Ultrasonography of liver tumors involves two stages: detection and characterization. Tumor detection is based on the performance of the method and should include morphometric information (three axes dimensions, volume) and topographic information (number, location specifying liver segment and lobe/lobes). The specification of these data is important for staging liver tumors and prognosis. Tumor characterization is a complex process based on a sum of criteria leading towards tumor nature definition. Often, other diagnostic procedures, especially interventional ones are no longer necessary. Tumor characterization using the ultrasound method will be based on the following elements: consistency (solid, liquid, mixed), echogenicity, structure appearance (homogeneous or heterogeneous), delineation from adjacent liver parenchyma (capsular, imprecise), elasticity, posterior acoustic enhancement effect, the relation with neighboring organs or structures (displacement, invasion), vasculature (presence and characteristics on Doppler ultrasonography and contrast-enhanced ultrasound (CEUS).

Patients are usually managed by a multidisciplinary team including surgeons, gynecologists, and dermatologists because of the complex nature of this disorder. Follow-up for the increased risk of breast cancer risk includes monthly breast self-examination, annual breast examination, and mammography at age 30 or five years earlier than the youngest age of breast cancer in the family. The magnitude of the risk of breast cancer justifies routine screening with breast MRI as per published guidelines.

The most common method of testing for hepatoblastoma is a blood test checking the alpha-fetoprotein level. Alpha-fetoprotein (AFP) is used as a biomarker to help determine the presence of liver cancer in children. At birth, infants have relatively high levels of AFP, which fall to normal adult levels by the first year of life. The normal level for AFP in children has been reported as lower than 50 nanograms per milliliter (ng/ml) and 10 ng/ml. An AFP level greater than 500 (ng/ml) is a significant indicator of hepatoblastoma. AFP is also used as an indicator of treatment success. If treatments are successful in removing the cancer, the AFP level is expected to return to normal.

Upon discovery of a liver tumor, the main issue in the workup is to determine whether the tumor is benign or malignant. Many imaging modalities are used to aid in the diagnosis of malignant liver tumors. For the most common of these, hepatocellular carcinoma (HCC), these include sonography (ultrasound), computed tomography (CT) and magnetic resonance imaging (MRI). When imaging the liver with ultrasound, a mass greater than 2 cm has more than 95% chance of being HCC. The majority of cholangiocarcimas occur in the hilar region of the liver, and often present as bile duct obstruction. If the cause of obstruction is suspected to be malignant, endoscopic retrograde cholangiopancreatography (ERCP), ultrasound, CT, MRI and magnetic resonance cholangiopancreatography (MRCP) are used.

Tumor markers, chemicals sometimes found in the blood of people with cancer, can be helpful in diagnosing and monitoring the course of liver cancers. High levels of alpha-fetoprotein (AFP) in the blood can be found in many cases of HCC and intrahepatic cholangiocarcinoma. Cholangiocarcinoma can be detected with these commonly used tumor markers: carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125). These tumour markers are found in primary liver cancers, as well as in other cancers and certain other disorders..

In terms of diagnosing Bannayan–Riley–Ruvalcaba syndrome there is no current method outside the physical characteristics that may be present as signs/symptoms. There are, however, multiple molecular genetics tests (and cytogenetic test) to determine Bannayan–Riley–Ruvalcaba syndrome.

There are three methods of scanning that detect angiomyolipoma: ultrasound, CT and MRI. Ultrasound is standard and is particularly sensitive to the fat in angiomyolipoma but less so to the solid components. However it is hard to make accurate measurements with ultrasound, particularly if the angiomyolipoma is near the surface of the kidney (Maclean Grade III). Computed tomography (CT) is very detailed and fast and allows accurate measurement. However, it exposes the patient to radiation and the dangers that a contrast dye used to aid the scanning may itself harm the kidneys. Magnetic resonance imaging (MRI) is safer than CT but many patients (particularly those with the learning difficulties or behavioural problems found in tuberous sclerosis) require sedation or general anaesthesia and the scan cannot be performed quickly. Some other kidney tumours contain fat, so the presence of fat isn't diagnostic. It can be difficult to distinguish a fat-poor angiomyolipoma from a renal cell carcinoma (RCC). Both minimal fat AMLs and 80% of the clear cell type of RCC display signal drop on an out-of-phase (OOP) MRI sequence compared to in-phase (IP). Thus, a lesion growing at greater than 5 mm per year may warrant a biopsy for diagnosis.

