The cervicothoracic sign is used to determine if a mediastinal mass is located in the anterior or posterior mediastinum based on whether its superior border is obscured at or below the clavicles. However, this sign can be misleading, as demonstrated by a case of a superior mediastinal mass that appeared to have a positive cervicothoracic sign on x-ray due to the projection of the anterior part of the mass being clearer than the posterior part. Therefore, the cervicothoracic sign should not be solely relied upon to determine the location of a mediastinal mass.

1. CERVICOTHORACIC SIGN
IS ITALWAYS DEPENDABLE?
DR. C RAVINDRAN MD, DTCD, FRCP
PROFESSOR & SENIOR CONSULTANT
DEPT. OF PULMONARY MEDICINE

4. CERVICOTHORACIC SIGN
• When the cephalic border of a mass is obscured at or below the
level of the clavicles, it is deemed to be a “cervicothoracic lesion”
involving the anterior mediastinum (Positive cervicothoracic
sign).
• Mediastinal masses posterior to the trachea are well outlined
above the level of the clavicles (Negative cervicothoracic sign)
due to the interface with lung in the posterior aspects of the lung
apices.
• Superior mediastinal mass usually have a sharp well delineated
lateral border due to the aerated lung giving a good contrast.
• If it is in the anterior mediastinum the superior border ends at the
clavicle as the anterior mediastinum do not extend beyond
clavicle.
• At the same time posterior mediastinal mass extends above the
clavicle and the lateral border can be traced above the clavicle

5. FALLACY
• As per the above rule the lesion in figure A is an anterior
mediastinal mass as the cervicothoracic sign is positive.
• Look at the CT Thorax.
• It shows a superior mediastinal mass touching both anterior
and posterior chest wall
• Its base is towards the posterior aspect.

7. EXPLANATION
• This can be explained by the projection of X-Ray chest
PA view where anterior lesion is close to x-ray film and
will be more clear and sharp when compared to posterior
part which is distant from the film.
• So in this case even though the mass extends to posterior
mediastinum, anterior part is denser and clearly visible to
the eyes when compared to more distant posterior part.
• So the onlooker has a visual illusion that the lesion stops
at clavicle like an anterior mediastinal mass.
• This is a fallacy of cervicothoracic sign.