What are the other Names for this Condition? (Also known as/Synonyms)

• Mucinous Adenocarcinoma of Small Bowel
• Small Bowel Mucinous Adenocarcinoma
• Small Intestinal Mucinous Adenocarcinoma

What is Mucinous Adenocarcinoma of Small Intestine? (Definition/Background Information)

• Adenocarcinoma of small intestine is a rare tumor that may arise in any part of the small intestine that includes the duodenum, jejunum, and ileum. It is described as an epithelial cancer of the small intestine/bowel, meaning that it develops in the intestinal wall lining (the mucosal surface) and spreads to involve other layers and sites
• Mucinous Adenocarcinoma of Small Intestine is a very rare histological subtype of small bowel adenocarcinoma. The tumor is diagnosed under a microscope, on examination of the cancer cells by a pathologist. The subtype is denoted based on the predominant histologic pattern observed (presence of mucinous component)
• The cause of Mucinous Adenocarcinoma of Small Intestine is generally unknown. It is believed to be associated with genetic defects and certain food and lifestyle factors. Chronic Crohn’s disease is a major risk factor for cancer development; the cancer may develop a few decades after onset of Crohn’s disease
• The signs and symptoms of Small Intestinal Mucinous Adenocarcinoma may include abdominal pain, blood in stool, fatigue, and unexplained weight loss. Complications, such as tumor metastasis to distant sites, are known to occur
• The mainstay of treatment is surgical excision of the tumor, during the early stages. However, in many cases a combination of treatment measures that include surgery, chemotherapy, and radiation therapy may be necessitated
• The prognosis of Mucinous Adenocarcinoma of Small Intestine is generally poor, despite treatment. Some of the favorable prognostic factors include younger age of patient, early-stage of tumor, low-grade tumor, and site of tumor is either the jejunum or ileum

Who gets Mucinous Adenocarcinoma of Small Intestine? (Age and Sex Distribution)

• Mucinous Adenocarcinoma of Small Intestine is generally seen in middle-aged and older adults. When children and/or young adults are affected, it is mostly seen in the background of a predisposing (genetic) factor
• Both males and females are affected, although slightly more number of cases are observed in males
• All races and ethnic groups are at risk for the condition. However, more number of cases are seen in African-Americans than Caucasians

What are the Risk Factors for Mucinous Adenocarcinoma of Small Intestine? (Predisposing Factors)

The following factors are known to increase the risk for Mucinous Adenocarcinoma of Small Intestine:

• Longstanding inflammation of the small intestine such as due to inflammatory bowel disease (Crohn’s disease) and celiac disease
• Individuals undergoing pouch surgery or ileostomy (surgical removal of damaged portion of ileum) for ulcerative colitis or familial adenomatous polyposis are at risk, if intestinal metaplasia or dysplasia is noted in the ileal mucosal surfaces
• Smoking tobacco may increase the risk
• Alcohol consumption
• Presence of precursor small intestine lesion/adenoma
• Aging: The greater the age, the higher is the risk
• Presence of an associated genetic disorder such as
  • Familial adenomatous polyposis
  • Lynch syndrome
  • Polyposis syndrome
  • MUTYH-associated polyposis
  • Enteric duplication cysts
  • Peutz-Jeghers syndrome
  • Juvenile polyposis
• Individuals who undergo urinary bladder surgery, where a portion of the ileum is used to repair or restore the damaged urinary bladder or urine reservoir are at risk for developing adenocarcinoma in the ileal graft tissue
• Radiation therapy to the abdominal or pelvic region for cancer

Note: It is believed that the predisposing factors for both large intestine (colon) and small intestine are nearly the same, due to similar cause of development (etiology).

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one’s chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Mucinous Adenocarcinoma of Small Intestine? (Etiology)

The cause of development of Mucinous Adenocarcinoma of Small Intestine is generally unknown. It reportedly forms along similar lines as colorectal adenocarcinoma.

• Research scientists believe that the cause of the condition is mostly due to genetic mutations, influenced by factors that include food and lifestyle habits such as high-fat, high-calorie diet and sedentary lifestyle
• In individuals with chronic Crohn’s disease and celiac disease, intraepithelial neoplasia/dysplasia is noted before adenocarcinoma develops

What are the Sign and Symptoms of Mucinous Adenocarcinoma of Small Intestine?

In some individuals, Mucinous Adenocarcinoma of Small Intestine is detected while conducting diagnostic imaging tests for other medical conditions, since no symptoms may be observed during the early stages of cancer development.

