Desmoid Tumor Diagnosis

Executive Summary

Different tests are available to diagnose the development of desmoid tumors, which depends on signs and symptoms, age and health status, types of tumor, and earlier medical tests. Physical examination, imaging tests, and biopsies are the common diagnostic approaches for detecting desmoid tumors development. There are no standard screening procedures for detecting desmoid tumors. Hence doctors use different diagnostic methods to arrive at the appropriate result. Physical examination includes a check for unusual growth, lumps or bumps. The imaging tests include Computed tomography (CT) scan, Magnetic Resonance Imaging (MRI), and ultrasound. Tissue testing of desmoid tumor is performed by doing laboratory tests to analyze the tissue sample and identify specific proteins, genes, or other factors that can indicate tumor growth in the suspected area. Beta-catenin (CTNNB1) gene mutation means that the patient acquired the mutation during their lifetime and is not inherited. Laboratory test analyzes Inherited variations in adenomatous polyposis coli (APC) gene that helps in helping detect and confirm desmoid tumors.

Diagnosis of Desmoid Tumor

Desmoid tumor is a rare disease condition. Doctors use various tests and scans to detect and examine these tumors. They use physical examination, imaging tests, and conduct biopsies to diagnose the disease. Some tests help the doctors learn the size of the tumor and its gravity of growth. Imaging tests can be used to detect whether the tumor has metastasized to nearby tissues or organs. Diagnosis of desmoid tumor is extremely important to decide the best treatment plan to treat and manage the disease ^​1​. 

A biopsy is a sure shot way to diagnose desmoid tumors. Hence doctors use the method widely to identify the presence of tumors in the body. In most cases, biopsy gives a clear result regarding tumor, and there is only a minimal chance that the method may not provide a definite diagnosis. 

The doctor or healthcare team will consider several factors before choosing the diagnostic procedure for a patient’s tumor condition. They include:

• The tumor location
• tumor Size
• Signs and symptoms experienced
• Patient’s age and overall health
• Past medical history and results of medical tests

There are no standard screening procedures for detecting desmoid tumors. Hence doctors use different diagnostic methods to arrive at the apt result. The doctor will examine the patient for abnormal lumps, bumps or growth (usually larger than 2 inches). Usually, desmoid tumors have no symptoms and grow in the body for months or years until diagnosed. Sometimes the tumor may be found when people undergo imaging tests for other health concerns. If you suspect a desmoid tumor growth in your body, don’t hesitate to approach the doctor and get a proper diagnosis and treatment. 

Doctors usually combine clinical examination and imaging tests to diagnose desmoid tumors. The desmoid tumor diagnosis is confirmed via a biopsy. The following are the diagnostic procedures used to detect desmoid tumors:

PHYSICAL EXAMINATION 

The doctor will examine your body to check for unusual growth, lumps or bumps. Physical examinations help your doctor better understand your symptoms and signs.

IMAGING TESTS

The doctor may recommend imaging tests like CT scans or MRI for desmoid tumor diagnosis any suspected tumor growth ^​2​. Imaging tests provide precise results, which will eventually help in treatment and cure.

• Computed tomography (CT or CAT) scan: 

CT scans use X-rays to capture images of the body interior from different angles. A computer then combines these images into detailed three-dimensional pictures that portray abnormal growth. CT scans can also be used to measure tumor size. Sometimes a special dye called a contrast medium is given to the patient either through the vein or as a pill or liquid before the imaging procedure. A contrast medium is widely used to examine intra-abdominal tumor growths. 

• Magnetic resonance imaging (MRI): 

An MRI scan uses magnetic fields instead of x-rays to capture and produce detailed images of the body interior. MRI scans can also measure the size of the tumor. A dye called a contrast medium is given to the patient before the scan to capture clear pictures. The dye is usually administered intravenously. MRI is the imaging test widely used to examine tumor growths in the abdominal wall. The imaging procedure is also used to look for the recurrence of the tumor post-surgery.

• Ultrasound:

Ultrasound is an imaging test that uses sound waves to produce body images. It is widely used to check for any lumps or bumps present under the skin or other structures in the body.

A radiologist will examine the pictures captured via these imaging tests to determine whether the tumor is desmoid. People should ensure that an experienced radiologist reviews the image reports. If possible, make arrangements such that the same radiologist will examine all your future tests and scans to ensure that tumor measurements are consistent and steady. Usually, a biopsy is carried out after imaging tests to confirm the desmoid tumor diagnosis.

BIOPSY

A biopsy refers to removing a tiny sample of tissue from the suspected area to be examined under a microscope. A biopsy always gives a reliable diagnosis; hence, doctors widely prefer it to detect tumors or abnormal growth. The collected sample is evaluated in the laboratory by a trained pathologist (a specialist in analyzing body tissues and detecting diseases or abnormalities). They assess the cells, tissues and organs to detect diseases. The results of the biopsy are extremely vital in designing the treatment strategy ^​3​. 

Since desmoid tumors are rare and there is a high possibility that the tumor can be misdiagnosed, an expert, well-experienced sarcoma pathologist should analyze the tissue sample to produce accurate results. Proper diagnosis of desmoid tumor growth is essential for treating it. Some special tests may be required to detect desmoid tumors. It would be best to carry these tests out by an expert familiar with this tumor condition.

Biopsies could be of different types. The type that is chosen depends on the tumor location. In a needle biopsy, the doctor extracts a tiny tissue sample from the suspected growth using a needle-like instrument. Fine needle aspirations are not usually recommended as they do not detect desmoid tumors effectively. Imaging tests like CT scans, MRIs or ultrasound can guide the needle into the tumor accurately. Another type of biopsy is carried out via surgery. It can be called an incisional biopsy. In an incisional biopsy, the surgeon removes the entire tumor growth.

Desmoid tumors are known for recurring back in the body even after successful treatment and surgery; hence patients are encouraged to talk with their doctor to understand the risks and benefits of such biopsy procedures. Also, before carrying out any surgical procedure or biopsy, the patients must consult a desmoid tumor specialist.

Tissue testing of desmoid tumor:

The doctor may recommend various laboratory tests to analyze the tissue sample and identify specific proteins, genes or other factors that can indicate the possibility of tumor growth in the suspected area. Beta-catenin (CTNNB1) gene mutation occurs in almost 85% of desmoid tumor cases that are sporadic. This indicates that the patient acquired the mutation during their lifetime and is not inherited ^​4​. 10 to 15% of sporadic desmoid tumor cases are caused by an adenomatous polyposis coli (APC) gene mutation. Inherited variations in the APC gene can cause desmoid tumors that are associated with FAP. Laboratory tests that analyze such mutations in genes can help detect and confirm desmoid tumors, which will ultimately help treat the disease.

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