Items tagged “variant”

Occipital vertebrae are rare anatomical variants that result from incomplete or aberrant fusion of occipital bone ossification centers. There is a broad spectrum of occipital vertebrae, the more common variants include: third condyle (condylus tertius) basilar process prebasioccipital arch p...

Abnormal renal rotation, also known as renal malrotation, refers to an anatomical variation in the position of the kidneys, in particular to anomalous orientation of the renal hilum. It may occur unilaterally or bilaterally. It is almost always an asymptomatic incidental finding. Epidemiology ...

An intrathoracic kidney is a very rare form of ectopic kidney. There has been no reported increased incidence of stones or infections as can be seen with other forms of ectopic kidneys. The adrenal glands are usually normal in location in most cases. Epidemiology Thoracic ectopic kidney is rar...

The supraclavicular foramen is a normal variant and typically found as an incidental finding on radiographs. It occurs in ~4% (range 2-6%) of the population.  Supraclavicular foramen appear as an osseous tunnel or tunnels, with the most typical position at the superior aspect of the junction of...

Polyorchidism, also known as supernumerary testes, refers to the presence of more than two testes and is a very rare congenital anomaly. The supernumerary testis can be usually located inside the scrotum (75% of the patients) or less commonly in the inguinal canal, the retroperitoneum, or the ab...

The superior accessory fissure is present in around 5% of individuals examined with CT 4 and PA chest X-rays 5. Gross anatomy The superior accessory fissure of the right lower lobe is located in the same plane and posterior to the right transverse (minor) fissure. It separates the right lower ...

Crossed renal ectopia is said to be present when the kidney is seen in the opposite retroperitoneal space. It is more common for the left kidney to be ectopically located on the right side. More than 85% of these get fused resulting in crossed fused renal ectopia. Less than 15% cases are non-fus...