Primitive Neuroectodermal Tumors of the Soft Tissue or Bone

Primitive neuroectodermal tumors or PNET are very rare group of tumors that are highly malignant. In clinical manifestation these tumors exhibit great diversity. They manifest in the bone and soft tissue. Pathologist find them very difficult to distinguish because they have similarities to other small, round tumors.

                                                    PNET tumors under a microscan

PNET tumors are classified into three groups.

I. CNS primitive neuroectodermal tumors (PNETs) - Tumors derived from the central nervous system

II. Neuroblastoma - Tumors derived from the autonomic nervous system

III.Peripheral primitive neuroectodermal tumors (pPNETs) - Tumors derived from tissues outside the central and autonomic nervous system

This cancer is usually seen in children and adolescents and is very fast growing and can quickly metastasize to other organs.

Peripheral primitive neuroectodermal tumors (pPNETs) are also classified as part of the Ewing family of tumors (EFTs); peripheral primitive neuroectodermal tumors (pPNETs) and Ewing family of tumors (EFTs) are often referred to interchangeably in the literature. Generally, Ewing family of tumors (EFTs) and peripheral primitive neuroectodermal tumors (pPNETs) represent different manifestations of the same tumor and have similar genetic alterations. Ewing sarcoma, however, is more common in bone, while peripheral primitive neuroectodermal tumors (pPNETs) are more common in soft tissues. Immunohistochemical and cytogenetic studies suggest that these tumors all have a common origin.

Tissue biopsy with cytogenetic and immunohistochemical studies is paramount in diagnosing peripheral primitive neuroectodermal tumors (pPNETs). Radiologic studies such as CT scans and MRI are essential in determining the limits of tumor involvement and ruling out metastatic disease. On CT scans, peripheral primitive neuroectodermal tumors (pPNETs) appear as heterogeneous masses, often invading surrounding tissues, including bone. MRI reveals a mass isointense to muscle on T1-weighted images, while hyperintense on T2-weighted image 

^{Due to the fact that PNET is metastatic then full body scans need to be performed to see the extent of the tumor growth.} 

^{Treatment Plan}

Chemotherapy and radiation are necessary adjuncts in the treatment of primitive neuroectodermal tumors (PNETs). Chemotherapy regimens have significantly improved outcomes in patients with peripheral primitive neuroectodermal tumors (pPNETs). The treatment paradigms differ based on whether the disease is localized or metastatic. As would be expected, the treatments for peripheral primitive neuroectodermal tumors (pPNETs) and Ewing family of tumors (EFTs) are similar in terms of chemotherapeutic regimens.
Current recommendations advocate complete surgical resection whenever possible, adjuvant versus neoadjuvant chemotherapy, and radiotherapy. Multimodality treatment is advocated to prevent metastatic disease, recurrent disease, and to treat residual tumor after resection. Carvajal and Meyers, in a comprehensive review of the chemotherapeutic regimens in the treatment of PNETs and Ewing family of
 tumors (EFTs), recommend a regimen that includes vincristine, doxorubicin, and cyclophosphamide with ifosfamide and etoposide.
For more specific information:
http://emedicine.medscape.com/article/855644-overview#aw2aab6b8
 

Facts about Ovarian Metastastis From the Colon

According to the Mayo Clinic, "Symptoms of ovarian cancer are nonspecific and mimic those of many other more common conditions, including digestive and bladder disorders." Colon cancer may also spread to the lymph nodes, bones, lungs and liver. There are particular signs and symptoms that the cancer has spread to the ovaries.

Abdominal Discomfort

• Patients with colon cancer that has spread to the ovaries may have already been experiencing pain, fullness or bloating in the abdomen from the colon cancer and may not realize the cancer has spread. Patients may also experience persistent indigestion, gas or nausea as well as changes in bowel habits, such as constipation. One may lose their appetite or quickly feel full after a meal.

Pelvic Discomfort

• Women may experience pain during intercourse, lower back pain and general pelvic discomfort. According to the Mayo Clinic, patients may also experience changes in bladder habits, including a frequent need to urinate as well as changes in menstruation (more bleeding, much less bleeding or erratic bleeding).

The following is an abstract from a Colorectal Medical Journal

Abstract

Objective  To improve management of ovarian metastasis through assessment of clinicopathological features and treatment outcomes associated with ovarian metastasis from colorectal cancer.

