1. A. AROUS, A. MAALEJ, H. ABID, F. AKID, W. TURKI, S. HADDAR, KH. BEN MAHFOUDH, J. MNIF CHU HABIB BOURGUIBA – SFAX - TUNISIA ARAB CONGRESS OF RADIOLOGY 2012CHEST IMAGING : CH 1

2.  A lung nodule is defined as a “spot” on the lung that is between 0.5 and 3 cm in diameter.  If an abnormality is seen on an x-ray of the lungs that is larger than 3 cm, it is considered a “mass” instead of a nodule.  The availability and increasing number of chest CT scans in patients with pulmonary complaint cause frequent incidental findings of multiple pulmonary nodules.  The etiology of multiple pulmonary nodules can usually be determined with a thorough history and physical examination.  However, further testing is sometimes required for diagnosis, which may include additional imaging and/or a biopsy.

3. The objective of our study is to illustrate the contribution of the Computed Tomography (CT) in the etiologic diagnosis of the multiple pulmonary nodules.

4.  Retrospective study concerning 68 patients.  Age varies between 4 years and 77 years.  A thoracic CT was realized within the framework of a staging evaluation or control of a cancer (in 40 cases), or in front of a respiratory symptomatology with multiple pulmonary nodules in the chest radiography (in 28 cases).  The diagnosis was confirmed in all cases by the biology or by histological study.

5.  The diagnosis was confirmed in all cases by the biology or by histological study. Number of casesEtiologies 46Lung metastases 6lymphoma lung nodules 4tuberculosis 3pulmonary aspergillosis 3nodules rheumatoid 2pulmonary staphylococcia 1sarcoidosis 1candidiasis 1a Wegener's granulomatosis 1non-specific interstitial pneumonia

6.  These etiologies can be classified into three major categories:  Malignant tumor disease: This includes lung cancer, lymphomas, and cancer that has spread to the lungs from other parts of the body, among others.  Infectious disease: This includes bacterial infections such as tuberculosis, fungal infections such as histoplasmosis and coccidiomycosis, and parasitic infections.  Inflammatory disease: Conditions such as rheumatoid arthritis, sarcoidosis, and Wegener’s granulomatosis can cause lung nodules.

7.  With regard to malignancy, multiple pulmonary nodules occur primarily as a manifestation of metastatic disease, which can come either from an adenocarcinoma of the lung or from a distant primary.  Although it is not always recognized during life, 30 to 40% of cancer patients have pulmonary metastases at autopsy.  Cancer, particularly metastatic cancer, is a source of multiple pulmonary nodules, according to a 2007 article in the medical journal "Chest."  Multiple pulmonary nodules evoke metastatic cancer. and the rate of malignancy in nodules >20 mm is 81%.

8.  The nodules are variable in size and location, with a proclivity for the better perfused lung bases.  The lesions are usually round with sharply demarcated borders, although metastases with a tendency towards hemorrhage, such as choriocarcinoma, can also have indistinct, fuzzy borders.  Cavitation of metastatic lesions occurs in less than 5 percent of cases.  Non-Hodgkin's lymphoma can also cause multiple pulmonary nodules; these are more common in the lower lobes.  Intrapulmonary lymphoma nodules usually originate from the bronchial-associated lymphoid tissue (BALT). Cavitation occurs in less than 4 percent of cases.

9. In our study, concerning malignant etiologies, we have found:  The central localization of the nodules predominate in 78% of patients having a malignant etiology.  Lower lung distribution of nodules predominate in 86% of cases.  Solid nodules were found in all cases, while subsolid nodules were found in 4% of cases.  Speculated and irregular contours were found in 36 % of cases.  Lobulated contours were found in 7% of cases.  Angiocentric nodules were found in 13% of cases.  Excavated nodules were found in 13% of cases.  Calcification were found in 5% of cases.

10.  Patient follow-up for osteosarcoma  multiple pulmonary nodules scattered throughout both lungs: spiculated margin Cavitation Calcification Biopsy= Osteosarcoma lung metastases

11.  A women was diagnosed with an uterine carcinosarcomam since 2 years, consulting for chest pain.  multiple well defined lung parenchymal nodules predominate in the middle and lower lung zones  Excavated nodules in pulmonary apex  Pulmonary metastasis of an uterine carcinosarcoma

12.  An old man presents a dry cough with qn impaired general conditions  Multiple pulmonary nodules with lower lung distribution  Lobulated contours  Angiocentric nodule  Biopsy: Large B cell lymphoma

13.  Prolonged fever with cervical lymphadenopathy and dyspnea  A chest x-ray demonstrated a widened mediastinum  The chest CT scan demonstrated multiple pulmonary nodulesm one of them is excavated and present spiculated contours  Multiple mediastinal lymphadenopathy with pleural effusion  Biopsie: Hodgkin's lymphoma

14.  According to a 2005 journal article in "Radiology," various infections can cause pulmonary nodules. Several types of fungal infections appear as pulmonary nodules on x-ray. These include:  Multiple abscesses: bacteremic patients may develop multiple lung abscesses, which are more common in dependent areas of the lungs. Recurrent aspiration can yield multiple abscesses as well. Typically the lesions are between 0.5 and 3 cm in diameter, round, and well-defined. Formation of thick-walled cavities is common once the central necrotic debris has been expectorated through a bronchiolar communication.  Septic emboli: septic thrombophlebitis may generate septic emboli which produce multiple round or wedge-shaped nodules with a predilection for peripheral areas of the lower lobes. Cavitation is common, usually producing thin-walled lesions.

