Unlike most such growths, a hypothalamic hamartoma is symptomatic; it most often causes gelastic seizures, and can cause visual problems, other seizures, rage disorders associated with hypothalamic diseases, and early onset of puberty. The symptoms typically begin in early infancy and are progressive, often into general cognitive and/or functional disability. Moreover, resection is usually difficult, as the growths are generally adjacent to, or even intertwined with, the optic nerve. Symptoms tend to be resistant to medical control; however, surgical techniques are improving and can result in immense improvement of prognosis. Kidneys, stomach, spleen and other vascular organs
One general danger of hamartomas is that they may impinge into blood vessels, resulting in a risk of serious bleeding. Because a hamartoma typically lacks elastic tissue, it may lead to the formation of aneurysms and thus possible hemorrhage. Where a hamartoma impinges into a major blood vessel, such as the renal artery, hemorrhage must be considered life-threatening. Angiomyolipoma of the kidney was previously considered to be a hamartoma or choristoma. A myoepithelial hamartoma, also known as a pancreatic rest, is ectopic pancreatic tissue found in the stomach, duodenum, or proximal jejunum. When seen on upper gastrointestinal series, a pancreatic rest may appear to be a submucosal mass or gastric neoplasm. Most are asymptomatic, but they can cause dyspepsia or upper gastrointestinal bleeding.A hamartoma has been identified as a cause of partial outflow obstruction in the abomasum (true gastric stomach) of a dairy goat.Hamartomas of the spleen are uncommon but can be dangerous.
Lung hamartomas are more common in men than in women, and may present additional difficulties in smokers. Some lung hamartomas can compress surrounding lung tissue to a degree, but this is generally not debilitating and is often asymptomatic, especially for the more common peripheral growths. They are treated, if at all, by surgical resection, with an excellent prognosis: generally, the only real danger is the inherent possibility of surgical complications. Heart
Cardiac rhabdomyomas are hamartomas composed of altered cardiac myocytes that contain large vacuoles and glycogen. They are the most common tumor of the heart in children and infants. There is a strong association between cardiac rhabdomyomas and tuberous sclerosis (characterized by hamartomas of the central nervous system, kidneys, and skin, as well as pancreatic cysts); 25-50% of patients with cardiac rhabdomyomas will have tuberous sclerosis, and up to 100% of patients with tuberous sclerosis will have cardiac masses by echocardiography. Symptoms depend on the size of the tumor, its location relative to the conduction system, and whether or not it obstructs blood flow. Symptoms are usually from congestive heart failure; in utero heart failure may occur. If patients survive infancy, their tumors may regress spontaneously; resection in symptomatic patients has good results. Nerves
Sometimes nerves can also be affected. The most common nerve to be affected by hamartoma is reported to be median nerve. Hypothalamus
One of the most troublesome hamartomas occurs on the hypothalamus.