Pulmonary Nodule by A.Griguolo

Generality

A pulmonary nodule is an abnormal formation, generally isolated, round or oval, which is located on one of the two lungs.

A pulmonary nodule may have a benign or malignant nature; in the first case (benign nature), it presents in the list of possible causes such conditions as tuberculosis, histoplasmosis, aspergillosis, sarcoidosis, rheumatoid arthritis and some particular types of benign tumors; in the second case (malignant nature), instead, it is the result of cancerous processes (it is, that is, a malignant tumor).

Pulmonary nodules tend to be asymptomatic, except when they are large.

To identify a pulmonary nodule, it is essential to use imaging diagnostics, in particular the RX-thorax or thoracic CT scan.

The therapeutic approach to a pulmonary nodule varies according to the nature of the formation: if no specific treatment is required for benign pulmonary nodules, surgical removal is indispensable for malignant pulmonary nodules.

What is a Pulmonary Nodule?

A pulmonary nodule, or lump in the lung, is an anomalous formation, generally isolated, of a round or oval aspect, which has its origin on the parenchyma of the lungs and can have a benign or malignant nature.

Pulmonary nodules are usually small sized structures; in fact, in fact, their diameter is kept below 3 centimeters.

Physicians have a tendency to define the presence of a pulmonary nodule with the expression " isolated pulmonary nodule " or " solitary pulmonary nodule ".

Benign Pulmonary Nodule and Malignant Pulmonary Nodule: the main differences

To distinguish benign pulmonary nodules from malignant pulmonary nodules are:

The dimensions . Benign pulmonary nodules rarely exceed 3 centimeters in diameter; the malignant pulmonary nodules, on the other hand, almost always have a diameter greater than 3 centimeters;
The speed of growth . Benign pulmonary nodules grow very slowly; malignant pulmonary nodules, on the other hand, are capable of doubling their size in less than 30 days;
The frequency of appearance . Benign pulmonary nodules are decidedly (and fortunately) more common than malignant pulmonary nodules.
The consequences on lung function . Benign pulmonary nodules very rarely alter lung function, while malignant pulmonary nodules affect it drastically.

Thus, summing up, compared to malignant pulmonary nodules, benign pulmonary nodules are smaller, grow very slowly, characterize most pulmonary nodule diagnoses and compromise lung function only in rare cases.

Clarification on the naming of large pulmonary nodules

Pulmonary nodules larger than 3 centimeters in diameter are called lung masses .

Causes

The appearance of a pulmonary nodule recognizes different causes, depending on whether the formation is benign or malignant.

Causes of Benign Pulmonary Nodule

Possible causes of benign pulmonary nodules include:

Bacterial infections sustained by Mycobacterium tuberculosis ( tuberculosis ) or intracellular Mycobacterium avium and fungal infections sustained by Aspergillus ( aspergillosis ), Histoplasma capsulatum ( histoplasmosis ), Coccidioides ( coccidiomycosis ), Cryptococcus neoformans ( cryptococcosis ).
The pulmonary nodules associated with the aforementioned infections are examples of granuloma ; a granuloma is a cellular cluster, which appears following an inflammatory process aimed at isolating substances considered foreign to the organism.
Non-infectious conditions, such as sarcoidosis, granulomatosis with polyangiitis and rheumatoid arthritis ;
Benign tumors such as fibroma, hamartoma, neurofibroma or blastoma .

Causes of Malignant Pulmonary Nodule

Malignant pulmonary nodules are always the result of malignant tumor processes; in fact, they can represent the onset of cancerous forms, such as pulmonary adenocarcinoma, pulmonary lymphoma, pulmonary carcinoid or pulmonary sarcoma, or the result of metastases reaching the lung from a malignant tumor arising elsewhere.

What is a tumor? When is it benign and when, on the other hand, is it malignant?

A tumor is a mass of very active cells, able to divide and grow uncontrollably.

A tumor is called benign, when the growth of cell mass is not infiltrative (that is, it does not invade the surrounding tissues) or even metastasizing.
Instead, a tumor is called malignant (or cancer or malignant neoplasm), when the abnormal mass of cells has the ability to grow very quickly and spread to the surrounding tissues and the rest of the body.

WHO IS MORE AT RISK OF DEVELOPING A MALIGNO PULMONARY NODULE?

Stats in the hand, people in whom it is more common to find a malignant pulmonary nodule are smokers (NB: cigarette smoking is the main risk factor for lung cancer), elderly people and those who, for various reasons, are been exposed for long periods to asbestos or other carcinogens .

Epidemiology

In most cases, the appearance of a pulmonary nodule has a benign origin;
The probability that a pulmonary nodule is malignant increases with the size of the formation; in fact, according to the most reliable estimates, if only 10% of pulmonary nodules with a diameter of less than 2 centimeters are malignant, as much as 40-50% of the pulmonary nodules with a diameter greater than 3 centimeters is instead malignant;
According to some studies, malignant pulmonary nodules are, in almost 50% of cases, examples of pulmonary adenocarcinoma;

The risk of tracing a malignant pulmonary nodule in a person grows parallel to age; in fact, this risk is 3%, for subjects under the age of 39; reaches 15%, for individuals aged between 40 and 49; exceeds 50%, for those over 60;
The finding of a malignant pulmonary nodule is more frequent in smokers and in the elderly.

Symptoms and Complications

In general, the presence of a pulmonary nodule is not directly associated with any symptom, except when the size of the abnormal formation is considerable.

In other words, pulmonary nodules tend to remain asymptomatic, as long as they are small in size.

The lack of a symptomatology associated with pulmonary nodules is a negative aspect of these formations, as it hinders their diagnosis (this is particularly dangerous, when a pulmonary nodule is malignant).

