FAQs: Lung Cancer (includes carcinoid, mesothelioma): LUNGCA
UNDERSTANDING YOUR PATHOLOGY REPORT: A FAQ SHEET
When your lung was biopsied, the samples taken were studied under the microscope by a specialized doctor with many years of training called a pathologist. The pathology report tells your treating doctor the diagnosis in each of the samples to help manage your care. This FAQ sheet is designed to help you understand the medical language used in the pathology report.
1. What is "carcinoma"?
Lung carcinoma is synonymous with lung cancer which is a malignant tumor, although it can be curable when caught early.
2. What is "infiltrating" or "invasive"?
These words mean the same. The normal lung is made of air passages (bronchi) that end in a group of blind-ending sacs (acini) where your blood gets oxygenated. Carcinomas start out inside bronchi or acini and when the break out of these structures and are no longer confined to these structures, they are considered invasive or infiltrating carcinoma. This means that tumor cells can now migrate to other parts of your body (metastasize).
3. What does it mean if my carcinoma is called "squamous carcinoma" or "squamous cell carcinoma"?
Depending on whether carcinoma begins in the bronchi (ducts) or in the acini (air-filled sacs), they may look different under the microscope. Squamous cell carcinoma arises mainly from the bronchi and is one the most frequent types of lung cancer in Western countries.
4. What does it mean if my carcinoma is called "adenocarcinoma"?
Depending on whether carcinoma begins in the bronchi (ducts) or in the acini (air-filled sacs), they may look different under the microscope. Adenocarcinoma arises mainly from the acini and is one of the most frequent types of lung cancer in Western countries and is rapidly becoming the most common form of lung cancer.
5. What does it mean if the following terms are used to describe the adenocarcinoma: "papillary", "bronchioloalveolar", "nonmucinous", "mucinous", "micropapillary", or "solid"?
These are different types of lung adenocarcinoma which can be pure or sometimes in the same cancer there can be a mixture of patterns. These terms describe the way the tumor cells grow in the lung and are seen under the microscope. Some growth patterns are prognostically better (ie. bronchioloalveolar), while others are worse (ie. micropapillary). However, a definite diagnosis of these types of cancer cannot always be established on needle biopsy or a bronchoscopic biopsy, since some tumors may have mixed features. Only if most of the tumor shows these features, which can only be done once the entire tumor is removed on wedge resection or lobectomy, can these types of cancer be definitively diagnosed.
6. What does it mean if my carcinoma is called "small cell carcinoma", "oat cell carcinoma", or "small cell undifferentiated carcinoma"?
Small cell carcinoma is a very aggressive type of lung cancer that is initially very responsive to treatment with chemotherapy and radiation. However, typically after a year or two the cancer begin to grow again (recur). Small cell carcinoma has often spread outside of the lungs at presentation and therefore is not amenable to surgical excision. It usually is treated with different chemotherapy than other (non-small cell) carcinomas.
7. What does it mean if my carcinoma is called "large cell carcinoma" or "large cell undifferentiated carcinoma"?
In some cases the cancer does not resemble squamous cell carcinoma, adenocarcinoma, small cell carcinoma, or any of the other rarer variants of lung cancer. These cancers are "undifferentiated large cell carcinoma" or "non-small cell carcinoma". The prognosis of these tumors is better than small cell carcinoma and in general they are treated in the same way as adenocarcinoma of the lung.
8. What does it mean if my cancer is called "malignant mesothelioma"?
These are cancers that arise on the outer surface (pleura) of the lung. They are often associated with prior exposure to asbestos. Typically these tumors are associated with a poor prognosis. Mesotheliomas can look different under the microscope with some having "epithelial" features, others "spindled" or "sarcomatoid" features or "mixed epithelial and spindle cell" features. The prognosis of malignant mesothelioma does not vary significantly depending on its pattern, although therapy may vary.
9. What does it mean if my report says that there is "metastatic carcinoma to the lung"?
Cancers from other organs (such as the gastrointestinal tract) often spread to the lung. Even though they are in the lung, they are not lung cancers. For example, if an adenocarcinoma of the colon (ie colon cancer) spreads (metastasizes) to the lung it is not the same as when we refer to a primary adenocarcinoma of the lung (cancer originating in the lung). When cancers from other sites have spread to the lung, the prognosis is significantly worsened.
10. What does it mean if my carcinoma is "well-differentiated", "moderately-differentiated", or "poorly differentiated"?
These terms are used to indicate how aggressive your carcinoma is likely to be. It is made by a pathologist looking at the cancer under the microscope. Well-differentiated carcinomas tend to be more slowly growing with a better prognosis. Poorly-differentiated carcinomas are the most aggressive tumors with a worse prognosis with moderately-differentiated carcinomas having an intermediate prognosis.
11. What does it mean if my report says "typical carcinoid" or "atypical carcinoid" tumor?
Typical carcinoid tumors are considered low grade (relatively indolent) types of lung cancer, not associated with smoking. The prognosis is typically excellent. Atypical carcinoid tumors is when a carcinoid tumor has certain features seen with the microscope that indicates the potential for more aggressive behavior. Some of the features that may be mentioned in your report of an atypical carcinoid include: mitotic figures or mitoses (an indication of how fast the tumor is growing) and necrosis (when there are areas of dead tumor).
