Webster's New World Medical Dictionary

leiomyoma
See 
fibroid.
leiomyosarcoma
A malignant tumor that origi-
nates in smooth muscle, the major structural com-
ponent of most hollow internal organs and the walls
of blood vessels. Leiomyosarcoma can occur almost
anywhere in the body but is most frequently found
in the uterus and gastrointestinal tract. Complete
surgical excision, if possible, is the treatment of
choice.
Leishmania
A group of parasites that cause sev-
eral human diseases. See also 
leishmaniasis.
leishmaniasis
A parasitic disease that is spread
by the bite of sand flies infected with the protozoa
Leishmania. There are several forms of leishmania-
sis, the most common being cutaneous and visceral
leishmaniasis (known as kala-azar). The cutaneous
form of the disease causes skin sores and is usually
named for a geographic place (for example, Jericho
boil, Baghdad button, Delhi sore). Visceral leishma-
niasis affects the internal organs of the body and can
be fatal. See also 
kala-azar.
Lemierre’s disease
A rare, potentially lethal
complication of tonsillitis caused by anaerobic (not
requiring oxygen) bacteria including Fusobacteria.
The disease usually develops after a bacterial infec-
tion has created an abscess near the tonsils. Deep in
the abscess, the anaerobic bacteria can flourish.
The bacteria penetrate from the abscess into the
neighboring jugular vein in the neck to cause an
infected blood clot to form and are seeded by the
bloodstream throughout the body. The keys to sur-
vival are prompt recognition of the disease, imme-
diate use of appropriate antibiotics and drainage of
abscesses. Also known as postanginal sepsis.
Lennox syndrome
See 
Lennox-Gastaut
syndrome.