Important!

If it is true that pulmonary nodules tend to be asymptomatic, it is equally true that many of their causes are conditions characterized by precise symptomatic pictures.

For example, tuberculosis is responsible for fever, decreased appetite, night sweats, chills, weight loss and a tendency to tire easily.

The symptoms of the conditions typically related to the appearance of an isolated pulmonary nodule are of enormous help in suspecting the presence of the latter and researching them with specific diagnostic tests.

When is a Symptomatic Pulmonary Nodule most likely to be observed?

The probability of encountering a symptomatic pulmonary nodule is greater, when the formation has a malignant nature. This is related to the general tendency of malignant pulmonary nodules to be larger than the benign pulmonary nodules.

Possible manifestations of a symptomatic pulmonary nodule

The symptoms that can arise from a pulmonary nodule are few and consist substantially in: cough, cough with consistent production of sputum, hemoptysis (ie cough with blood emission) and hemoptysis (ie presence of blood in the sputum ).

Complications

The presence of a pulmonary nodule can give rise to complications, when the nature of the training is malignant.

Specifically, in such circumstances, the possible complications are a profound compromise of the respiratory faculties and the general state of health, and the spread of metastases in other parts of the body (eg: brain or bones).

The complications associated with malignant pulmonary nodules are the result of an evolution of such formations, an evolution that has increased its size and caused some of its constituent cells (metastasis) to be dispersed.

Diagnosis

For the diagnosis of a pulmonary nodule, chest radiological examinations are essential, such as chest X -ray (or chest X-ray ) or thoracic CT (or chest CT scan ).

These instrumental tests, in fact, are able to photograph the internal thoracic organs (ie, bones, heart, lungs, large vessels etc.) and reproduce them, through one or more detailed images, on a special film (the so-called radiological plate).

RX-thorax and thoracic CT compared

RX-thorax is less effective than thoracic CT in identifying a pulmonary nodule; however, it exposes the patient to a decidedly smaller quantity of harmful ionizing radiation.
The RX-thorax is able to identify pulmonary nodules at least 1 centimeter large; the thoracic CT, on the other hand, can show pulmonary nodules of even 1-2 millimeters;
Of a pulmonary nodule, the RX-thorax provides a poorly detailed image, from which only features such as shape, position and size are perceived; the TAC, on the other hand, ensures a rich reproduction of information, so much so that the doctor is able, at times, to establish the internal density of the training.

Did you know that ...

Only one RX-chest on 500 brings to light a pulmonary nodule, in people who are carriers of it.

What is the next step in finding a Pulmonary Nodule?

It is a practice that, immediately after the finding of a pulmonary nodule, all the diagnostic investigations that are useful to establish the cause of the anomalous formation and its nature begin.

The list of the diagnostic investigations in question certainly includes the anamnesis, the physical examination, the blood tests and a second radiological examination after some time from the first, and, in particular situations, it could also include PET and a biopsy pulmonary .

ANAMNESIS AND OBJECTIVE OBJECTIVE

In a context of pulmonary nodule, medical history and physical examination serve to clarify two aspects:

If the patient suffers or has suffered in the past from symptoms that can somehow be linked to one of the possible causes of pulmonary nodule (eg: a recent history of fever, night sweats, fatigue etc. could be the consequence of a sustained infection from Mycobacterium tuberculosis ).
If the patient falls into some category at risk of malignant pulmonary nodules (eg: he is a smoker, he is an elderly person etc.).

WHAT DOES A SECOND RADIOLOGICAL EXAMINATION NEED?

A second chest X-ray examination performed some time after the first one (ex: one month) is used to see if the pulmonary nodule has enlarged or changed its appearance.

Did you know that ...

Malignant pulmonary nodules are not only larger than benign pulmonary nodules, but also have a more irregular shape.

The analysis of the shape of a pulmonary nodule is one of the investigations useful for understanding the nature of training.

PULMONARY BIOPSY

Lung biopsy consists of the collection and analysis in the laboratory of a sample of suspected lung tissue.

The lung biopsy performed on a pulmonary nodule allows to establish with precision the nature of the formation; in this sense, it is the most accredited test .

The use of lung biopsy to study the nature of pulmonary nodules occurs only when previous examinations have been limited and doubts still remain.

Therapy

The treatment of a pulmonary nodule varies according to whether the formation is benign or malignant.

For benign pulmonary nodules, no specific therapy is provided, but only the management of the triggering condition (clearly, when this is still in progress).

A benign pulmonary nodule is generally not subjected to surgical removal or to other medical treatments that concern it directly.

The only medical indication in these circumstances is to treat the triggering condition.

For malignant pulmonary nodules, on the other hand, it is essential to provide for the removal of the abnormal formation, by means of surgery.

Surgical Techniques of Excision of a Malignant Pulmonary Nodule

Currently, various techniques exist for the removal of a malignant pulmonary nodule; among these techniques, they deserve a quotation:

Thoracotomy . It is an "open" (therefore invasive) surgical operation, which involves the incision of the chest and the removal of the portion of the lung on which the pulmonary nodule resides.

Video-assisted thoracoscopy . It is a minimally invasive procedure, which bases the removal of the pulmonary nodule on the introduction into the thoracic cavity of an instrument called a thoracoscope.
Thoracoscopy is based on the same principles of arthroscopy (small incisions, use of a tubular instrument equipped with a camera, etc.).

Prognosis

The prognosis in case of pulmonary nodule depends on the nature of the training; for benign pulmonary nodules, it tends to be benign; for in malignant pulmonary nodules, instead, there is a non-negligible risk that can be ominous.