Wackenheims line (also known as the clivus canal line or basilar line) is formed by drawing a line along the clivus and extending it inferiorly to the upper cervical canal.
Normally the tip of the dens is ventral and tangential to this line. In basilar invagination odontoid process transects th...
Waldeyer's ring is a ring of lymphoid tissue located in the nasopharynx and oropharynx at the entrance to the aerodigestive tract.
The structures composing this ring are:
palatine tonsils (also called the faucial tonsils)
adenoid tonsils (nasopharyngeal tonsils)
the lateral ba...
Warthin tumours (or papillary cystadenoma lymphomatosum) are benign, sharply demarcated tumours of the salivary gland. They are of lymphoid origin and most commonly arise from parotid gland tail. They may be bilateral or multifocal in up to 20% of cases and are the most common neoplastic cause o...
Widening of diploic space refers to diffuse, most commonly bilateral, calvarium widening secondary to extramedullary hematopoiesis within the skull.
Most commonly caused by systemic underlying pathologies such as:
chronic haemolytic disorders: may be associated with vertical striations...
Widow's peak hair anomaly refers to a frontal hairline projection.
Prominent V shaped hairline projection. Ocular hypertelorism might be noted. On examination a bony prominence may be present.
It is purported that the periorbital fields of hairless region or hairg...
Williams syndrome (WS) is characterised by some or all or the following features:
craniofacial dysmorphism (e.g. elfin facies)
short stature (50% of cases)
mild to moderate mental retardation
supravalvular aortic stenosis 2
pulmonary artery stenosis 3
Wolff-Chaikoff effect is an autoregulatory phenomenon, whereby a large amount of ingested iodine acutely inhibits thyroid hormone synthesis within the follicular cells, irrespective of the serum level of thyroid-stimulating hormone (TSH) 1.
The Wolff-Chaikoff effect is thought to be...
Wormian bones are a subset of the small intrasutural bones that lie between the cranial sutures formed by the bones of the skull vault. The title Wormian bones is reserved for abnormal intrasutural bones that are typically found around the lambdoid suture.
Some consider them abnormal only if gr...