Incidental discovery of angiomyolipomas should trigger consideration of tuberous sclerosis complex (TSC) and lymphangioleiomyomatosis, especially if they are large, bilateral and/or multiple. Screening for TSC includes a detailed physical exam, including dermatologic and ophthalmologic evaluations, by TSC expert clinicians and a CT or MRI of the brain. Screening for LAM includes a high resolution CT of the lung and pulmonary function testing.

In terms of treatment/management one should observe what signs or symptoms are present and therefore treat those as there is no other current guideline. The affected individual should be monitored for cancer of:

- Thyroid

- Breast

- Renal

Most juvenile polyps are benign, however, malignancy can occur. The cumulative lifetime risk of colorectal cancer is 39% in patients with juvenile polyposis syndrome.

Because Cowden syndrome can be difficult to diagnose, the exact prevalence is unknown; however, it probably occurs in at least 1 in 200,000 people.

A 2010 review of 211 patients (21 from one center, and the remaining 190 from the external literature) studied the risks for cancer and Lhermitte-Duclos disease in Cowden syndrome patients.

The cumulative lifetime (age 70 years) risks were 89% for any cancer diagnosis (95% confidence interval (CI) = 80%,95%), breast cancer [female] 81% (CI = 66%,90%), LDD 32% (CI = 19%,49%), thyroid cancer 21% (CI = 14%,29%), endometrial cancer 19% (CI = 10%,32%) and renal cancer 15% (CI = 6%,32%). A previously unreported increased lifetime risk for colorectal cancer was identified (16%, CI = 8%,24%). Male CS patients had fewer cancers diagnosed than female patients and often had cancers not classically associated with CS.

People with juvenile polyps may require yearly upper and lower endoscopies with polyp excision and cytology. Their siblings may also need to be screened regularly. Malignant transformation of polyps requires surgical colectomy.

The most common hamartomas occur in the lungs. About 5–8% of all solitary lung nodules, about 75% of all benign lung tumors, are hamartomas. They almost always arise from connective tissue and are generally formed of cartilage, connective tissue, and fat cells, although they may include many other types of cells. The great majority of them form in the connective tissue on the outside of the lungs, although about 10% form deep in the linings of the bronchi. They can be worrisome, especially if situated deep in the lung, as it is sometimes difficult to make the important distinction between a hamartoma and a lung malignancy. An X-ray will often not provide a definitive diagnosis, and even a CT scan may be insufficient if the hamartoma lacks the typical cartilage and fat cells. Lung hamartomas may have popcorn-like calcifications on chest xray or computed tomography (CT scan).

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.

At CT scans, bile duct hamartomas appear as small, well-defined hypo- or isoattenuating masses with little or no enhancement after contrast administration. At MRI, they appear hypointense on T1-weighted images, iso- or slightly hyperintense on T2-weighted images, and hypointense after administration of gadolinium based contrast-agent. On imaging, multiple hamartomas may look similar to metastases or microabscesses.

Surgical removal of the tumor, adjuvant chemotherapy prior to tumor removal, and liver transplantation have been used to treat these cancers. Primary liver transplantation provides high, long term, disease-free survival rate in the range of 80%, in cases of complete tumor removal and adjuvant chemotherapy survival rates approach 100%. The presence of metastases is the strongest predictor of a poor prognosis.

