Clubbing in the fingers of a 33-year old female with pulmonary hypertension.
Clubbing in the fingers of a 33-year old female with pulmonary hypertension.

Nail clubbing is found in 29% of lung cancer patients!

‘Fingernail clubbing’ is one of most well-know indicators for recognizing cancer in the hand. A.k.a. ‘Hippocratic nail’ this nail characteristic been known since the early days of the Greek philosopher Hippocrates, who recognized nail clubbing as a classic sign of disease.

Today ‘nail clubbing’ is associated various lung diseases, especially lung cancer with non–small cell lung carcinoma. Nail clubbing is also linked with heart problems and gastrointestinal problems – but these are less common than lung problems.

Statistics on nail clubbing & lung cancer:

“Nail clubbing has been reported in 29% of patients with lung cancer and is observed more commonly in patients with non–small cell lung carcinoma (35%) than in patients with small cell lung carcinoma (4%).”

How to recognize ‘clubbing fingernails’?

Clubbing is usually a painless but complex fingernail disorder which often goes unnoticed of it’s presence in the hands of patients!

In individuals without clubbing, if two opposing fingers are placed together, a diamond-shaped window will appear. In clubbing, this window is obliterated and the distal angle formed by the two nails becomes wider. This is known as Schamroth sign window test.

Schamroth's windows test is used in the diagnosis of nail clubbing.

NOTICE: Cases of ‘brachydactyly’ should NOT be associated with the medical problems related to ‘nail clubbing’; the ‘clubbed thumb’ is likely the most well-known variant of ‘brachydactyly’ – which is e.g. seen in the hands of the american actress Megan Fox

Actress Megan Fox has a ‘clubbed thumb’ – which should not be confused with ‘nail clubbing’.
American actress Megan Fox has a 'clubbed thumb' - which should NOT be associated with 'nail clubbing'.

SUGGESTION FOR FURTHER READING:

Nail clubbing: developments, treatment & prevention!
Hands on lung cancer: the clubbing fingernail!
Fingernail disorders & medical hand analysis!
Overview of more common nail disorders!
Megan Fox has a ‘clubbed thumb’ – not to be confused with ‘fingernail clubbing’!!