Digital Clubbing in a Patient with Bronchogenic Carcinoma

Figure 1

Figure 2

A 45-year-old man presents with a 1- to2-week history of low-grade fever and nonproductivecough. He has a long history of cigarette and alcoholabuse. The office nurse expresses her concern about thepatient's cyanotic nail beds and requests your immediateevaluation.

Which of the following most accurately describes thepatient's condition?

• Chronic paronychia.

• Hypothyroidism.

• Clubbing.

• Chronic obstructive pulmonary disease.

Figure A

Figure B

DISCUSSION:

A clinical syndromeof unknown cause,

clubbing

was firstdescribed by Hippocrates some 2500years ago. Significant clubbing is usuallyclinically obvious; it is characterizedby enlargement of the terminaldigital phalanges of the fingers (FigureA) or toes (Figure B), with loss ofthe normal 15-degree nail-bed angle(the angle between the proximal nailand the cuticle). Clubbing is present ifthe ratio of the anteroposterior diameterof the finger at the nail bed to theanteroposterior diameter at the distalinterphalangeal joint is greater than1:1. Schamroth test may also indicatethe presence of clubbing (Box).This condition may be clinicallyconfused with a variety of other conditions, including hypothyroidism, infectionsof the terminal phalanges,chronic paronychia, and exaggeratedcurvature of the nails (as seen insome African Americans).Clubbing suggests the presenceof a significant occult illness, suchas pulmonary disease, inflammatorybowel disease, liver disease, or cyanoticcongenital heart disease. (Thispatient had bronchiogenic carcinoma.)Among patients with pulmonarydisease, clubbing is a common manifestationof lung tumors and chronicseptic conditions, such as lung abscessor bronchiectasis. Arteriovenousfistulas in the lung that causeshunting may also result in clubbing.Although clubbing has been reportedin patients with benign fibromas ofthe lung and pleura, tumors associatedwith clubbing are usually malignant.Finger clubbing is uncommonin patients with chronic obstructivepulmonary disease or chronicpulmonary tuberculosis.Laboratory evaluation may includea variety of screening tests, includingcomplete blood cell count;fecal blood screening; ECG; and pulmonary,liver, and thyroid functiontests. The most important screeningtest, however, is chest radiography.Treatment is directed at the underlyingpathology. More advancedcases may be associated with a burningsensation in the fingertips, jointpain, and severe pain when the affectedlimbs are moved. These secondarysymptoms must also be addressed.

References:

REFERENCES:1. Lampe RM, Kagan A. Detection of clubbing-Schamroth’s sign: closing the window and openingthe angle. Clin Pediatr. 1983;22:125.
2. Schamroth L. Personal experience. S Afr MedJ. 1976;50:297-300.

FOR MORE INFORMATION:

• Saab BR, Kanaan NV. Clubbing: a tip-off to underlyingdisease. Geriatrics. 1998;53:54-57.
• Schneiderman H. Digital clubbing due to idiopathicpulmonary fibrosis. Consultant. 1996;36:1249-1256.