Dr. Lee was born in Shanghai, China, and received his college and medical training in the United States. He is fluent in English and three Chinese dialects. He graduated with chemistry departmental honors from Harvey Mudd College. He was appointed president of AOA society at UCLA School of Medicine. He underwent internal medicine residency and gastroenterology fellowship training at Cedars Sinai Medical Center.
Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
The prevalence of carcinoid tumors is difficult to
determine since many carcinoid tumors are not detected because they produce no
symptoms. In one autopsy series, carcinoid tumors were estimated to have a
prevalence of 8/100,000 people annually, but 90% of the carcinoids found at
autopsy were not the cause of death.
The carcinoid syndrome is very rare. This is because
many carcinoid tumors do not produce hormones. Another reason that the syndrome
is rare is that hormones released by carcinoid tumors, particularly from tumors
within the abdomen, often are destroyed by the liver before they reach the
general circulation to cause
symptoms. For example, hormones produced by small intestinal carcinoid tumors
are released into the portal vein. The portal
vein blood passes through the
liver before reaching the heart and the general circulation. As the portal vein
blood passes through the liver, the hormones are destroyed by the liver.
Only those carcinoid tumors that can release hormones
directly into the general circulation (and not into the portal veins which pass
through the liver) can produce the carcinoid syndrome. Thus, the most common
cause of carcinoid syndrome is small intestinal carcinoid tumors that have
metastasized to the liver. The metastases in the liver can release hormones
directly into the circulation. Another rare example is carcinoid tumors of the
bronchial airways. Carcinoid tumors in the bronchial airways can release
hormones directly into the general circulation via the pulmonary veins without passing through the liver.
Carcinoid tumors can be benign (non-cancerous) or
malignant (cancerous). Benign carcinoid tumors are typically small (less than 1
cm). They usually can be removed completely and, in most cases, they do not come
back. Cells from benign carcinoid tumors do not spread to other parts of the
body. Benign carcinoid tumors typically produce no symptoms and are commonly
found by chance during flexible sigmoidoscopy or upper gastrointestinal
endoscopy.
Cancerous carcinoid tumors are typically large (larger
than 2 cm) at the time of diagnosis. Cells from these malignant tumors can invade and damage tissues
and organs near the tumor. Moreover, malignant cells can break away and enter
the bloodstream or lymphatic system and
spread to form new tumors in other parts of the body. (The distant tumors are
called metastases.) Common sites for carcinoid metastases include the lymph
nodes, liver, lung, bone, and skin.
Carcinoid tumors between 1.0 and 2.0 cm in size have approximately a 10%
chance of being cancerous at the time of diagnosis.
Carcinoid tumors are typically slow growing. They grow
much more slowly than other cancers such as colon, pancreas, liver, and lung
cancer. Many small carcinoid tumors produce no symptoms and are not fatal; they
are found incidentally at autopsy. Even patients with larger, malignant
carcinoid tumors (with or without metastasis) can survive years or decades with
a good quality of life. This is especially true with modern treatments to
control the carcinoid syndrome and to control the growth of the carcinoid
tumors. However, there is a rare form of carcinoid tumor called adenocarcinoids
that are more aggressive
than the typical malignant carcinoid tumor, and they have a poor prognosis. An
experienced pathologist can
identify adenocarcinoid tumors by examining the tissue from the tumor under a
microscope.
Abdominal pain is pain in the belly and can be acute or chronic. Causes include inflammation, distention of an organ, and loss of the blood supply to an organ. Abdominal pain can reflect a major problem with one of the organs in the abdomen such as the appendix, gallbladder, large and small intestine, pancreas, liver, colon, duodenum, and spleen.
Diarrhea is a change is the frequency and looseness of bowel movements. Cramping, abdominal pain, and the sensation of rectal urgency are all symptoms of diarrhea. Absorbents and anti-motility medications are used to treat diarrhea.
Night sweats are severe hot flashes that occur at night and result in a drenching sweat. In order to distinguish night sweats that arise from medical causes from those that occur because one's surroundings are too warm, doctors generally refer to true night sweats as severe hot flashes occurring at night that can drench sleepwear and sheets, which are not related to an overheated environment.
Hot flashes (or flushing) is the most common symptom experienced by a woman prior to and during the early stages of menopause. Hot flashes can be caused by other conditions. Diagnosis is made by taking a patient history and at times, blood tests. Treatment options include hormone therapy, bioidentical hormone therapy, and medications. There are non-FDA approved natural remedies.
Heart valve disease occurs when the heart valves do not work the way they should. Symptoms of valve disease include shortness of breath, weakness or dizziness, discomfort in your chest, palpitations, swelling of your ankles, feet or abdomen, and rapid weight gain.
Digestion RSS
Healthy Living Tips
This site complies with the