Finger Clubbing due to Lung Cancer

Author: V. Dimov, M.D.
Reviewer: S. Randhawa, M.D.

A 56-year-old African American male (AAM) was seen in the ER for bronchitis a year ago. The CXR showed a right upper lobe (RUL) mass, and the patient was told to follow-up with his physician but he never did.

He now complains of cough productive of yellow sputum for a week and reports some weight loss but he cannot say how much.

Past medical history (PMH)

Smoker, EtOH abuse.

Medications

None.

Social history (SH)

Smoker with a 30 pack-year history, quit 2 weeks ago. He drinks a pint of liquor per day.

Physical examination

A thin man in NAD.
VS 37.7-105-137/61-18.
Chest: breath sounds are reduced in the right upper lobe.
CVS: Clear S1S2.
Abdomen: Soft, NT, ND, +BS.
Extremities: clubbing.


Finger clubbing in a long-term smoker with a suspected lung cancer.

What is the most likely diagnosis?

Pneumonia?
TB?
Lung cancer?

What diagnostics tests would you order?

CXR
CBCD, CMP


CBC shows anemia due to multiple factors: suspected iron deficiency, malnutrition (note that albumin level is 1.8 mg/dL), alcohol abuse and chronic disease.

Chest X-ray


A PA CXR showed a small RUL mass a year ago (left). The patient was advised to follow-up with his physician and to have a CT scan of the chest but he was drinking heavily at the time and never followed up on the findings. A close-up of the RUL mass (middle). The previous CXR report (right) (click to enlarge the images).


The RUL mass seen on the previous CXR a year ago has increased in size (left). The lateral film shows a large RUL mass (middle). The CXR report (right) (click to enlarge the images).

CT of the chest


The CT of the chest shows a RUL mass and mediastinal lymphadenopathy.


CT of the chest.


CT of the chest; A CT report (right).

CT report: There is a large relatively hypodense mass involving much of the right upper lobe and directly abutting the superior mediastinum on the right. The appearance is highly suspicious for upper lobe neoplasm, possibly with associated post obstructive pneumonitis more peripherally. This mass is estimated to measure approximately 8.2 cm A.P. by 5.8 cm transversely while extending for approximately 10 cm cephalocaudally. There is massive mediastinal adenopathy, predominantly in the right paratracheal region. There is further extensive right perihilar adenopathy, not easily demarcated from mass.

There is mild narrowing of the right upper lobe bronchus. There is apparent encasement of the distal main right pulmonary artery by mass/adenopathy. This was not optimally defined on the current study, due to limited enhancement of the right pulmonary artery. Perihilar calcifications are noted bilaterally, suggesting old granulomatous disease. There is evidence of underlying emphysema. There is a very small right pleural effusion.

What happened?

The patient initially agreed to have a diagnostic bronchoscopy but at the beginning of the procedure he refused and was scheduled for a CT-guided transthoracic biopsy.


Antibiotic treatment for post-obstructive pneumonia.

The CT-guided biopsy showed an invasive poorly differentiated non-small cell carcinoma, consistent with poorly differentiated squamous cell carcinoma, tumor necrosis was present. The slides showed a long core of tissue, demonstrating invasive epithelial cell tumor without glandular differentiation. The tumor cells were large and polygonal with large hyperchromatic nuclei with frequent mitosis.

A CT scan of the abdomen and a whole body bone scan will be done for staging of the lung cancer.

Final diagnosis

Post-obstructive pneumonia. Lung cancer.

Summary

Finger clubbing, or digital clubbing is a deformity of the fingers and fingernails that is associated with a number of conditions. Hippocrates was probably the first to document clubbing as a sign of disease, and the phenomenon is therefore occasionally called Hippocratic fingers.


Clubbing of the fingernail. The red line shows the outline of a clubbed nail. Image source: Wikipedia, GNU Free Documentation License.

Clubbing develops in five steps:

1. Fluctuation and softening of the nail bed.
2. Loss of the normal, less than 165° angle (Lovibond angle) between the nailbed and the fold (cuticula).
3. Increased convexity of the nail fold.
4. Thickening of the whole distal (end part of the) finger (resembling a drumstick).
5. Shiny aspect and striation of the nail and skin.

Schamroth's test or Schamroth's window test (originally demonstrated by South African cardiologist Dr Leo Schamroth on himself) is a popular test for clubbing. When the distal phalanges (bones nearest the fingertips) of corresponding fingers of opposite hands are directly apposed (placed against each other back to back), a small diamond-shaped "window" is normally apparent between the nailbeds. If this window is obliterated, the test is positive and clubbing is present.

Schamroth sign is named not only after a physician who described it but also after the patient who happened to be the physician himself.

References

Finger clubbing. James H. Fisher. Merck Manual, 2006.
Clubbing of the Nails: Overview. eMedicine Dermatology, 2008.
Clubbing, from Wikipedia, the free encyclopedia.
The rational clinical examination: does this patient have clubbing? Myers KA, Farquhar DR (2001). JAMA 286: 341–7.
Personal experience. Schamroth L (February 1976). S. Afr. Med. J. 50 (9): 297–300.
A Unique Eponymous Sign of Finger Clubbing (Schamroth Sign) That Is Named Not Only After a Physician Who Described It But Also After the Patient Who Happened to be the Physician Himself. T. Cheng. The American Journal of Cardiology, Volume 96, Issue 11, Pages 1614-1615.
Biography of Leo Schamroth. Heart Rhythm Society.

Related reading

Sir Richard Doll Dies at 92; Linked Smoking to Illnesses - NYTimes 7/05.

Published: 02/01/2004
Updated: 02/09/2009