Rosettes & Pseudorosettes - Neuropathology

This is one of the important topics in neuropathology  for diagnosis of brain tumors.To get the basic concept about different type of rosettes & in which tumors they occur & understand the topic better ,I have a nice article published in American Journal of NeuroRadiology.

You can download the pdf file from 4shared.

Lung cancer symptoms & treatment

Lung cancer is one of the most insidious & aggressive neoplasms in the whole realm of oncology.

 

symptoms:

• cough(75% cases)
• weight loss(40%)
• chest pain(40%)
• dyspnea(20%)

treatment:

Combinations of chemotherapy, radiation therapy,targeted therapy, or surgery may be of greater value than any single treatment alone.  

The treatment options for lung cancer are surgery, radiation therapy, chemotherapy, and targeted therapy either alone or in combination, depending on the stage of the tumor.

surgery:

Depending on the type and stage of the cancer, surgery may be used to remove the tumor and some of the lung tissue around it.

1. if  a lobe of lung removed-lobectomy.
2. if entire lung removed-pneumonectomy

 chemotherapy:

Chemotherapy refers to the use of drugs to kill cancer cells.

The drug combinations most frequently used for initial chemotherapy for non-small cell lung cancer are cisplatin or carboplatin combined with 1 of the following: 
Paclitaxel 
Docetaxel 
Gemcitabine 
Vinorelbine 
Irinotecan 
Etoposide 
Vinblastine 
Bevacizumab (targeted therapy used in combination) 

most commonly used combinations:

• Limited Stage- 
  Cisplatin and etoposide 
  Carboplatin and etoposide 
  
• Extensive Stage- 
  Cisplatin and etoposide 
  Carboplatin and etoposide 
  Cisplatin and irinotecan

1. 
   Chemotherapy drugs used if there has been a relapse of the small cell lung cancer include: 
   Ifosfamide, paclitaxel, docetaxel, or gemcitabine, if the relapse occurred within 2 to 3 months 

• 
  Topotecan, irinotecan, cyclophosphamide/doxorubicin/vincristine (CAV), gemcitabine, paclitaxel, docetaxel, oral etoposide, methotrexate, vinorelbine if the relapse occurred from 2 to 3 months to 6 months 
           
•  For relapses after 6 months, the original chemotherapy can be repeated.

Targeted therapy:
In the past few years, much lung cancer research has focused on drugs that are specifically targeted at cancer cells and interfere with their ability to grow.

1.erlotinib (Tarceva®)-for use in patients with NSCLC who are no longer responding to chemotherapy (this is usually determined after 1 or 2 different chemotherapy combinations)

      Common side effects of erlotinib include skin rash and diarrhea.

2.Bevacizumab (Avastin®)-most commonly used to treat colon cancer, but has also been studied as a treatment for NSCLC.

       side effects- Bevacizumab causes bleeding, which means it cannot be used in patients who are coughing up blood, whose cancer has spread to the brain, or who are on “blood thinners” (anticoagulation therapy). It also cannot be used in patients with squamous cell cancer, because it leads to bleeding from this type of lung cancer. Other rare but serious side effects include blood clots and high blood pressure  

3.Gefitinib (Iressa®) is a targeted therapy used to treat patients in good health, but with NSCLC that begins to grow after initially responding to treatment.

     side effects-diarrhea or skin reactions.

Radiation Therapy :Radiation therapy uses high-energy rays (such as x-rays) to kill or shrink cancer cells.

1.external radiation-most common used.

2.brachytherapy-from radioactive materials placed directly in the tumor (internal or implant radiation)

 a good site for more informaton about lung cancer. 

and a wonderful site with chest radiographs and mcqs

IMPORTANT POINTS ABOUT LUNG CANCER

Lung cancers are usually divided into two main groups that account for about 95% of all cases.
The division into groups is based on the type of cells that make up the cancer.


The two main types of lung cancer are characterized by the cell size of the tumor when viewed under the microscope. They are called small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). NSCLC includes several subtypes of tumors.

SCLCs are less common, but they grow more quickly and are more likely to metastasize than NSCLCs. Often, SCLCs have already spread to other parts of the body when the cancer is diagnosed.

About 5% of lung cancers are of rare cell types, including carcinoid tumor, lymphoma, and others.

