Benign Epithelial Tumors

 

A tumor is an abnormal growth of cells that serves no purpose. A benign tumor is not a malignant tumor, which is cancer. It does not invade nearby tissue or spread to other parts of the body the way cancer can. In most cases, the outlook with benign tumors is very good. But benign tumors can be serious if they press on vital structures such as blood vessels or nerves. Therefore, sometimes they require treatment and other times they do not.

These are limited circumscribed tumors that do not metastasize into other regions of the body, do not recur after resection, and do not have a fatal outcome Most benign tumors are not harmful, and they are unlikely to affect other parts of the body. However, they can cause pain or other problems if they press against nerves or blood vessels or if they trigger the overproduction of hormones, as in the endocrine system [1, 2].

Examples of benign tumors include [2]:

Adenomas

Adenomas develop in glandular epithelial tissue, which is the thin membrane that covers glands, organs, and other structures in the body.

Examples include:

• polyps in the colon
• fibroadenomas, a common form of benign breast tumor
• hepatic adenomas, which occur on the liver

Adenomas do not start as cancer. However, some can change and become adenocarcinomas, which are cancerous.

Learn more about fibroadenomas of the breast here.

Fibroids

Fibroids, or fibromas, are benign tumors that can grow on the fibrous or connective tissue of any organ. Uterine fibroids are common and can cause:

• vaginal bleeding
• pelvic pain or discomfort
• urinary incontinence

They can be “soft” or “hard,” depending on the proportion of fibers to cells. There are many types of fibroma, including:

• angiofibromas, which can appear as small red bumps on the face
• dermatofibromas, which appear on the skin, often on the lower legs

Some fibromas can cause symptoms and may need surgery. In rare cases, fibroids can change and become fibrosarcomas. These are cancerous.

Hemangiomas

Hemangiomas are benign tumors that form when blood vessels grow excessively. They can appear as red “strawberry marks” on the skin or they can develop inside the body. They are often present at birth and disappear during childhood. Hemangiomas do not usually need treatment, but laser surgery and other options are available if they do not go away.

Lipomas

Share on PinterestLipomas are most common in people from 40–60 years old.

Lipomas are a form of soft tissue tumor and consist of fat cells. They can appear at any age but often affect people from 40–60 years old, according to the American Academy of Orthopaedic Surgeons (AAOS).

Most lipomas are small, painless, rubbery, soft to the touch, and movable. They often appear on the back, shoulders, arms, buttocks, and the tops of the legs.

The AAOS note that they are unlikely to become cancerous.

Types of lipoma include fibrolipomas, which contain fat cells and fibrous connective tissue, and angiolipomas, which appear under the skin [3].

Benign tumors can be subdivided into four categories: epithelial, mesenchymal, salivary gland tumors, and cysts of soft tissue. Although soft tissue cysts are not tumors, their historical and clinical features resemble those of benign tumors. Each of these categories is further subclassified as shown in Tables 1 [4].

  Table 1Benign Epithelial Tumors.

BENIGN EPITHELIAL TUMORS Firm; non-tender; fixed to the surface; rough or cauliflower surface; pale.
Papilloma	Pedunculated; exophytic
Verruca vulgaris	Broad-based; exophytic
Condyloma acuminatum	Broad-based; exophytic; multiple lesions; frequently genital lesions

 

Causes

Causes of Benign tumors are mostly linked to [5]:

• Environmental toxins, such as exposure to radiation
• Genetics
• Diet
• Stress
• Local trauma or injury
• Inflammation or infection

 

Pathogenesis

2. Growth factors: Epidermal growth factor, Endothelial growth factor, Fibroblast growth factor, Platelet-derived growth factor, Nerve growth factor,  Insulin-like growth factors: Hepatocyte growth factor,  Transforming growth factor,  Interleukins 1-7 [6]

3. Genes controlling growth: The genes which are controlling growth factors synthesis are named proto-oncogenes. If gene controlling growth factor is mutant or hyper activated it is named oncogen. Tumor suppressor gene or anti- oncogenes - their protein product inhibits mitosis

4. Mutagenic factors chemical - pro-carcinogens (substances that can convert to carcinogens) and carcinogens. : Aflatoxin (from fungus Aspergillus flavus) growing on stored grains, nuts and peanut butter  Cooking protein-rich food at high temperatures can lead to the formation of many potent carcinogens.  Industrial and tobacco smoke contain benzopyrene, tobacco-specific nitrosamines such as nitrosonornicotine Formaldehyde —embalming and making plastics.