Location of the tumor:

• Most tumors are seen in the duodenum: Adenocarcinomas seen in the duodenal region of small intestine is more than the combined number of cases observed at other small intestinal regions (such as in the jejunal and ileal regions)
• Near the ampulla of Vater (around the mouth where the bile duct and pancreatic duct discharge into the duodenum): It is believed that this is the more common site owing to increased exposure to fluids from the gallbladder and pancreas (in the presence of certain other conducive factors)
• At Meckel diverticulum, in rare cases

The signs and symptoms of Mucinous Adenocarcinoma of Small Intestine may include:

• The presence of an annular, nodular, or ulcerated mass
• GI tract bleeding: Bleeding through stool may take place over a long period, which can result in anemia
• Large tumors can frequently cause:
  • Abdominal (cramping) pain and discomfort
  • Swollen abdomen
  • Nausea and vomiting
• Presence of a palpable mass, when tumors are large
• Unexplained weight loss
• Narrowing of the intestine
• If the bile duct is obstructed by the tumor mass, it can result in jaundice
• Intraepithelial neoplasia/dysplasia, if any, may appear as polypoid or flat surface
• Annular tumors form around and constrict the gastrointestinal tract
• Annular tumors are usually seen in the jejunum and ileum, are larger in size, and infiltrate into the deeper layers of the surface
• Adenocarcinomas in duodenum are typically well-circumscribed, appear as an adenoma (protruding from the surface or polyp-shaped) and sometimes show ulceration
• Tumors at the ampulla of Vater may cause obstructive jaundice, even at small size. Such tumors are mostly well-defined (2-3 cm average size), may be appear as a polyp
• Many adenomas are discovered around the ampullary region
• Tumors that are confined to the surface are rarely associated with lymph node metastasis

How is Mucinous Adenocarcinoma of Small Intestine Diagnosed?

A diagnosis of Mucinous Adenocarcinoma of Small Intestine may be undertaken using the following tests and exams:

• Complete evaluation of family (medical) history, along with a thorough physical examination
• Stool sample analysis
• X-ray of the abdomen and pelvic region
• Barium enema X-ray
• Endoscopy for tumors in the duodenum (upper part of the small intestine). Capsule endoscopy is an effective tool for observing the small intestine along its entire length
• CT or MRI scan of the abdomen and pelvic region: CT scan with contrast or enteroclysis is a reliable procedure for diagnosing the tumor
• Abdominal ultrasound scan
• Upper GI endoscopy: An endoscopic procedure is performed using an instrument called an endoscope, which consists of a thin tube and a camera. Using this technique, the radiologist can have a thorough examination of the insides of the gastrointestinal tract
• Screening colonoscopy: A typical colonoscopy involves using a thin, flexible tube (called a colonoscope), with an attached video camera, to view the colon and rectum. It may help view the ileal and jejunal portions too
• Imaging studies, such as MRI scan, scintigraphy, and PET scan, may be performed to detect tumor invasion and metastasis
• Tissue biopsy of the tumor:
  • A tissue biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform special studies, which may include immunohistochemical stains, molecular testing, and very rarely, electron microscopic studies to assist in the diagnosis

Note:

• In many cases, tumors are diagnosed during advanced/later stages, especially when present in the jejunum or ileum
• When the ileum is involved, the adenocarcinoma may be misdiagnosed as a severe manifestation of Crohn’s disease

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Mucinous Adenocarcinoma of Small Intestine?

Some potential complications of Mucinous Adenocarcinoma of Small Intestine include:

• Emotional and psychological stress due to cancer diagnosis
• Iron-deficiency anemia, due to excess loss of blood
• Perforation of the small intestine by advanced tumors - this can lead to fluid in the peritoneal cavity (ascites), peritonitis, and blockage in the large intestine/colon
• Tumor infiltration to abdominal and pelvic organs, such as stomach, colon, rectum, and urinary bladder
• Metastasis to local and regional sites; spread of tumor to the lymph nodes (through the lymphatic system)
• In rare cases, the ovaries may be affected
• Recurrence of the tumor after treatment, especially due to partial surgical removal
• Anastomotic leak; leakage of GI tract contents following surgical procedures, which can result in severe infection and even sepsis
• Side effects due to cancer therapy

How is Mucinous Adenocarcinoma of Small Intestine Treated?

