What is the Difference Between Adenoma and Polyp

The key difference between adenoma and polyp is that adenoma is a type of polyp that shows a higher probability of turning into cancer, whereas polyp is benign and has the least probability of developing into cancer.

Adenoma and polyp are types of abnormal growths in the body. They are non-cancerous or benign soft tissue tumors that do not spread throughout the body. These are not usually life-threatening; however, if left untreated or undetected for a longer period of time, it may develop into a malignant tumor. Such growths are usually diagnosed through symptoms such as abdominal pain, anemic conditions, bleeding, fatigue, and nausea or vomiting. Gene mutations or genetic diseases are responsible for adenomas and polyps since they form through dividing cells in an unregulated way. Adenomas and polyps are usually found in mucous membranes and glandular organs.

CONTENTS

1. Overview and Key Difference
2. What is an Adenoma 
3. What is a Polyp
4. Similarities – Adenoma and Polyp
5. Adenoma vs Polyp in Tabular Form
6. Summary – Adenoma vs Polyp

What is an Adenoma?

An adenoma is a non-cancerous tumor that grows along the glandular organs. They are also found in mucous membranes. Such glandular organs are the colon, adrenal gland, parathyroid gland, pituitary gland, and salivary gland. They produce and release chemicals that are known as hormones. Adenomas grow in epithelial tissues, which cover organs and glands. They have slow growth. There are different types of adenomas. Some are adrenal adenomas, parathyroid adenomas, pituitary adenomas, and pleomorphic adenomas. However, the majority of the adenomas are non-functional. Therefore, they do not produce hormones. Adenomas that function well tend to produce hormones.

Figure 01:Tubulovillous Adenoma Under Microscope

Adenomas can be characterized into three groups based on their growth. Tubular adenomas grow in a round or oval shape in the most common small adenoma. Villous adenomas grow as a thick cluster, and they are the most common large adenoma. Tubulovillous adenoma, on the other hand, is a mixture of the previous two types. Tubular adenomas are more common and are less likely to be malignant tumors than villous adenomas. Even though adenomas are benign tumors, they can lead to complications. Some adenomas compress surrounding organs and disrupt the production of hormones.

Factors such as age, ethnic background, hereditary gene mutations such as endocrine neoplasia type 1 (MEN1), genetic diseases such as familial adenomatous polyposis (FAP), and gender affect the risk of developing adenomas. Small or early-stage adenomas do not show symptoms. But adenoma symptoms vary depending on its location. Larger adenomas show visible symptoms such as abdominal pain, headache, fatigue, muscle weakness, bleeding, anemia, and vomiting. Imaging tests such as CT scan, MRI scan, and PET scan help in diagnosing adenomas. Biopsies also analyze and confirm the presence of an adenoma. If the adenoma is large or causes health issues, surgeries are carried out to remove adenomas.

What is a Polyp?

A polyp is a growth of a tissue projecting out from a surface of the body. Polyps usually develop on the mucous membranes and are seen in the colon, rectum, ear canal, nose, throat, cervix, uterus, stomach, and bladder. The most common polyps are colon polyps, uterine polyps, cervical polyps, throat polyps, and nasal polyps. They are the abnormal growth of cells, often without a clear cause. They appear as small and flat bumps. There are several types of polyps, and they are adenomatous polyps, hyperplastic polyps, serrated polyps, and inflammatory polyps. The most common type of polyps is hyperplastic polyps.

Figure 02:  Hyperplastic Polyp Under Microscope

Most polyps are benign, but since they have abnormal growth, they may eventually become malignant. Therefore, biopsies help to determine the growth of polyps. They cause polyps to vary based on the location where they grow. A higher chance of developing certain types of polyps is possible due to genetic changes or genetic diseases. Lynch syndrome is an example of a hereditary non-polyposis colorectal cancer.

Inflammations, cysts, tumors, mutations, and excess estrogen also cause polyps. Treatments of polyps depend on the location, size, and whether they are malignant. Imaging tests such as X-rays, ultrasound, and CT scans help to diagnose polyps. Esophagogastroduodenoscopy, endoscopy, biopsies, and colonoscopy also diagnose polyps. Common symptoms of polyps include bleeding, abdominal pain, cold, nausea, fatigue, and anemia.

What are the Similarities Between Adenoma and Polyp?

• Adenoma and polyps are are abnormal growths.
• Both have common symptoms such as bleeding, abdominal pain, nausea, fatigue, and anemia.
• Most are benign but may develop into cancer.
• CT scans and biopsies diagnose adenomas and polyps.
• Genetic mutations and diseases are risk factors for both.

What is the Difference Between Adenoma and Polyp?

Adenomas are a type of polyp that shows a higher probability of turning into cancer, whereas polyps are benign and have the least probability of developing into cancer. Thus, this is the key difference between adenoma and polyp. Adenomas grow along the glandular organs and mucous membranes and are of three types; tubular, villous, and tubulovillous. Polyps grow mostly on mucous membranes and are of mainly five types: adenomatous, hyperplastic, serrated, and inflammatory. Moreover, adenomas are thick, and round-shaped bumps, whereas polyps appear as small and flat bumps.

The below infographic presents the differences between adenoma and polyp in tabular form for side by side comparison.

Summary – Adenoma vs Polyp

Adenoma and polyp are types of abnormal growths in the body. Adenomas show a higher probability of turning into cancer. In contrast, polyps are benign and have the least probability of developing into cancer. Moreover, adenoma is a non-cancerous tumor that grows along glandular organs and in mucous membranes. A polyp is a growth of a tissue projecting out from a surface of the body. Polyps usually develop on the mucous membranes and are seen in the colon, rectum, ear canal, nose, throat, cervix, uterus, stomach, and bladder. So, this summarizes the difference between adenoma and polyp.

Reference:

1. “Adenomas: Types, Causes, Symptoms & Prevention.” Cleveland Clinic
2. Pietrangelo, Ann. “Polyps: Types, Treatments, and Biopsy.” Healthline, Healthline Media.

Image Courtesy:

1. “Tubulovillous adenoma” By Nephron – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Hyperplastic Polyp of the Rectum (14060044206)”  By Ed Uthman from Houston, TX, USA – Hyperplastic Polyp of the Rectum (CC BY 2.0) via Commons Wikimedia

ncG1vNJzZmivp6x7pbXFn5yrnZ6YsqOx07CcnqZemLyue9ahmK1lmah6tbTEZpuinpaav6a6wp5km52krLKmuoyam56mn6Kubq3NnWSpp5yuvXA%3D