5. Mutagenic factors physical (ionizing radiation, ultraviolet rays);  biological - viruses. The viral particles can carry a gene that encodes for an overactive oncogene called viral-oncogene and the infected cell is transformed into tumor cell. When tumor development occurs due to above mentioned cause carcinogenesis is named mutational [7].

General Pathogenesis of tumors

 Stage 1. INITIATION. Normal cell under the effect of etiological factors obtains capability to boundless growth and becomes tumor cell.

Stage 2. PROMOTION. Transformed cell under the effect of promotors (etiological factors that activate cell division) begins to multiply, giving the beginning to the clone (family) of daughter cells. The primary tumor tissue appears, which consists of similar cells [8].

Stage 3. Tumor progression. Regulatory systems of the organism affect the multiplying tumor cells. Tumor cells, in their turn, begin to adapt to the influence of regulatory systems. Thus, tumor cells getting from under the control of immune, endocrine and other regulatory systems of the organism, create new clones of cells. Tumor tissue obtains polymorphism (consists of different cellular clones that differ from each other), increases the speed of its growth, and obtains malignant character [9].

 

Morphology

1)    Macroscopically: a)Rate of growth Benign tumors are slowly growing tumors. Malignant tumors are rapidly growing tumors. b)Mode of growth Benign tumors grow as cohesive expansile masses that remain localized to their site of origin and do not have the capacity to infiltrate, invade or metastasize to distant sites. Malignant tumors grow as an invasive masses that can be expected to penetrate the wall of the uterus or the colon for example. C) Regarding the capsule Benign tumors ,because benign tumors grow and expand slowly,they usually develop a rim of compressed connective tissue,sometimes called a fibrous capsule,which separate them from the host tissue. This capsule keeps the benign neoplasm as a discete,rapidly palpapible,and easily movable mass that can be surgically removed. Malignant tumors,malignant tumors don’t have a capsule . Because they grow as an invasive masses, such invasiveness makes their surgical resection difficult or impossible. Exception to all of the above ,leiomyoma of the breast is a benign tumor that do not have a capsule. Renal cell carcinoma is a malignant tumor that have a capsule.

2)    d)Metastasis Metastasis marks a tumor as benign or malignant because benign neoplasm do not metastasize. 2)Microscopically :hemorrhage and necrosis are absent in benign neoplasm,but present in malignant tumors.

3)    3) Differentiation and anaplasia Differentiation refers to the extent to which neoplastic parencymal cells resemble the corresponding normal parenchymal cells,both morphologically and functionally, lack of differentiation is called anaplasia. In general benign tumors are well differentiated, malignant tumors are characterized by a wide range of parenchymal differentiation.,from Surprisingly well differentiated to completely undifferentiated [10].

Complications

The growth of benign tumors produces a "mass effect" that can compress tissues and may cause nerve damage, reduction of blood flow to an area of the body (ischaemia), tissue death (necrosis) and organ damage.

Symptoms of benign tumors

Not all tumors, cancerous or benign, have symptoms.

Depending on the tumor’s location, numerous symptoms could affect the function of important organs or the senses. For example, if you have a benign brain tumor, you may experience headaches, vision trouble, and fuzzy memory.

If the tumor is close to the skin or in an area of soft tissue such as the abdomen, the mass may be felt by touch.

Depending on the location, possible symptoms of a benign tumor include [11]:

• chills
• discomfort or pain
• fatigue
• fever
• loss of appetite
• night sweats
• weight loss

Benign tumors may be large enough to detect, particularly if they’re close to the skin. However, most aren’t large enough to cause discomfort or pain. They can be removed if they are. Lipomas, for example, may be large enough to detect, but are generally soft, movable, and painless. Some skin discoloration may be evident in the case of benign tumors that appear on the skin, such as nevi. Anything that looks abnormal should be evaluated by a doctor.

Diagnosis of benign tumors

Doctors use a variety of techniques to diagnose benign tumors. The key in diagnosis is determining if a tumor is benign or malignant. Only laboratory tests can determine this with certainty.

