Differentiate between main and cavity

Difference Between Cyst and Polyp

Key difference - cyst versus polyp

A polyp is a mass that grows over a mucosal surface and forms a macroscopically visible structure. A cyst is a lump that consists of an epithelial-lined cavity that is filled with a fluid or semi-solid material. The main difference between cyst and polyp is as follows Cysts have a fluid-filled cavity, while polyps do not have fluid-filled cavities. It is important to clearly understand the difference between a cyst and a polyp in order to manage and manage these conditions.

1. Overview and main difference
2. What is a polyp?
3. What is a cyst?
4. Side by side comparison - cyst versus polyp in tabular form
5. Summary

What is a polyp

A mass that grows over a mucosal surface and forms a macroscopically visible structure is called a polyp. These are usually attached to the mucous membrane by a distinct stalk.

In most cases, polyps are benign tumors, but malignant polyps can also occur. Inflammatory polyps like those seen in the nasal mucosa are not neoplastic.

Colorectal polyps

An abnormal growth of tissue that protrudes from the lining of the colon is called a colon polyp. These polyps can be either single or multiple, and they can be found in various forms, such as:

  • Pedunculate polyps
  • Flat polyps
  • Sessile polyps

The diameter of a polyp can vary from a few millimeters to several centimeters.

Colorectal polyps have been classified into various categories such as adenoma, hamartoma, etc. according to their histological features.

Pathological conditions related to the formation of colorectal polyps:

  1. Sporadic adenomas

Adenoma is the precursor lesion of colon cancer. Initially, they appear as benign tumors, but with the appearance of dysplastic changes, they can become malignant.

The risk of malignant transformation is high if the colon polyp,

  • Is more than 1.5 cm in diameter,
  • Is multiple, sitting or flat,
  • Has severe dysplasia with villous architecture and associated squamous cell metaplasia.

If the risk of malignant transformation is high, a colonoscopy is done to remove the tumors from the intestine. Continuous monitoring is required even after their removal.

Rectal bleeding is the most commonly observed clinical feature of polyps in the rectum and sigmoid colon. Proximal lesions are usually asymptomatic.

  1. Sessile jagged adenoma

This category includes benign hyperplastic polyps (HPS), traditional jagged adenomas (TSA), and premalignant sessile jagged adenomas (SSA). These lesions differ from the others due to the sawtooth appearance of the epithelial layer. Endoscopic resection of SSAs and TSAs is recommended.

3. Colorectal cancer

Colorectal cancer is the third most common cancer in the world.

Clinical features of the disease are:

  • Loose chairs
  • Rectal bleeding
  • Symptoms of anemia
  • Tenesmus
  • Palpable rectal or abdominal mass

The following tests are done to rule out the possibility of colorectal cancer

  • Colonoscopy - the gold standard
    • Endoanal ultrasound and pelvic MRI
    • Double contrast barium enema

Multidisciplinary team participation is required for treatment of the disease. Surgical resection of the affected bowel region is performed in most patients. Surgical intervention varies depending on the location of the cancer, and the prognosis for the disease depends on the stage and presence of metastases.

Gallbladder polyps

Gallbladder polyp is a common finding in patients referred for hepatobiliary ultrasonography. These polyps are inflammatory and contain deposits of cholesterol. Most of them are small and benign. There can also be malicious ones. If the size of the polyps is more than 10 cm, then they can be cancerous. Cholecystectomy is the recommended treatment for this.

Gastric polyps

This disease is relatively rare and asymptomatic most of the time. Larger lesions can lead to hematemesis or anemia. The diagnosis of the lesion can be made endoscopically. A polypectomy can be done depending on the histology of the polyp. Surgical intervention is required if large or multiple polyps are present.

nasal Polyps

These polyps are round, smooth, soft, semi-transparent, pale structures that are attached to the nasal mucosa by a narrow stalk. They usually occur in people with allergic or vasomotor rhinitis. Mast cells, eosinophils and mononuclear cells are found in large numbers. Nasal polyps can cause nasal congestion, loss of taste and smell, and mouth breathing. Intranasal steroids are used to treat this condition.

