Familial pheochromocytomas with unusual associations.

Pheochromocytoma occurs in a familial pattern in approximately 10% of patients. Although most familial pheochromocytomas are an expression of the genetic abnormality of neuroectodermal dysplasia or the genetic syndrome of multiple endocrine neoplasia, some familial pheochromocytomas occur without associated disease. Two patients with familial pheochromocytoma are described. One had an extraadrenal tumor, producing severe renal artery stenosis and in whose family pheochromocytomas were found in three successive generations. A second had multiple pheochromocytomas associated with von Hippel-Lindau disease and a family member with multiple endocrine neoplasia type 2. The combinations and permutations of these genetic entities form discrete syndromes, with other peculiar interrelationships, pathologically related to an aberration in the migration, growth, and differentiation of the neural crest cells, and emphasizing their common neuroectodermal origin. The unique features that characterize the familial pheochromocytomas and cause diagnostic and therapeutic challenges are reviewed.     

Left ventricular growth in a patient with critical coarctation of the aorta and hypoplastic left ventricle

An infant is presented who at birth met criteria consistent with hypoplastic left heart syndrome. He was followed clinically and by 11 weeks of age demonstrated substantial growth of the left ventricle. He underwent successful repair of coarctation of the aorta and continues to do well with moderate aortic stenosis. The difficulties of predicting left ventricular growth and function are discussed, and management options are reviewed.     

Analysis of spleen specimens for carbon monoxide.

Crucial to the investigation of aircraft fatalities is the analysis of biological specimens for carbon monoxide (CO). In many cases, blood specimens are unavailable or unsuitable for analysis, and the testing of an alternate specimen for CO becomes necessary. Spleen specimens provide a rich source of red blood cells and hence can be a primary substitute for blood. To verify this, 40 paired blood and spleen specimens were analyzed for CO by using a gas chromatographic method. Ten specimens with a spleen CO saturation level (sat.) of less than 10% were associated with corresponding blood specimens with CO sat. less than 10%. Fifteen of the 18 spleen specimens with CO sat. greater than 29% were associated with blood specimens with greater than 48% sat. Results were inconclusive when the spleen CO sat. was between 10 and 29%. We concluded that spleen CO sat. can reflect blood CO sat. in certain situations, particularly when spleen CO sat. is high.     

Distribution of isoniazid in an overdose death.

A fatality due to the ingestion of isoniazid, a tuberculostatic agent, is presented. Isoniazid was extracted by a single step extraction procedure, derivatized with trifluoroacetic anhydride, and identified and quantified by gas chromatography/mass spectrometry (GC/MS). The distribution of isoniazid was as follows: heart blood 43 mg/L, subclavian blood 94 mg/L, urine 470 mg/L, bile 900 mg/L, liver 650 mg/Kg, kidney 110 mg/Kg, and stomach contents 4 mg.     

Pitfalls of regional cerebral blood flow analysis in cerebrovascular disease

In 20 patients with unilateral cerebrovascular disease, regional cerebral blood flow (rCBF) was measured by F-18-fluoromethane inhalation and positron emission tomography (PET). The purpose was to study various strategies of rCBF data analysis that are currently used in SPECT and PET. Methods of quantitative data analysis standardize rCBF values relative to an intraindividual reference, and thus create ratios as estimators of rCBF in the ischemic regions-of-interest (ROI). These ratios were compared as well as the absolute rCBF values in the ischemic ROI graphically and by Spearman's rank correlation coefficient (r). The results demonstrated that previously reported methods of data analysis failed to represent rCBF in the ischemic ROI; r values were 0.467, -0.406, -0.453, and 0.329, respectively (N.S.). This failure was due to a more widespread reduction of rCBF even in patients with minimal ischemic deficits. In conclusion, previously reported strategies of rCBF analysis based on intraindividual standardization should not be used in patients with cerebrovascular disease since they may produce misleading results.