The first sign is normally a painless abdominal tumor that can be easily felt by the doctor. An ultrasound scan, computed tomography scan, or MRI scan is done first. A tumor biopsy is not typically performed due to the risk of creating fragments of cancer tissue and seeding the abdomen with malignant cells.

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.

Stage V Wilms tumor is defined as bilateral renal involvement at the time of initial diagnosis.

Note: For patients with bilateral involvement, an attempt should be made to stage each side according to the above criteria (stage I to III) on the basis of extent of disease prior to biopsy.

A bile duct hamartoma or biliary hamartoma, is a benign tumour-like malformation

of the liver.

They are classically associated with polycystic liver disease, as may be seen in the context of polycystic kidney disease, and represent a malformation of the liver plate.

Treatment is varied and depends on the site and extent of tumor involvement, site(s) of metastasis, and specific individual factors. Surgical resection, radiotherapy, and chemotherapy have all been used to treat these masses, although studies on survival have yet to be conducted to delineate various treatment regimens.

Choristomas, forms of heterotopia, are closely related benign tumors, found in abnormal locations.

It is different from hamartoma. The two can be differentiated as follows: a hamartoma is disorganized overgrowth of tissues in their normal location, (eg, Peutz-Jeghers polyps) while a choristoma is normal tissue growth in an abnormal location (e.g., gastric tissue located in distal ileum in Meckel diverticulum).

Small angiomyolipomas and those without dilated blood vessels (aneurysms) cause few problems, but angiomyolipomas have been known to grow as rapidly as 4 cm in one year. An angiomyolipoma larger than 5 cm and those containing an aneurysm pose a significant risk of rupture, which is a medical emergency as it is potentially life-threatening. One population study found the cumulative risk of haemorrhage to be 10% in males and 20% in females.

A second problem occurs when the renal angiomyolipomas take over so much kidney that the function is impaired leading to chronic kidney disease. This may be severe enough to require dialysis. A population survey of patients with TSC and normal intelligence found 1% were on dialysis.

Microscopical examination shows abundant thin-walled blood vessels with hypocellular and hypercellular areas.

Treatment is not needed in the asymptomatic patient. Symptomatic patients may benefit from surgical debulking of the tumor. Complete tumor removal is not usually needed and can be difficult due to the tumor location.

Doege–Potter syndrome (DPS) is a paraneoplastic syndrome in which hypoglycemia is associated with solitary fibrous tumors. The hypoglycemia is the result of the tumors producing insulin-like growth factor 2. The syndrome was first described in 1930, by Karl Walter Doege (1867–1932), a German-American physician and by Roy Pilling Potter (1879–1968), an American radiologist, working independently; the full term "Doege–Potter syndrome" was infrequently used until the publication of a 2000 article using the eponym.

DPS is rare (as of 1976, less than one hundred cases were described), with a malignancy rate of 12–15%. Actual rates of hypoglycemia associated with a fibrous tumor are quite rare (a 1981 study of 360 solitary fibrous tumors of the lungs found that only 4% caused hypoglycemia), and are linked to large tumors with high rates of mitosis. Removal of the tumor will normally resolve the symptoms.

Tumors causing DPS tend to be quite large; in one case a , mass was removed, sufficiently large to cause a collapsed lung. In X-rays, they appear as a single mass with visible, defined borders, appearing at the edges of the lungs or a fissure dividing the lobes of the lungs. Similar hypoglycemic effects have been related to mesenchymal tumors.

2004 research showed that CCSK patients exhibit an improved relapse-free survival from a longer course of therapy when using vincristine, doxorubicin, and dactinomycin, but their long-term survival is unchanged compared with patients receiving 6 months of therapy.

Lhermitte–Duclos disease is a rare entity; approximately 222 cases of LDD have been reported in medical literature. Symptoms of the disease most commonly manifest in the third and fourth decades of life, although it may onset at any age. Men and women are equally affected, and there is not any apparent geographical pattern.