Your doctor may begin by performing a physical examination and collecting your medical history. They’ll also ask you about the symptoms you’re experiencing.

Many internal benign tumors are found and located by imaging tests, including:

• CT scans
• MRI scans
• mammograms
• ultrasounds
• X-rays

Benign tumors often have a visual border of a protective sac that helps doctors diagnose them as benign. Your doctor may also order blood tests to check for the presence of cancer markers.

In other cases, doctors will take a biopsy of the tumor to determine whether it’s benign or malignant. The biopsy will be more or less invasive depending on the tumor’s location. Skin tumors are easy to remove and only require a local anesthetic, while colon polyps would require a colonoscopy, for example, and a stomach tumor may require an endoscopy [4, 12].

Treatment of benign tumors

Not all benign tumors need treatment. If your tumor is small and isn’t causing any symptoms, your doctor may recommend taking a watch-and-wait approach. In these cases, treatment could be riskier than letting the tumor be. Some tumors will never need treatment.

If your doctor decides to pursue treatment, the specific treatment will depend on the location of the tumor. It may be removed for cosmetic reasons if, for example, it’s located on the face or neck. Other tumors that affect organs, nerves, or blood vessels are commonly removed with surgery to prevent further problems.

Tumor surgery is often done using endoscopic techniques, meaning the instruments are contained in tube-like devices. This technique requires smaller surgical incisions, if any at all, and less healing time [13].

Procedures like upper endoscopies and colonoscopies require almost no recovery time, though patients need someone to take them home and will likely sleep for the rest of the day. Skin tumor biopsies take a few weeks to fully heal and require basic recovery procedures like changing the bandage and keeping it covered. The more invasive the treatment, the more recovery time will be needed. Recovery from a benign brain tumor removal, for example, can take longer. Even once it’s removed, you may need speech therapy, occupational therapy, or physiotherapy to address problems the tumor left behind.

If surgery can’t safely access your tumor, your doctor may prescribe radiation therapy to help reduce its size or prevent it from growing larger.

While maintaining a healthy lifestyle, exercising, and eating a balanced diet can prevent health problems including some types of cancers, there aren’t natural or alternative remedies for benign tumors on their own.

 

 

 

 

 

 

 

 

Referneces

 

1.     What is cancer National Cancer Institute. 2007-09-17. Retrieved 2017-11-26. 

2.     Benign tumors. (2019).

3.     Lipoma. (2018). 

4.    Finkelstein MW. A guide to clinical differential diagnosis of oral mucosal lesions. dentalcare. com. 2010 Jul 22.

5.    Ambardekar N. Benign Tumors: Types, Causes, and Treatments [Internet]. WebMD. WebMD; 30, July 2019 . 

6.     Imanishi J, Kamiyama K, Iguchi I, Kita M, Sotozono C, Kinoshita S. Growth factors: importance in wound healing and maintenance of transparency of the cornea. Progress in retinal and eye research. 2000 Jan 1;19(1):113-29.

7.     Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P. Molecular biology of the cell, 5th edn. Garland Science. New York. 2008.

8.     Pitot, H.C., Goldsworthy, T., Moran, S. The natural history of carcinogenesis: Implications of experimental carcinogenesis in the genesis of human cancer. Journal of Supramolecular Structure and Cellular Biochemistry; Volume 17, Issue 2 , Pages 133 146. Published Online: 19 Feb 2004.

9.     Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., & Walter, P. Molecular Biology of the Cell; Fourth Edition. 23. Cancer. Garland Science; NY. 2002.

10. Nada A. Kamil, General Pathology, Tikrit University college of dentistry 2016-2017

11. the Healthline Editorial Team and Ana Gotter. Benign Tumors: Causes, Symptoms & Diagnosis [Internet]. Healthline. Healthline Media; 17, Sept, 2018 . 

12. Knoeller SM, Uhl M, Adler CP, Herget GW. Differential diagnosis of benign tumors and tumor-like lesions in the spine. Own cases and review of the literature. Neoplasma. 2004;51(2):117-26.

13. Meningioma [Internet]. Mayo Clinic. Mayo Foundation for Medical Education and Research;21, April, 2020.