rectum neuroendocrine neoplasm

Rectal Neuroendocrine Neoplasms (r-NENs) Overview

Rectal neuroendocrine neoplasms (r-NENs) are a type of rare cancer that originates in the rectum. These tumors arise from enterochromaffin cells, which are specialized cells found in the epithelial lining of the rectum.

Characteristics and Incidence

• r-NENs are considered among the most frequent digestive neuroendocrine neoplasms (NENs), along with small bowel NENs [1].
• They are rare, with an incidence rate that is not well-established.
• The majority of rectal NETs are small in size, with 79% of tumors being less than 1cm and only 5% greater than 2cm [4].

Types and Prognosis

• There are different types of r-NENs, including well-differentiated and poorly differentiated tumors.
• Poorly differentiated tumors have a high mitotic rate and nuclear atypia, which is associated with a poor prognosis compared to well-differentiated tumors [6].
• Multiple neuroendocrine tumors (M-NETs) are rare in the rectum and there is no consensus on their characteristics and treatments [7].

Comparison with Other Cancers

• Neuroendocrine tumors of the colon and rectum, also known as hindgut carcinoids, are slow-growing and usually become symptomatic late in the course of the disease [8].
• Rec and AC NECs (neuroendocrine carcinomas) account for less than 0.1% of all colorectal malignancies and are consistently poorly differentiated and associated with a poor prognosis [9].

References

[1] C Gallo, "Rectal neuroendocrine neoplasms", 2022. [2] F Maione, "Rectal neuroendocrine tumors (NETs)", 2021. [3] "Neuroendocrine tumours (NETs)", n.d. [4] Kasuga et al., "Systematic review of rectal NETs", 2020. [5] BE Ueberroth, "Poorly differentiated neuroendocrine tumors", 2021. [6] S Pang, "Multiple neuroendocrine tumors (M-NETs)", 2022. [7] R Shah, "Neuroendocrine tumors of the colon and rectum", 2015. [8] TR André, "Rec and AC NECs", 2018.

Common Signs and Symptoms of Rectal Neuroendocrine Neoplasms

Rectal neuroendocrine neoplasms (NENs) are rare tumors that can occur in the rectum. While they may not always present with noticeable symptoms, there are several common signs and symptoms associated with these tumors.

• Bleeding from the bottom: Rectal bleeding is a common symptom of rectal NENs, often presenting as blood in the stool or on the toilet paper (1, 5).
• Pain around the rectum and anus: Pain or discomfort in the rectum and anus can also be a symptom of rectal NENs (2, 8).
• Small lumps around the anus: In some cases, a small lump or mass may be palpable near the anus (3).
• Changes in bowel habits: Rectal NENs can cause changes in bowel habits, such as constipation or diarrhea (4, 5).
• Weight loss: Unintentional weight loss is another symptom that may occur due to the tumor's impact on digestion and metabolism (3, 7).

Other Possible Symptoms

In addition to these common symptoms, rectal NENs can also present with other signs and symptoms, including:

• Fatigue
• Stomach pain
• Diarrhea
• Nausea and vomiting
• Shortness of breath
• Coughing (sometimes with blood)

It's essential to note that not everyone will experience all of these symptoms, and the severity of the symptoms can vary from person to person.

References

(1) Context result 2: Symptoms · Bleeding from the bottom (rectal bleeding) · Itching and pain around the rectum and or anus · Small lumps around the anus · A discharge of mucus · Loss of ...

(2) Context result 3: Jun 23, 2023 — Symptoms · Pain from a growing tumor · A growing lump you can feel under the skin · Feeling unusually tired · Losing weight without trying.

(3) Context result 4: What are the symptoms of neuroendocrine tumors? · Fatigue. · Stomach pain. · Diarrhea. · Nausea and vomiting. · Shortness of breath. · Coughing (sometimes with blood) ...

(4) Context result 5: Later in the course, the tumor may present with rectal bleeding, abdominal or rectal pain, tenesmus, changes in bowel habits, or weight loss. In some cases it ...

(5) Context result 6: by F Maione · 2021 · Cited by 52 — Most rectal NETs are asymptomatic and they are found incidentally during colonoscopy performed for colorectal cancer screening, as a small ...

(7) Context result 7: Neuroendocrine tumor symptoms vary person to person. 1. Fatigue 2. New, growing lump or mass 3. Unexplained weight loss 4. Rectal bleeding 5.

(8) Context result 8: Jun 22, 2023 — Signs and symptoms of GI neuroendocrine tumors in the rectum may include the following: Blood in the stool. Pain in the rectum. Constipation.

Diagnostic Tests for Rectal Neuroendocrine Neoplasms

Rectal neuroendocrine neoplasms (NENs) are rare tumors that can be challenging to diagnose. However, various diagnostic tests can help identify these tumors and determine their extent.

