A malignant tumor that originates in smooth muscle, the major structural component 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 infection
Mexico, Central America, and South America — from northern Argentina to southern Texas (not in Uruguay, Chile, or Canada) Southern Europe (leishmaniasis is not common in travelers to southern Europe) Asia (not Southeast Asia) The Middle East Africa (particularly East and North Africa, with some cases elsewhere) More than 90% of the world’s visceral leishmaniasis […]
A parasitic disease that is spread by the bite of sand flies infected with the protozoa Leishmania. There are several forms of leishmaniasis, 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, […]
- Lemierre syndrome
A potentially lethal form of sore throat caused by the bacterium Fusobacterium necrophorum, a common inhabitant of the mouth. This disease vanished with the advent of antibiotics but then returned decades later. It has been called the “forgotten disease.” Lemierre syndrome develops most often after a strep sore throat has created a peritonsillar abscess, a […]
- Lennox syndrome
A severe form of epilepsy that is characterized by the onset in early childhood of frequent seizures of multiple types, developmental delay, a particular brain wave pattern (a slow spike-and-wave pattern), and behavioral disturbances with poor social skills and attention-seeking behavior. The types of seizures may include tonic (stiffening of the body, upward deviation of […]
- Lennox-Gastaut syndrome
A severe form of epilepsy that usually begins in early childhood. It is characterized by frequent seizures of multiple types, mental impairment, and a slow spike-and-wave pattern seen on an EEG. The seizures are notoriously hard to treat and may lead to falls and injuries. Treatment involves anti-epileptic medications.