The treatment of cancer of the small intestine may depend upon a consideration of the following set of factors:

• The histological subtype of the cancer
• Stage of the cancer
• Size and location of the tumor
• Severity of the signs and symptoms
• Age of the individual
• Overall health status of the individual
• The treatment preferences of the individual

Mucinous Adenocarcinoma of Small Intestine may be treated in the following manner:

• Surgery is performed in most cases
• In case of lymph node metastasis, surgery is followed by chemotherapy and/or radiation therapy (adjuvant therapy)

The treatment measures include the following:

• Surgical removal of the entire tumor may be the preferred method of treatment (surgical resection)
• Cancers in the duodenum and near the pancreatic duct outlet may be treated through a surgical technique termed pancreaticoduodenectomy (or Whipple procedure)
• Chemotherapy: This approach uses a combination of drugs to kill the cancerous cells and can be used in patients, for all stages of the tumor
  • There can be severe side effects including fatigue, nausea, hair loss, anemia, high risk of infection, and drug-specific reactions
  • Chemotherapy can be administered as a pill, liquid, shot, or intravenously
• Radiation: Radiation therapy is the use of high-energy radiation waves to kill cancer cells, by destroying their DNA
  • This treatment modality may be used in combination with chemotherapy
  • The radiation may be administered by a machine placed outside the body, or by placing a radioactive material inside the body
  • The side effects of radiation therapy include nausea, vomiting, fatigue, pain, risk of cancer later in life, and risk of heart disease
  • Radiation can damage healthy cells in addition to cancer cells, causing further complications
• Supportive treatment: Steroids, blood transfusions, anti-nausea medications, and antibiotics, may be used as supportive therapy. In combination with other treatment measures, these can help combat the symptoms of immunodeficiency
• Palliative care for advanced tumors
• Undertaking treatment of underlying inflammatory bowel diseases/genetic disorders, as necessary

Regular observation and periodic checkups to monitor the condition is strongly recommended following treatment.

How can Mucinous Adenocarcinoma of Small Intestine be Prevented?

Presently, there are no specific methods or guidelines to prevent the formation of Mucinous Adenocarcinoma of Small Intestine. However, if it is associated with a genetic disorder, the following points may be considered:

• Genetic counseling and testing: If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
• Regular health check-ups might help those individuals with a history of the condition in the immediate family and help diagnose the tumor early

Factors that can help prevent or reduce incidence of the adenocarcinoma of small intestine (according to studies) include:

• It is important to undergo routine colonoscopy screenings as one gets older (over the age of 45-50 years), to ensure early detection of colon tumors or cancers
• Taking early and appropriate treatment for inflammatory bowel diseases, if any
• Consuming a diet that is rich in whole grains, vegetables, and fruits
• Taking foods rich in vitamin D and calcium
• Physical activities and regular exercising
• Avoidance of smoking; consuming alcohol in moderation
• In order to avoid a relapse, or be prepared for a recurrence, the entire diagnosis, treatment process, drugs administered, etc. should be well-documented and follow-up measures initiated

Regular medical screening at periodic intervals with blood tests, scans, and physical examinations are mandatory. Often several years of active vigilance are crucial and necessary.

What is the Prognosis of Mucinous Adenocarcinoma of Small Intestine? (Outcomes/Resolutions)

• The overall prognosis of Mucinous Adenocarcinoma of Small Intestine is poor. The 5-year overall survival rate for adenocarcinoma, in general, is around 30%
• However, typically the prognosis depends upon a set of several factors, which include: 
  • Stage of tumor: With lower-stage tumors, when the tumor is confined to site of origin, the prognosis is usually excellent with appropriate therapy. In higher-stage tumors, such as tumors with metastasis, the prognosis is poor
  • Overall health of the individual: Individuals with overall excellent health have better prognosis compared with those with poor health
  • Age of the individual: Older individuals generally have poorer prognosis than younger individuals
  • The size of the tumor: Individuals with small-sized tumors fare better than those with large-sized tumors
  • Location of the tumor: Tumors in the jejunal or ileal region have better prognosis than tumors in the duodenal region of the small bowel
  • Grade of the tumor: Poorly-differentiated tumors (high-grade) have poorer prognosis than well-differentiated tumors (low-grade)
  • Individuals with bulky disease have a poorer prognosis
  • Involvement of vital organs may complicate the condition
  • The surgical resectability of the tumor (meaning, if the tumor can be removed completely): Tumors that can be completely removed have better outcomes
  • Whether the tumor is occurring for the first time, or is a recurrent tumor. Recurring tumors have worse prognosis compared to tumors that do not recur
  • Response to treatment: Tumors that respond to treatment have better prognosis compared to tumors that do not respond to treatment
  • Progression of the condition makes the outcome worse
• The combination chemotherapy drugs used, may have some severe side effects (such as cardio-toxicity). This chiefly impacts the elderly adults, or those who are already affected by other medical conditions. Tolerance to the chemotherapy sessions is a positive influencing factor

An early diagnosis and prompt treatment of Mucinous Adenocarcinoma of Small Bowel generally yields better outcomes than a late diagnosis and delayed treatment.

Additional and Relevant Useful Information for Mucinous Adenocarcinoma of Small Intestine:

The following article link will help you understand other cancers and benign tumors:

http://www.dovemed.com/diseases-conditions/cancer/