10. Neoplasia 3 Flashcards
Familial adenomatous polyposis
(FAP) is an inherited condition in which numerous adenomatous polyps form mainly in the epithelium of the large intestine. While these polyps start out benign, malignant transformation into colon cancer occurs when left untreated.
Three variants are known to exist, FAP and attenuated FAP are caused by APC gene defects and autosomal recessive FAP (or MYH-associated polyposis) is caused by MUTYH gene defects. Of the three, FAP itself is the most severe and most common; although for all three, the resulting colonic polyps and cancers are confined to the colon wall and removal can greatly reduce the spread of cancer.
Retinoblastoma
rare, rapidly developing cancer that develops from the immature cells of a retina, the light-detecting tissue of the eye. It is the most common malignant cancer of the eye in children, and it is almost always found in young children.
Almost all children survive this cancer, although they may lose their vision in the affected eye(s) or need to have the eye removed.
Almost half of children with retinoblastoma have a hereditary genetic defect associated with retinoblastoma.
There are two forms of the disease, a heritable form and non-heritable form (all cancers are considered genetic in that mutations of the genome are required for their development, but this does not imply that they are heritable, or transmitted to offspring). Approximately 55% of children with retinoblastoma have the non-heritable form. If there is no history of the disease within the family, the disease is labeled “sporadic”, but this does not necessarily indicate that it is the non-heritable form. Bilateral retinoblastomas are commonly heritable, while unilateral retinoblastomas are commonly non-heritable.
In about two-thirds of cases, only one eye is affected (unilateral retinoblastoma); in the other third, tumours develop in both eyes (bilateral retinoblastoma).
Xeroderma pigmentosum
autosomal recessive genetic disorder of DNA repair in which the ability to repair damage caused by ultraviolet (UV) light is deficient. In extreme cases, all exposure to sunlight must be forbidden, no matter how small; as such
Multiple basal cell carcinomas (basaliomas) and other skin malignancies frequently occur at a young age in those with XP. In fact, metastatic malignant melanoma and squamous cell carcinoma are the two most common causes of death in XP victims.
Normally, damage to DNA in epidermal cells occurs during exposure to UV light. The absorption of the high energy light leads to the formation of pyrimidine dimers, namely cyclobutane-pyrimidine dimers and pyrimidine-6-4-pyrimidone photoproducts. In a healthy, normal human being, the damage is first excised by endonucleases. DNA polymerase then repairs the missing sequence, and ligase “seals” the transaction. This process is known as nucleotide excision repair.
Hereditary nonpolyposis colorectal cancer
Lynch syndrome
autosomal dominant genetic condition that has a high risk of colon cancer as well as other cancers including endometrial cancer (second most common), ovary, stomach, small intestine, hepatobiliary tract, upper urinary tract, brain, and skin.
The increased risk for these cancers is due to inherited mutations that impair DNA mismatch repair.
It is a type of cancer syndrome.
Bladder cancer
any of several types of cancer arising from the epithelial lining (i.e., the urothelium) of the urinary bladder.
Rarely the bladder is involved by non-epithelial cancers, such as lymphoma or sarcoma, but these are not ordinarily included in the colloquial term “bladder cancer.”
It is a disease in which abnormal cells multiply without control in the bladder
The most common type of bladder cancer recapitulates the normal histology of the urothelium and is known as transitional cell carcinoma or more properly urothelial cell carcinoma. Five-year survival rates in the United States are around 77%.
Bladder cancer is the 9th leading cause of cancer with 430,000 new cases and 165,000 deaths occurring in 2012.
Hepatocellular carcinoma
the most common type of liver cancer.
Most cases of HCC are secondary to either a viral hepatitis infection (hepatitis B or C) or cirrhosis (alcoholism being the most common cause of liver cirrhosis).
Treatment options of HCC and prognosis are dependent on many factors but especially on tumour size and staging. Tumour grade is also important. High-grade tumours will have a poor prognosis, while low-grade tumors may go unnoticed for many years, as is the case in many other organs.
HCC is a relatively uncommon cancer. In countries where hepatitis is not common, most cancers of the liver are not primary HCC but metastasis (cancers spread from elsewhere in the body such as the colon).
Malignant mesothelioma
Rare form of cancer that develops from cells of the mesothelium, the protective lining that covers many of the internal organs of the body.
most commonly caused by exposure to asbestos.
The most common anatomical site for mesothelioma is the pleura, but it can also arise in the peritoneum, the pericardium or the tunica vaginalis (a sac that surrounds the testis).
Signs and symptoms of mesothelioma include shortness of breath due to pleural effusion (fluid between the lung and the chest wall), chest wall pain and constitutional signs such as unexplained weight loss.
The diagnosis may be suspected based on chest X-ray and CT scan findings, but must be confirmed either by examining serous effusion cytology or with a biopsy (removing a sample of the suspicious tissue). A thoracoscopy (inserting a tube with a camera into the chest) can be used to acquire biopsy material, and allows the introduction of substances such as talc to obliterate the pleural space (a procedure called pleurodesis), preventing more fluid from accumulating and pressing on the lung. Despite treatment with chemotherapy, radiation therapy or sometimes surgery, mesothelioma carries a poor prognosis. Research about screening tests for the early detection of mesothelioma is ongoing.
Kaposi’s sarcoma
a tumor caused by infection with human herpesvirus 8
a systemic disease that can present with cutaneous lesions with or without internal involvement.
Four subtypes have been described: Classic KS, affecting middle aged men of Mediterranean descent; African endemic KS; KS in iatrogenically immunosuppressed patients; and AIDS-related KS.
The erythematous to violaceous cutaneous lesions seen in KS have several morphologies: macular, patch, plaque, nodular, and exophytic.
The cutaneous lesions can be solitary, localized or disseminated. KS can involve the oral cavity, lymph nodes, and viscera. Classic KS tends to be indolent, presenting with erythematous or violaceous patches on the lower extremities. African endemic KS and AIDS-related KS tend to be more aggressive. The AIDS-related KS lesions often rapidly progress to plaques and nodules affecting the upper trunk, face, and oral mucosa. The diagnosis can be made with a tissue biopsy and, if clinically indicated, internal imaging should be done.
Burkitt’s lymphoma
a cancer of the lymphatic system, particularly B lymphocytes found in the germinal center.
Currently, Burkitt lymphoma can be divided into three main clinical variants: the endemic, the sporadic, and the immunodeficiency-associated variants:
The endemic variant (also called “African variant”) most commonly occurs in children living in malaria endemic regions of the world (e.g., equatorial Africa, Brazil, and Papua New Guinea). Epstein-Barr virus (EBV) infection is found in nearly all patients. Chronic malaria is believed to reduce resistance to EBV, allowing it to take hold. The disease characteristically involves the jaw or other facial bone, distal ileum, cecum, ovaries, kidney, or breast.
The sporadic type of Burkitt lymphoma (also known as “non-African”) is the most common variant found in places where malaria is not holoendemic. The tumor cells have a similar appearance to the cancer cells of classical endemic Burkitt lymphoma. Sporadic lymphomas are rarely associated with the Epstein–Barr virus.[4] Non-Hodgkin lymphoma, which includes Burkitt’s, accounts for 30–50% of childhood lymphoma. The jaw is less commonly involved, compared to the endemic variant. The ileocecal region is the common site of involvement.
Immunodeficiency-associated Burkitt lymphoma is usually associated with HIV infection or occurs in the setting of post-transplant patients who are taking immunosuppressive drugs.
Burkitt lymphoma can be one of the diseases associated with the initial manifestation of AIDS.