12. What is "vascular", "angiolymphatic" or "lymphovascular invasion"? What if my report mentions D2-40 (podoplanin) or CD34?
Tumors can break into small vessels seen under the microscope which is called "vascular" or "lymphovascular invasion". The presence of tumor in vessels is associated with an increased risk that the tumor has spread outside the lung, although this does not always occur. Usually the first site lung cancers spread to are the lymph nodes in the lung itself followed by lymph nodes in your chest near the heart (mediastinal lymph nodes). Tumor cells in lymph nodes is a bad prognostic finding as is the finding of tumor cells in other organs. D2-40 and CD34 are special tests that the pathologist may do to help identify vascular invasion. These tests are not necessary in every case. If your report does not mention vascular or lymphovascular invasion, it means it is not present. Even with vascular invasion your cancer could still be very curable depending on other factors. How this finding will affect your specific treatment is best discussed with your treating doctor.
13. What is the significance of the reported size of the tumor?
The pathologist typically will measure the greatest dimension (diameter) of the tumor as seen under the microscope or by gross (naked eye) examination (if visible). Cancers on needle biopsy are not given a measurement, as the more accurate measurement will be done on the subsequent excision (wedge or lobectomy). In general, the larger the tumor, the worse the prognosis.
14. What is the significance of the stage of the tumor?
The stage of the tumor is a measurement of its extent both in the lung and whether there is any spread beyond the lung. A stage is typically not given for a needle biopsy specimen as the pathologist does not have the entire tumor to evaluate. For lobectomy specimens, a stage is usually reported that factors in the size of the tumor, which is indicated by "pT" followed by numbers and letters to indicate its size. The larger the number, typically the larger the tumor. "pN" followed by numbers and letters indicate if and the extent of spread to any lymph nodes (see below) that may have been removed with the specimen. "pMx" means that the pathologist cannot determine whether there is spread to distant sites (ie. lung, liver, bone) because this must be determined by radiographic studies. How the stage of your tumor will affect your therapy is best discussed with your treating physician.
15. What does it mean if my report mentions special studies such as p63, cytokeratin 5/6, and TTF-1?
p63, cytokeratin 5/6, and TTF-1 are special tests that the pathologist sometimes uses to help distinguish whether the cancer is adenocarcinoma or squamous cell carcinoma.
16. What does it mean if my report mentions special studies such as ck7 (cytokeratin 7), ck20, CDX2, gross cystic duct fluid protein (GCDFP), mamaglobin, estrogen receptor (ER), progesterone receptor (PR), along with TTF-1 or PE-10?
These tests are sometimes used to help determine if a cancer in the lung is primary (ie started in the lung) or represent a metastasis (spread) to the lung from another organ. Not all cases need these tests. Whether your report does or does not mention these tests has no bearing on the accuracy of your diagnosis.
17. What does it mean if my report mentions special studies such as CD56, chromogranin, or synaptophysin?
These tests are sometimes used to help determine if a cancer in the lung is a small cell carcinoma. These tests can also be used to help make the diagnosis of carcinoid or atypical carcinoid tumor.
18. What does it mean if my report mentions special studies such as mesothelin, D2-40 (podoplanin), calretinin, CEA, cytokeratin (CK) 5/6, HBME-1, Ber-EP4, TTF-1, CD15 (LeuM1), WT-1?
These tests are sometimes used to help determine if a tumor in the lung is mesothelioma or an adenocarcinoma of the lung.
19. What does it mean if in addition to cancer my report also says "atypical adenomatous hyperplasia" or "squamous dysplasia" or "squamous cell carcinoma in-situ (DCIS)"?
All of these terms are pre-cancerous conditions that the pathologist sees under the microscope. These typically are of no importance when seen on needle biopsy if there is invasive cancer elsewhere on the sampling. If they are seen on an excision where there is cancer, they may be important if present at or near a margin (see FAQ relating to margins below).
20. What if my report mentions EGFR or K-ras?
These molecular tests help to determine which tumors could respond to specific types of chemotherapy. How the results of your tests will affect your therapy is best discussed with your treating physician.
21. What if my report mentions "margins" or "ink"?
When an excisional biopsy (wedge or lobectomy) is performed, the pathologist coats the outer aspect of the specimen with ink, sometimes different colored ink. If carcinoma extends to the ink, it indicates that they have not been completely removed, depending on what additional specimens the surgeon may have removed. The management of "invasive carcinoma", "in-situ carcinoma" (pre-cancer), or "atypical adenomatous hyperplasia"(pre-cancer at a margin is best discussed with your treating physician.
22. What does it mean if my report also says any of the following terms: "scarring", "emphysema", "emphysematous changes", or "inflammation"?
All of these terms are non-cancerous things that the pathologist sees under the microscope and usually are of no great importance when seen on a biopsy where there is cancer.
23. What if my report mentions any of the following: "granulomas", "methenamine silver (GMS)", "acid fast bacilli (AFB)", or "Periodic Acid Schiff (PAS)".
Granulomas are structures seen under the microscope that are often, although not necessarily, an indication of certain types of infection. These types of infections can be detected with special stains (ie. GMS, stains for AFB, and PAS) that the pathologist can apply to the slides.