Mass On Lung Biography
(Source google.com)
In radiology, a solitary pulmonary nodule (SPN) or coin
lesion is a mass in the lungsmaller than 3 centimeters in diameter. It can be
an incidental finding found in up to 0.2% of chest X-rays and around 1% of
CT scans. The nodule most commonly represents a benign tumor such as a
granuloma orhamartoma, but in around 20% of cases it represents a malignant
cancer, especially inolder adults and
smokers. Conversely, 10 to 20% of patients with lung cancer are diagnosed in
this way. Thus, the possibility of cancer needs to be excluded through further
radiological studies and interventions, possibly including surgical resection.
Theprognosis depends on the underlying condition. A solitary pulmonary nodulus needs to be separated from
larger lung tumors, smaller infiltrates or masses with other accompanying
characteristics. An often used formal radiological definition is the following:
a single lesion in the lung completely surrounded by lung parenchyma
(functional tissue) with a diameter less than 3 cm and without
associatedpneumonia, atelectasis (lung collapse) or lymphadenopathies (swollen
lymph nodes).
Not every round spot on a radiological image is a coin
lesion: it should not be confused with the projection of a structure of the
chest wall or skin, such as a nipple, a healing rib fracture or
electrocardiographic monitoring. The most important cause to exclude is a form of lung
cancer, including rare forms such as primary pulmonary lymphoma, carcinoid
tumor and a solitary metastasis to the lung (common unrecognised primary tumor
sites are melanomas, sarcomas or testicular cancer). Benign tumors in the lung
include hamartomas and chondromas. The most common benign coin lesion is a
granuloma (inflammatory nodule), for example due to tuberculosis or a fungal infection.
Other infectious causes include a pulmonary abscess, pneumonia (including
Pneumocystis carinii pneumonia) or rarely nocardial infection or worm infection
(such as dirofilariasis or dog heartworm infestation). Lung nodules can also
occur in immune disorders, such asrheumatoid arthritis or Wegener's
granulomatosis, or organizing pneumonia. An SPN can be found to be an arteriovenous malformation, a
hematoma or an infarction zone. It may also be caused by bronchial atresia,
sequestration, an inhaled foreign body or pleural plaque. Several features help to distinguish benign conditions from
possible lung cancer. The first parameter is the size of the lesion: the
smaller, the less risk for alignant cancer. Benign causes tend to have a well
defined border, whereas lobulated lesions or those with an irregular margin
extending into the neighbouring tissue tend to be malignant. If there is a
central cavity, then a thin wall points to a benign cause whereas a thick wall
is associated with malignancy (especially 4mm or less versus 16mm or more). In
lung cancer, cavitation can represent central tumor necrosis (tissue death) or
secondary abscessformation. If the walls of an airway are visible (air
bronchogram), bronchioloalveolar carcinomais a possibility. An SPN often
contains calcifications. Certain patterns of calcification are reassuring, such
as the popcorn-like appearance of hamartoma. An SPN with a density below 15
Hounsfield units on computed tomography tends to be benign, whereas malignant
tumors often measure more than 20 Hounsfield units. Fatty tissue inside
hamartomas will have a strongly negative value on the Hounsfield scale. The
growth velocity of a lesion is also informative: very fast or very slow growing
tumors are rarely malignant, in contrary to inflammatory or congenital
conditions. It is therefore important to retrieve previous imaging studies to
see if a lesion was presented and how fast its volume is increasing. This is
more difficult for nodules smaller than 1 centimeter. Moreover, the predictive
value of stable lesion over a period of 2 years has been found to be rather low
and unreliable.
The work-up in patients with a solitary pulmonary nodule is
based on an initial risk assessment. If the risk of malignancy is thought to be
low, follow-up imaging (usually serial CT scans) can be planned at a later
time. The frequency of further scans can be determined by the patient's risk
for cancer and the size of the nodule. If the initial impression is that there
is a high likelihood of cancer, then a surgical intervention is appropriate
(provided that the patient is fit for surgery). If there is an intermediate risk of malignancy, further
imaging with positron emission tomography (PET scan) is appropriate (if
available). Around 95% of patients with a malignant nodule will have an
abnormal PET scan, while around 78% of patients with a benign nodule will look
normal on PET (this is the test sensitivity and specificity). Thus, an abnormal
PET scan will reliably pick up cancer, but several other types of nodules
(inflammatory or infectious, for example) will also show up on a PET scan. If
the nodule has a diameter below 1 centimeter, PET scans are often avoided
because there is an increased risk of falsely normal results. Cancerous lesions
usually have a high metabolism on PET, as demonstrated by their high uptake of
FDG (a radioactive sugar). If the lesion is found on further imaging to be
suspicious, it should be surgically excised (via thoracotomy or video-assisted
thoracic surgery) to confirm the diagnosis by microscopical examination. In selected cases, nodules can also be sampled through the
airways using bronchoscopy or through the chest wall using needle aspiration
(which can be done under CT guidance). Needle aspiration can only retrieve
groups of cells for cytology and not a tissue cylinder or biopsy, precluding
evaluation of the tissue architecture. Theoretically, this makes the diagnosis
of benign conditions more difficult, although rates higher than 90% have been
reported. Complications of the latter technique include hemorrhage into the
lung and air leak in the pleural space between the lung and the chest wall
(pneumothorax). However, not all these cases of pneumothorax need treatment
with a chest tube. Other imaging techniques include PET-CT (simultaneous PET
scan and CT scan with superposition of the images), magnetic resonance imaging
(MRI) or single photon emission computed tomography (SPECT).
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
Mass On Lung Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee of a Weed Smoker
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