15.  Fungi: multiple pulmonary nodules can arise from a number of fungal infections, like histoplasmosis, coccidioidomycosis, or invasive Aspergillosis in immunocompromised hosts. In these cases, the lesions tend to range from 0.5 to 3 cm in diameter without a clear predilection for a specific area of the lungs. Patients with invasive Aspergillosis commonly display a surrounding halo of ground glass attenuation due to local hemorrhage (the halo sign), followed by cavitation and "crescent-sign" formation.  Tuberculomas of the lung: are round or oval lesions situated commonly in an upper lobe, the right more often than the left. Typically they are sharply circumscribed and has a diameter ranging from 0.5 to 4 cm or more. Lobulation may be present in 25% of cases, and satellite lesions may be identified in up to 80% of cases.

16. In our study, concerning infectious etiologies, we have found:  The central localization of the nodules predominate in 80% of cases.  Uper lung distribution of nodules predominate in 80% of cases.  halo sign were found in 2 cases of invasive aspergillosis.  Subsolid nodules were found in 20% of cases.  Excavated nodules were found in 30% of cases.  Calcification were found in one case of tuberculosis.

17.  Patient have received chemotherapy, present a persistent fever with neutropenia  Chest CT scan revealed multiple nodules and demonstrate in the right upper lobe an excavated nodule surrounded by ground-glass attenuation (halo sign)  Positive Aspergillus serology

18.  A young man. fever, weight loss, night sweats, and cough with expectoration  Subsolid nodules, it has indistinct margins  excavated nodule in the left upper lobe  Mycobacterium tuberculosis were found in a sputum sample

19.  Prolonged fever, and cough  Multiple pulmonary nodules, some of them are calcified  Pulmonary tuberculosis confirmed with biological tests

20.  Multiple pulmonary nodules may result from a number of noninfectious inflammatory conditions:  Wegener's Granulomatosis: is the most common, it is a disorder causing inflammation of the blood vessels that affects the kidneys, lungs, and upper airway. It causes inflammatory tissues, called granulomas, to grow in and around the blood vessels. It can produce multiple round, sharply or poorly demarcated lesions varying in size from 0.5 to 10 cm. Areas of consolidation may be associated with nodules, and cavitation occurs in slightly less than one-half of patients, generally producing a thick wall with an irregular inner lining

21.  Rheumatoid arthritis: it causes rheumatoid nodules in different areas of the body including the lungs. Pulmonary nodules can appear before, with, or after the onset of RA. They are more commonly multiple than single, vary from a few millimeters to several centimeters in diameter, and tend to involve both lungs these nodules usually occur at the periphery of the lung, just beneath the pleura, and occasionally can cause bronchopleural fistula, pneumothorax, and abscess formation or cavitation leading to hemoptysis.  Sarcoidosis: Lung involvement in sarcoidosis has a strong predilection for the upper lung. sarcoid granulomas in the lung are typically distributed along the lymphatic vessels. The pattern of distribution, upper lung predominance, and coexistence of mediastinal lymphadenopathy strongly indicate the presence of sarcoidosis. Nodules have well defined but irrigular contours.

22. In our study, concerning noninfectious inflammatory conditions, we have found:  The peripheral localization of the nodules were found in all cases.  Uper lung distribution of nodules predominate in sarcoidosis.  Solid nodules with well defined contours were found in all cases.  Excavated nodules were found in 40% of cases.  Calcification were found in 2 case of rheumatoid nodules.

23.  a woman followed for cutaneous sarcoidosis and has a dry cough with dyspnea.  multiple lung nodules some of which haves irregular contours with subpleural distribution  Bronchial distortion  Pulmonary sarcoidosis was confirmed by biopsy of a lymphadenopathy

24.  Pulmonary nodules in patients with Rhumatoide Arthritis  Perilyphatic distribution of nodules  Some of them are excavated  Thickened interlobular septum  Rheumatoid lung nodules

25.  Male patient presented with history of cough with since two months.  multiple pulmonary excavated nodules predominate in the right upper lobe withe a perepheral distribution  The c-ANCA is positive: Wegener's granulomatosis

26.  The multiple nodules must be analyzed according to semiological criteria concerning the aspect of margins and the distribution by taking into account the evolutionary context. The chest CT remains essential in the etiologic orientation and possibly in the histological confirmation.  A basilar predominance is typically noted in hematogenous metastases due to preferential blood flow to the lung bases. Nodules may also be either cavitary or surrounded by a "halo" of ground-glass attenuation, which is typical of hemorrhagic metastases such as those due to choriocarcinoma.

27.  If nodules are clustered in a predominantly subpleural/axial distribution, they are deemed to be perilymphatic in distribution. The main disease to be considered is sarcoidosis.  Less commonly, diffuse nodules may be identified in patients with septic emboli, invasive fungal infections, and pulmonary vasculitides. These entities frequently result in cavitary nodules, some with a distinct "halo" of ground-glass attenuation, and have even been described in patients with organizing pneumonia.

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