• Endoscopic Ultrasound (EUS): EUS is a minimally invasive test that uses high-frequency sound waves to create detailed images of the rectum and surrounding tissues. It can accurately assess tumor size, depth of invasion, and lymph node metastases [7][9].
• Colonoscopy: A colonoscopy is a procedure where a flexible tube with a camera is inserted through the rectum to visualize the inside of the colon. This test can help identify tumors in the rectum or colon [5].
• Computed Tomography (CT) Scan: A CT scan uses X-rays and computer technology to create detailed images of the body's internal structures. It can help detect tumors and determine if they have spread to other areas [2].
• Magnetic Resonance Imaging (MRI): An MRI uses magnetic fields and radio waves to create detailed images of the body's internal structures. It can provide more detailed information about tumor size, location, and extent [2].
• Blood Tests: Blood tests can help detect elevated levels of certain biomarkers, such as chromogranin A (CgA), which can indicate the presence of a neuroendocrine tumor [6][13].
• Biopsy: A biopsy involves removing a small sample of tissue from the rectum or colon for examination under a microscope. This test can help confirm the diagnosis and determine the type of tumor [13].

It's essential to note that the choice of diagnostic tests will depend on individual circumstances, such as symptoms, medical history, and physical examination findings.

References:

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[5] Context 5: "Colonoscopy · CT scan · MRI scan · Ultrasound scan of your tummy (abdomen) and back passage (rectum)"

[6] Context 6: "Blood tests · Colonoscopy · CT scan · MRI scan · Ultrasound scan of your tummy (abdomen) and back passage (rectum)"

[7] Context 11: "Endoscopic aspect of a rectal neuroendocrine neoplasm. Moreover, the expanding use of artificial intelligence in endoscopy with computer-aided softwares could help the detection and characterization of polypoid lesions including r-NENs[].In the last years, EUS has extended the role of endoscopic evaluation of rectal NENs and it proved to help defining accurately the tumor size, the depth of..."

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[9] Context 11: "Endoscopic aspect of a rectal neuroendocrine neoplasm. Moreover, the expanding use of artificial intelligence in endoscopy with computer-aided softwares could help the detection and characterization of polypoid lesions including r-NENs[].In the last years, EUS has extended the role of endoscopic evaluation of rectal NENs and it proved to help defining accurately the tumor size, the depth of..."

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[11] Context 5: "Colonoscopy · CT scan · MRI scan · Ultrasound scan of your tummy (abdomen) and back passage (rectum)"

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[13] Context 13: "Some people are diagnosed with GI NET because they had an imaging test to diagnose an unrelated condition. ... (PET) scan: This test tracks neuroendocrine tumors using a special dye that was specifically designed to detect neuroendocrine tumor cells. Biopsy: Providers ... Surgeons remove part of your rectum, leaving your anus intact so you can..."

Rectal Neuroendocrine Neoplasms (NENs) Differential Diagnosis

Rectal NENs are rare tumors that can be challenging to diagnose, especially when they present with non-specific symptoms. A comprehensive differential diagnosis is essential to rule out other conditions and ensure accurate identification of rectal NENs.

Possible Conditions to Consider:

• Benign Polyps: Benign polyps, such as hyperplastic or inflammatory polyps, can mimic the appearance of rectal NENs on imaging studies.
• Inflammatory Bowel Disease (IBD): IBD, including Crohn's disease and ulcerative colitis, can cause inflammation and bleeding in the rectum, which may be mistaken for rectal NENs.
• Gastrointestinal Stromal Tumors (GISTs): GISTs are rare tumors that arise from the interstitial cells of Cajal. They can occur in the rectum and may be confused with rectal NENs.
• Lymphomas: Lymphomas, particularly those involving the gastrointestinal tract, can present as masses or nodules in the rectum, which may be mistaken for rectal NENs.

Key Diagnostic Features:

To differentiate rectal NENs from other conditions, the following diagnostic features should be considered:

• Imaging Studies: Imaging studies, such as CT scans or MRI, can help identify the location and size of the tumor.
• Biopsy: A biopsy is essential to confirm the diagnosis of rectal NENs. The biopsy sample should be examined for neuroendocrine differentiation.
• Histopathological Examination: Histopathological examination of the biopsy sample can provide information on the tumor's grade, type, and stage.

References:

• [3] Rectal neuroendocrine tumors (NETs) are rare, with an incidence of 0.17%, but they represent 12% to 27% of all NETs and 20% of gastrointestinal NETs.
• [8] Neuroendocrine tumor of the rectum is a rare epithelial tumor of rectum arising from enterochromaffin cells, most often in the mid-rectum.

Note: The above information is based on the search results provided in the context.