Digital clubbing as a result of metastatic lung cancer

Article information

Korean J Intern Med. 2022;37(4):883-884

Publication date (electronic) : 2022 March 11

doi : https://doi.org/10.3904/kjim.2022.002

Chelsea Roberts¹, Morteza Khodaee^1,2

¹Department of Family Medicine, University of Colorado School of Medicine, Denver, CO, USA

²Department of Orthopedics, University of Colorado School of Medicine, Denver, CO, USA

Correspondence to: Morteza Khodaee, M.D., Tel: +1-702-848-9056, Fax: +1-720-848-9001, E-mail: Morteza.khodaee@cuanschutz.edu

Received 2021 November 02; Revised 2022 January 04; Accepted 2022 January 04.

A 47-year-old female presented with joint swelling and arthralgias of bilateral hands and feet with fatigue and weight loss. Past medical history included melanoma 8 years ago with a negative sentinel lymph node biopsy. She had significant digital clubbing, confirmed with Schamroth window test (Fig. 1). X-rays revealed a large lung mass and periosteal reaction (Fig. 2). She was ultimately diagnosed with hypertrophic osteoarthropathy (HOA) due to metastatic melanoma.

Figure 1

(A) Clubbing of fingers with periungual erythema, (B) clubbing of the toes, and (C) positive Schamroth window test (lack of window with patient’s clubbed fingers).

Figure 2

(A) Anteroposterior chest radiograph demonstrating a large right lower lobe mass, (B) distal left radius periosteal reaction, (C) clubbing of the distal fingers best seen on lateral view of the right hand (arrowed lines).

Clubbing is important to identify because the differential diagnosis is actually quite limited. Clubbing can be benign and occur with no other findings; otherwise, it is associated with HOA. HOA is a syndrome caused by abnormal skin and osseous tissue proliferation of the extremities. It is diagnosed by digital clubbing, joint effusions, and periosteal reaction on imaging. In most cases, clubbing develops first and may be the only sign of HOA.

Primary HOA is typically hereditary, and accounts for 3% to 5% of HOA cases. Secondary HOA is most often associated with pulmonary etiologies (e.g., lung carcinoma, metastases, pulmonary infections, and chronic lung diseases). HOA is also associated with other intrathoracic causes (e.g., cyanotic heart disease, atrial myxomas, and infective endocarditis). Less commonly, HOA is associated with inflammatory bowel disease and cirrhosis. Localized HOA of one or two limbs can also occur.

Diagnosis of HOA relies on imaging of affected joints; there are no serologic tests. Plain radiographs typically demonstrate soft tissue changes associated with clubbing symmetric periosteal bone reaction in absence of fracture, and preserved joint spaces. If diagnostic uncertainty remains, bone scintigraphy with technetium 99m is more sensitive and the gold standard.

For primary HOA, there are no known treatments, and does not affect life expectancy. Secondary HOA requires further work-up for underlying cause which should include chest imaging, followed by directed treatment. Clubbing can resolve with treatment of underlying pathology.

Verbal informed consent was obtained from patient.