42 |
4 Abnormal Lung Patterns |
Fig. 4.12 PA again, with arrows highlighting masses. Also note blunting of the costophrenic angle on the right (Eff)
•Benign neoplasm
•Congenital
Based on location of masses in this case, extra-parenchymal considerations should include the anterior mediastinal mass differential (the 6 “Ts”). This particular case was lymphoma.
Granulomatous Disease
A granulomatous reaction in the chest usually produces nodules or small masses in the lungs. The earliest manifestations may be diffuse interstitial or mixed infiltration in the form of nodules consisting mainly of epithelioid macrophages and other inflammatory and immune cells.
Granulomatous conditions are classified here as either infectious or noninfectious for the purposes of findings and arriving at a reasonable differential.
Table 4.1 identifies some of the many and varied granulomatous mass (nodule) patterns that can be seen on CXR.
Mass |
43 |
Table 4.1 Patterns and characteristics supporting granulomatous disease |
|
Lung mass |
Solitary pulmonary nodule |
Radiological characteristics |
|
Homogenous soft tissue density |
Soft tissue (or calcific) density less than 3 cm in |
|
diameter |
Density greater than 3 cm in diameter |
Distinct margins |
(less than 3 cm is a nodule) |
|
Sharp margins |
Oval or round |
Masses do not respect fissures, however, |
Consider metastasis |
may displace them |
|
Granulomatous etiologies |
|
Granulomatous infections (Tuberculosis |
Granulomas (often calcified) |
[TB], Histoplasmosis Blastomycosis) |
|
Wegener’s granuloma |
Other infectious etiology |
|
Benign nodules |
Lymphadenopathy |
Cavity |
Radiological characteristics |
|
Widening of mediastinum |
Number: single or multiple (consider metastasis) |
Polycyclic margin |
Size: mm to cm |
Clear space between heart and the nodal |
Location: apices of lobes for TB, classical |
density with hilar nodes |
segments for aspiration |
Extra-pleural sign with mediastinal nodes |
Thickness of wall: thick, thin |
Obliteration of silhouette based on location |
Fluid level: consider abscess, fungous ball |
Widening of carina with subcarinal nodes |
Lumen: regular or irregular |
|
Associated findings |
Granulomatous etiologies |
|
Granulomatous diseases |
Wegener’s granuloma |
TB |
Granulomatous infections, TB, Histoplasmosis |
Sarcoidosis |
See the “CAVITY” mnemonic |
Histoplasmosis |
|
Silicosis |
|
|
|
Note: Consider neoplasia/metastasis with any mass
Note: you can use CAVITY as a mnemonic to help you remember the differential for cavitary lesions in the chest:
CAVITY:
C – Cancer, congenital, or acquired bullae
A – Abscess
V – Vasculitis
I – Infection (fungal, granulomatous)
T – Tuberculosis (TB)
Y – cYst (posttraumatic)