Method  We recruited 103 subjects who were diagnosed with ovarian metastasis and subjected to surgery between June 1989 and December 2005. Clinical and pathological variables were evaluated. Survival and its associated factors were analysed with a median follow-up of 31 months after ovarian surgery (range 1–129 months).

Results  The mean age at diagnosis was 46 years (range 14–72 years), synchronous ovarian metastasis occurred in 74 patients and metachronous in 29 patients. The primary tumour was more commonly associated with the colon rather than the rectum (84/1608, 5.2%vs 19/1534, 1.2%, P < 0.001). Combined metastases occurred in 69 patients (67%). Complete resection was achieved in 34 (33%) patients without other metastases. The estimated 5-year disease free survival and overall survival rate were 40.1% and 26.6%, respectively. From univariate analysis, lymphovascular invasion (35.6%vs 12.8%, P = 0.034), combined metastasis (50.9%vs 15.6%, P = 0.0035) and bilaterale ovarian metastasis (36.4%vs 10.6%, P = 0.015) were identified as significant poor prognosis factors, and from multivariate analysis combined metastasis and bilaterale ovarian metastasis were significant (P = 0.034 and P = 0.015, respectively).

Conclusion  This study suggests a role for regular follow-up computed tomography scans within 6 months postoperatively and tumour marker assays for the early detection of ovarian metastasis in premenopausal women after primary surgery, especially in colonic patients with poor prognostic factors.

Diagnosis

A pelvic examination and imaging including CT scan^[39] and trans-vaginal ultrasound are essential. Physical examination may reveal increased abdominal girth and/or ascites (fluid within the abdominal cavity). Pelvic examination may reveal an ovarian or abdominal mass. The pelvic examination can include a Rectovaginal component for better palpation of the ovaries. For very young patients, magnetic resonance imaging may be preferred to rectal and vaginal examination.
To definitively diagnose ovarian cancer, a surgical procedure to take a look into the abdomen is required. This can be an open procedure (laparotomy, incision through the abdominal wall) or keyhole surgery (laparoscopy). During this procedure, suspicious areas will be removed and sent for microscopic analysis. Fluid from the abdominal cavity can also be analysed for cancerous cells. If there is cancer, this procedure can also determine its spread (which is a form of tumor staging).

Staging

Ovarian cancer staging is by the FIGO staging system and uses information obtained after surgery, which can include a total abdominal hysterectomy, removal of (usually) both ovaries and fallopian tubes, (usually) the omentum, and pelvic (peritoneal) washings for cytopathology. The AJCC stage is the same as the FIGO stage. The AJCC staging system describes the extent of the primary Tumor (T), the absence or presence of metastasis to nearby lymph Nodes (N), and the absence or presence of distant Metastasis (M).^[43]

• Stage I — limited to one or both ovaries
  • IA — involves one ovary; capsule intact; no tumor on ovarian surface; no malignant cells in ascites or peritoneal washings
  • IB — involves both ovaries; capsule intact; no tumor on ovarian surface; negative washings
  • IC — tumor limited to ovaries with any of the following: capsule ruptured, tumor on ovarian surface, positive washings
• Stage II — pelvic extension or implants
  • IIA — extension or implants onto uterus or fallopian tube; negative washings
  • IIB — extension or implants onto other pelvic structures; negative washings
  • IIC — pelvic extension or implants with positive peritoneal washings

 Advanced Ovarian Cancer

Ovarian adenocarcinoma deposit in the mesentry of the small bowel

• Stage III — peritoneal implants outside of the pelvis; or limited to the pelvis with extension to the small bowel or omentum
  • IIIA — microscopic peritoneal metastases beyond pelvis
  • IIIB — macroscopic peritoneal metastases beyond pelvis less than 2 cm in size
  • IIIC — peritoneal metastases beyond pelvis > 2 cm or lymph node metastases
• Stage IV — distant metastases to the liver or outside the peritoneal cavity

                                   Testimonial of Patient with Colon Cancer that Metastasized to Ovary

http://ovariancancer.jhmi.edu/prognosis.cfm

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2650975/
 

The Facts About Bone Cancer

Did you know that bone cancer rarely is the only location that cancer is seen in the human body? Usually it is spread or metastasized by remote cancers in other organs of the body.

                                              Bone tumor by X-Ray

                                            Bone Cancer under the microscope from biopsy

Notice the abnormal growth of cells in the picture above which indicates cancer.

