Webster's New World Medical Dictionary

tuberculosis, MDR
Multi-drug-resistant tuber-
culosis. See 
tuberculosis, antibiotic-resistant.
tuberculosis, miliary
The presence of numer-
ous sites of tuberculosis (TB) infection, each of
which is minute. Miliary TB is caused by dissemina-
tion of infected material through the bloodstream.
tuberculosis, pulmonary
Tuberculosis (TB) in
the lungs. Pulmonary TB is the most common form
of active tuberculosis. It can be easily transmitted to
others when someone who has it coughs.
tuberculosis vaccination
A vaccination for
tuberculosis (TB). The vaccine, known as BCG
(bacille Calmette Guérin), is used in most develop-
ing countries to reduce the severe consequences of
TB in infants and children. However, BCG vaccine
has variable efficacy in preventing adult forms of TB
and is, therefore, not routinely recommended for
use in the US and other developed countries. See
also 
BCG.
tuberculous diskitis
A tuberculosis infection of
the spine that is seen most often in children. The
main symptom is back pain. Untreated tuberculous
diskitis can lead to inward or outward curvature of
the spine. Imaging of the spine can find abscesses,
some of which may have ossified (hardened). Also
known as Pott’s disease. Treatment involves antibi-
otics for extended periods.
tuberous sclerosis
A genetic disorder that is
characterized by abnormalities of the skin, brain,
kidney, and heart. Skin abnormalities are present in
all cases of tuberous sclerosis. They include tiny
benign tumors (angiofibromas) on the face and
depigmented areas anywhere on the body. The brain
abnormalities of tuberous sclerosis are mainly
benign cortical tumors (tubers) that cause seizures,
developmental delay, and mental retardation. The
kidneys in a person with tuberous sclerosis often
contain multiple cysts and benign tumors (angiomy-
olipomas). The heart problems of tuberous sclero-
sis include arrhythmias and benign heart muscle
tumors (rhabdomyomas). Diagnosis is made via
clinical observation, for example, in a child with a
seizure disorder who has white spots on the skin
that are most easily seen under ultraviolet light.
Tuberous sclerosis is inherited in an autosomal
dominant manner and results from mutation of
either one of two genes: the TSC1 gene on chromo-
some 9 or the TSC2 gene on chromosome 16. TSC1
and TSC2 encode products called hamartin and
tuberin, respectively, which act as tumor suppres-
sors. Two-thirds of cases of tuberous sclerosis are
due to new mutations, and the other one-third are
inherited from parents.