Thoracic Kidney

A 74-year-old man with diabetes and hypertension was referred to the hospital for evaluation of a mass in the right side of the chest, identified on a radiograph (Panel A, arrows). He reported no pulmonary problems and no history of chest trauma. Physical examination was unremarkable. Reformatted coronal (Panel B) and sagittal (Panel C) computed tomographic scans show the right kidney (large arrows) and part of the liver protruding above the diaphragm (small arrows) and into the posteromedial aspect of the right hemithorax through the foramen of Bochdalek (arrowheads indicate the defective fusion of the diaphragm).

Thoracic kidney is a rare congenital anomaly. Because of the location of the liver, thoracic kidney on the right side is much less common than thoracic kidney on the left side. Thoracic kidney is twice as common in men as in women. Typically, the presence of a thoracic kidney is asymptomatic and requires no intervention, as in this case.

Nutcracker phenomenon

It results most commonly from the compression of the left renal vein between the abdominal aorta (AA) and superior mesenteric artery (SMA), although other variants exist. The name derives from the fact that, in the sagittal view, the SMA and AA (with some imagination) appear to be a nutcracker crushing a nut (the renal vein).
There is a wide spectrum of clinical presentations and diagnostic criteria are not well defined resulting in frequently delayed or incorrect diagnosis. This condition is not to be confused with superior mesenteric artery syndrome, which is the compression of the third portion of the duodenum by the SMA and the AA.

This Computed tomography for a 52-year-old woman with mild episodic gross hematuria revealed compression of the left renal vein between the superior mesenteric artery (SMA) and the aorta (Ao) before the vein merges into the inferior vena cava (IVC). This compression caused marked dilatation of the distal part of the renal vein (RV). The renal venous congestion caused hematuria, presumably through the rupture of submucosal veins into the renal pelvis. No treatment was given. Entrapment of the renal vein is a known cause of hematuria.

Canavan Disease Pic

Subcortical spongy changes of the white matter. The cortex above is spared. The dark stained neurons are not affected.

Canavan disease, one of the most common cerebral degenerative diseases of infancy, is a gene-linked, neurological birth disorder in which the white matter of the brain degenerates into spongy tissue riddled with microscopic fluid-filled spaces.
It occurs due to a deficiency of the enzyme called Aspartoacylase, since the gene which usually tells the body to produce this enzyme is faulty. Babies are born apparently unaffected. At 2 to 4 months of age, he/she develops poor head control and seizures.

Renal Failure from Vitamin C after Transplantation

A 31-year-old woman with bilateral nephrectomy due to bleeding angiomyolipomas from tuberous sclerosis received a kidney transplant with good early graft function. Irreversible, oliguric renal allograft failure soon developed from widespread deposition of calcium oxalate crystals, involving 30% of tubules (Panels A and B, hematoxylin and eosin). The patient had abundant oxalate deposits in the skin (resembling tophaceous gout but without hyperuricemia) (Panels C and D); polarizing microscopy confirmed the presence of oxalate in a specimen from these deposits (Panel E).

She had a plasma oxalate level of 62 µmol per liter (normal value, <2) and a history of self-medication with vitamin C (2 g per day for 3 years while on dialysis). A diagnosis of secondary oxalosis was established. Excess ascorbate is normally excreted harmlessly in the urine, but in patients with renal failure, it is retained and converted to insoluble oxalate and can accumulate in multiple organs. High-dose vitamin C therapy should be avoided in patients with renal failure.