The specific types of primary lung cancers are as follows:
Adenocarcinoma (an NSCLC) is the most common type of lung cancer, making up 30%-40% of all cases. A subtype of adenocarcinoma is called bronchoalveolar cell carcinoma, which creates a pneumonia-like appearance on chest x-rays.

Squamous cell carcinoma (an NSCLC) is the second most common type of lung cancer, making up about 30% of all lung cancers.

Large cell cancer (another NSCLC) makes up 10% of all cases.

SCLC makes up 20% of all cases.

Carcinoid tumors account for 1% of all cases.

DIFFERENCES B/W -small cell and non small cell types-

SCLC(small cell) exhibits

1.aggressive behavior,

2.with rapid growth,

3.early spread to distant sites,

4.exquisite sensitivity to chemotherapy and radiation, and

5.frequent association with distinct paraneoplastic syndromes.

6.Surgery usually plays no role in its management, except in rare situations (<5%>

risk factors:

1. Cigarette smoking is the most important cause of lung cancer
2. Passive smoking, or secondhand smoke
3. Air pollution
4. Asbestos exposure:. Another cancer known as mesothelioma (a type of cancer of the pleura or of the lining of the abdominal cavity called the peritoneum) is also strongly associated with exposure to asbestos.
5. Lung diseases, such as tuberculosis (TB) and chronic obstructive pulmonary disease (COPD), also create a risk for lung cancer
6. Radon exposure poses another risk.

Histologic Findings: The World Health Organization classification of lung cancer is widely accepted. NSCLC includes squamous cell carcinoma, adenocarcinoma, and large cell carcinoma. Sometimes, lung cancers can exhibit 2 or more histologic patterns.

Adenocarcinoma appears to be increasing in incidence, especially in women, compared with squamous cell carcinoma, which was previously the most common type of NSCLC.

Squamous cell carcinoma has a distinct dose-response relationship to tobacco smoking and usually develops in proximal airways, progressing through stages of squamous metaplasia to carcinoma in situ. Well-differentiated squamous cell carcinomas contain keratin pearls, while poorly differentiated squamous cell carcinomas may stain positive for keratin. Microscopic examination reveals cells with large, irregular nuclei and coarse nuclear chromatin with large nucleoli. Cells are arranged in sheets, and the presence of intercellular bridging is diagnostic.

Adenocarcinoma is the most common type of NSCLC. Histologically, adenocarcinomas form glands and produce mucin. Mucin production can be identified with mucicarmine or periodic acid-Schiff staining. The World Health Organization classification of lung cancer divides adenocarcinomas into (1) acinar, (2) papillary, (3) bronchoalveolar, and (4) mucus-secreting. Bronchoalveolar carcinoma is a distinct clinicopathologic entity that appears to arise from type II pneumocytes and may manifest as a solitary peripheral nodule, multifocal disease, or a pneumonic form, which can spread rapidly from one lobe to another. Stage for stage, adenocarcinomas are associated with worse prognoses than squamous cell carcinomas, with the exception of T1 N0 M0 tumors.

Large cell carcinoma is the least common of all NSCLCs. It is composed of large cells with prominent nucleoli, and no mucin production or intercellular bridging is identified. Many tumors previously diagnosed as large cell carcinomas are identified as poorly differentiated adenocarcinomas or squamous cell carcinomas after advanced immunohistochemical staining, electron microscopy, and monoclonal antibody studies. A variant of large cell carcinoma has been identified; it contains neuroendocrine features and is called large cell neuroendocrine carcinoma. Large cell neuroendocrine carcinomas are associated with a worse prognosis than large cell carcinomas.

SCLC typically are centrally located, arising in peribronchial locations. They are thought to arise from Kulchitsky cells.

The tumor is composed of sheets of small, round cells with dark nuclei, scant cytoplasm, fine granular nuclear chromatin, and indistinct nucleoli.

Crush artifact leading to nuclear molding is a common finding, but it is not considered diagnostic.

Very high rates of cell division are observed, and necrosis, sometimes extensive, may be seen. Because of the central location, the cells exfoliate in sputum and bronchial washings.

Neurosecretory granules can be identified on electron microscopy, and the neuroendocrine nature of the neoplasm is suggested by its frequent association with paraneoplastic syndromes caused by peptide hormones.

Immunohistochemical stains for chromogranin, neuron-specific enolase, and synaptophysin usually are positive.

thats for today more about its treatment tommorrow,bye