The Most Common Types of Bone Cancers :

• Osteosarcoma, which arises from osteoid tissue in the bone. This tumor occurs most often in the knee and upper arm (1).
• Chondrosarcoma, which begins in cartilaginous tissue. Cartilage pads the ends of bones and lines the joints. Chondrosarcoma occurs most often in the pelvis (located between the hip bones), upper leg, and shoulder. Sometimes a chondrosarcoma contains cancerous bone cells. In that case, doctors classify the tumor as an osteosarcoma.
• The Ewing Sarcoma Family of Tumors (ESFTs), which usually occur in bone but may also arise in soft tissue (muscle, fat, fibrous tissue, blood vessels, or other supporting tissue). Scientists think that ESFTs arise from elements of primitive nerve tissue in the bone or soft tissue (2). ESFTs occur most commonly along the backbone and pelvis and in the legs and arms (3).

Other types of cancer that arise in soft tissue are called soft tissue sarcomas. They are not bone cancer and are not described in this resource.

What are bone cancer symptoms and signs?

The most common symptom of bone tumors is pain. In most cases, the symptoms become gradually more severe with time, including bone pain. Initially, the pain may only be present either at night or with activity. Depending on the growth of the tumor, those affected may have symptoms for weeks, months, or years before seeking medical advice. In some cases, a mass or lump may be felt either on the bone or in the tissues surrounding the bone. This is most common with MFH or fibrosarcoma but can occur with other bone tumors. The bones can become weakened by the tumor and lead to a fracture after little or no trauma or just from standing on the affected bone. This can occur with both benign and malignant tumors. Even benign tumors can spread locally and weaken the surrounding bone. If the tumor compresses the surrounding nerve it can cause pain, numbness, or tingling in the extremities. If the surrounding blood vessels are compressed, it can affect the blood flow to the extremities. Fever, chills, night sweats, and weight loss can occur but are less common. These symptoms are more common after spread of the tumor to other tissues in the body.

What are the possible causes of bone cancer?

Although bone cancer does not have a clearly defined cause, researchers have identified several factors that increase the likelihood of developing these tumors. Osteosarcoma occurs more frequently in people who have had high-dose external radiation therapy or treatment with certain anticancer drugs; children seem to be particularly susceptible. A small number of bone cancers are due to heredity. For example, children who have had hereditary retinoblastoma (an uncommon cancer of the eye) are at a higher risk of developing osteosarcoma, particularly if they are treated with radiation. Additionally, people who have hereditary defects of bones and people with metal implants, which doctors sometimes use to repair fractures, are more likely to develop osteosarcoma (4). Ewing sarcoma is not strongly associated with any heredity cancer syndromes, congenital childhood diseases, or previous radiation exposure (2).

What are the treatment options for bone cancer?

Treatment options depend on the type, size, location, and stage of the cancer, as well as the person’s age and general health. Treatment options for bone cancer include surgery, chemotherapy, radiation therapy, and cryosurgery.

• Surgery is the usual treatment for bone cancer. The surgeon removes the entire tumor with negative margins (no cancer cells are found at the edge or border of the tissue removed during surgery). The surgeon may also use special surgical techniques to minimize the amount of healthy tissue removed with the tumor.
  Dramatic improvements in surgical techniques and preoperative tumor treatment have made it possible for most patients with bone cancer in an arm or leg to avoid radical surgical procedures (removal of the entire limb). However, most patients who undergo limb-sparing surgery need reconstructive surgery to maximize limb function (1).
• Chemotherapy is the use of anticancer drugs to kill cancer cells. Patients who have bone cancer usually receive a combination of anticancer drugs. However, chemotherapy is not currently used to treat chondrosarcoma (1).
• Radiation therapy, also called radiotherapy, involves the use of high-energy x-rays to kill cancer cells. This treatment may be used in combination with surgery. It is often used to treat chondrosarcoma, which cannot be treated with chemotherapy, as well as ESFTs (1). It may also be used for patients who refuse surgery.
• Cryosurgery is the use of liquid nitrogen to freeze and kill cancer cells. This technique can sometimes be used instead of conventional surgery to destroy the tumor (1).
  
  
  
  This video educates us on how bone cancer is diagnosed.  To learn more about bone cancer then go to the following websites :
  
  http://www.cancer.gov/cancertopics/factsheet/Sites-Types/bone
  
  http://www.medicinenet.com/bone_cancer/page3.htm