Aromatase Inhibitor-Associated Distal Radioulnar Joint Instability and Tear of the Extensor Digiti Minimi: A Case...

Area of Science:

• Oncology
• Rheumatology
• Musculoskeletal Imaging

Background:

• Aromatase inhibitors (AIs) are crucial for treating postmenopausal estrogen receptor-positive breast cancer, improving outcomes.
• However, AIs can cause musculoskeletal adverse effects, termed aromatase inhibitor-associated musculoskeletal syndrome (AIMSS).
• AIMSS commonly presents as arthralgia, myalgia, bone loss, and tendinopathy, particularly affecting the hand and wrist.

Observation:

• A 72-year-old breast cancer survivor on an AI presented with chronic dominant wrist pain, weakness, and a dropped 5th finger.
• This presentation suggested a complication of AIMSS.
• The affected joints in AIMSS are typically the hand and wrist, with symptoms including symmetric arthralgia, stiffness, and tendinopathy.

Findings:

• Diagnostic musculoskeletal ultrasonography revealed an extensor digitorum minimi tendon tear.
• Radioulnar joint subluxation was also identified.
• This specific combination of radioulnar joint subluxation and extensor tendon tear has not been previously reported in AIMSS.

Implications:

• This case underscores the importance of recognizing a broader spectrum of AIMSS pathologies beyond common symptoms.
• In-office ultrasonography combined with dynamic examination is a valuable tool for diagnosing underrecognized AIMSS complications.
• Early and accurate diagnosis of these musculoskeletal issues can improve treatment tolerability and quality of life for breast cancer survivors on AIs.