A 53-yr-old woman presented with persistent right shoulder and arm pain for several weeks. On examination, she had a painful arc of motion in the right shoulder without any significant deficit. Neer, Hawkins, and Jobe tests were positive, whereas the biceps provocative test was negative. Magnetic resonance imaging (MRI) of the right shoulder revealed calcific tendinopathy of the subscapularis tendon, characterized by multiple calcifications, the largest measuring up to 12 mm in diameter. Calcifications were observed within the subscapularis tendon and peritendinous soft tissues. They appeared markedly hypointense on T1-weighted and proton density (PD) turbo spin-echo images with spectral attenuated inversion recovery fat suppression. Some of these calcifications migrated distally into the musculotendinous junction and belly of the subscapularis muscle, resulting in significant edema and inflammation. Edema was demonstrated by intense hyperintensity on PD spectral attenuated inversion recovery fat-suppressed images, consistent with an acute exacerbation of calcific tendinopathy. No calcifications were detected in other rotator cuff tendons. Additional MRI findings included degenerative osteoarthritis of the acromioclavicular joint, mild subacromial and subdeltoid effusion, moderate supraspinatus muscle atrophy, and a posterior labral tear with an adjacent glenoid subchondral cyst (Figs. 1–4). The patient was started on conservative treatment, which consisted of rest, nonsteroidal anti-inflammatory drugs, and physical therapy. The patient was informed that if her symptoms did not improve with this approach, surgical options, such as arthroscopic debridement and removal of calcific deposits, may be considered.FIGURE 1: MRI of calcific subscapularis tendinopathy in a 53-yr-old woman. A–D, Sagittal T1-weighted images of the right shoulder demonstrate multiple calcific deposits appearing as marked hypointense signals within and around the subscapularis tendon, extending to the subscapularis musculotendinous junction and the muscle belly (yellow arrows). Acromioclavicular joint osteoarthritis is also present (yellow circles).FIGURE 2: MRI of a calcific subscapularis tendinopathy in a 53-yr-old woman. A–D, Sagittal fat-saturated proton density turbo spin-echo spectral attenuated inversion recovery images demonstrate multiple calcific deposits appearing as marked hypointense signals within and around the subscapularis tendon (yellow arrows), with significant associated edema and inflammation (arrowheads). Acromioclavicular joint osteoarthritis is also present (yellow circles).FIGURE 3: MRI of calcific subscapularis tendinopathy in a 53-yr-old woman. A–C, Coronal fat-saturated PD turbo spin-echo spectral attenuated inversion recovery images demonstrate a large calcific deposit appearing as a marked hypointense signal within and around the subscapularis tendon (yellow arrows), extending into the subscapularis musculotendinous junction and muscle belly, with significant associated edema and inflammation (arrowheads).FIGURE 4: MRI of calcific subscapularis tendinopathy in a 53-yr-old woman. A–D, Axial fat-saturated PD turbo spin-echo spectral attenuated inversion recovery images demonstrate multiple calcific deposits appearing as marked hypointense signals within and around the subscapularis tendon, extending to the subscapularis musculotendinous junction and the muscle belly (yellow arrows). Associated findings include biceps tenosynovitis (arrowheads), a posterior glenoid labral tear, and a paralabral cyst (thick arrow).Calcific tendinopathy is characterized by the deposition of calcium hydroxyapatite crystals within the tendons, most frequently affecting the rotator cuff of the shoulder. The supraspinatus tendon is involved in the majority of cases, whereas subscapularis tendon involvement is uncommon.1,2 Although the condition typically remains confined to the tendon, calcific deposits may occasionally extend into adjacent compartments, most often into the subbursal space, where they can trigger significant inflammation and pain. In rare instances, deposits may migrate into the bone or muscle. Intramuscular extension is an exceptional manifestation that can obscure diagnosis and complicate clinical decision making. Recognition of such atypical imaging patterns is crucial, as they may mimic alternative pathologies and lead to unnecessary investigations.3 MRI provides excellent soft-tissue contrast and multiplanar capability, enabling a detailed assessment of calcific tendinopathy. It demonstrates low-signal calcifications on T1, edema and inflammation on T2, and detects complications such as tendon tears and effusions. These findings offer critical information for accurate diagnosis and effective treatment planning in the future.
Mustafa Kemal Demir (Tue,) studied this question.