What is a cyst?

A lump consisting of an epithelial-lined cavity filled with fluid or semi-solid material is called a cyst. Most of the cysts we encounter are translucent, lined with a gray, shiny, smooth membrane, and filled with a clear fluid. Cysts occur in different organs such as the liver, kidneys, and lungs for a variety of pathological reasons. Some of the cysts that can appear in the human body are:

  • Hydatid cyst
  • Cystic kidney disease
  • Fibrocystic liver disease
  • Lung cysts
  • Biliary cysts
  • Baker's cyst
  • Sebum cyst
  • Pilar cyst

Hydatid cysts

Hydatid cysts are formed in hydatid disease, in which humans become intermediate hosts of the dog tapeworm. Echinococcus granulosus. The adult worm lives in the intestines of domestic and wild dogs. Humans become infected through direct contact with dogs or through food or water contaminated with dog feces. After ingestion, the worm exocyst penetrates the intestinal wall and reaches the liver and other organs via the blood. A thick-walled, slow-growing cyst forms. Within this cyst, further development of the larval stages of the parasite takes place. The liver is the most common organ affected by this condition. The most commonly observed clinical manifestations are:

  • Jaundice (due to pressure on the bile duct)
  • stomach pain
  • Fever associated with eosinophilia
  • Sputum (due to a ruptured cyst in the bronchus)
  • Chronic lung abscess
  • Focal seizures (due to cysts in the brain)
  • Lumbar pain and hematuria

Examination may show peripheral eosinophilicity and a positive hydatide complement fixation test. Calcification of the outer covering of the cyst can be seen on an x-ray of the abdomen.


  • Albendazole 10 mg / kg can reduce the size of the cyst.
  • Puncture, aspiration, injection, reaspiration (PAIR) can be performed
  • The fine needle aspiration takes place under ultrasound guidance

Cystic kidney disease

Cystic kidney disease is an inherited, developmental, or acquired condition. Various forms of cystic kidney disease are listed below.

  • Polycystic Disease in Adults
  • Polycystic disease in childhood (autosomal recessive)
  • Single cysts
  • Medullary diseases with cysts

Fibrocystic Diseases of the Liver

These disorders can lead to liver cysts or fibrosis. Polycystic liver disease occurs as part of polycystic kidney disease. Hepatic fibrocystic disease is usually asymptomatic, but can occasionally cause abdominal pain and gas.

What is the difference between cyst and polyp?

Cyst versus polyp

A cyst is a lump that consists of an epithelial-lined cavity filled with fluid or semi-solid material.A polyp is a mass that grows over a mucosal surface and forms a macroscopically visible structure.
Cavities filled with liquid
Cysts have a cavity filled with fluid.Polyps do not have fluid-filled cavities.

Summary - cyst versus polyp

As discussed at the beginning, a cyst is a nodule consisting of an epithelial-lined cavity filled with fluid or semi-solid material, and a polyp is a mass that grows over a mucosal surface and forms a macroscopically visible structure. Thus, the difference between a cyst and a polyp is the presence of fluid-filled cavities. The clear identification of each disease is important for the treatment of the patient.

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1. Gawkrodger, David. Dermatology. No: Churchill Livingstone, 2007. Print.
2. Kumar, Parveen J., and Michael L. Clark. Kumar & Clark clinical medicine. Edinburgh: W.B. Saunders, 2009. Print.
3. Kumar, Vinay, Stanley Leonard Robbins, Ramzi S. Cotran, Abul K. Abbas and Nelson Fausto. Robbins and Cotran pathological basis of the disease. 9th ed. Philadelphia, PA: Elsevier Saunders, 2010. Print

Image courtesy:

1. "Bronchogenic Cyst High Mag" by Nephron - Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Uterine polyps” by BruceBlaus - Own work (CC BY-SA 4.0) via Commons Wikimedia