arrhythmia should be considered.