CASE 9606 Published on 05.11.2011

Calcific tendonitis of pectoralis major

Section

Musculoskeletal system

Case Type

Clinical Cases

Authors

Revelli M, Paparo F, Piccazzo R, Migone S, Muda A, Garlaschi G

Università degli Studi di Genova, Sezione di Diagnostica per Immagini
Patient

53 years, female

Categories
Area of Interest Musculoskeletal system ; Imaging Technique MR, CT, Digital radiography
Clinical History
A 53-year-old woman presented to our institution with several months history of spontaneous pain in the left upper arm; there was no history of trauma. Clinical examination revealed a restricted range of movement. The past medical history revealed malignant melanoma 10 years ago. Blood tests were normal.
Imaging Findings
An anteroposterior radiograph of the chest revealed a radiopaque image in the right humeral diaphysis (Fig. 1); this finding could be more precisely localized with a targeted examination, using a correct positioning with an oblique incidence.
The patient underwent an MRI examination: on Fat-Sat T2-weighted sequences we observed an area of inhomogeneous high signal intensity, with ill-defined margins, in the bone marrow of the humeral diaphysis(Figs. 2-3) The imaging findings were suspect for bone neoplasm, and a CT examination was performed. Computed tomography revealed a calcification along the distal tendon of pectoralis major muscle, with associated minimal cortical erosion at its attachment (Figs. 4-5).
Discussion
Calcific tendonitis is a common disorder caused by calcium hydroxyapatite; it could involve any joint, however it typically affects the shoulder and the hip. The pathogenesis of calcium hydroxyapatite crystal deposition in a tendon is unclear. The most accredited theory is that calcific tendonitis is a primary disorder in susceptible tendons: it suggests the presence of a critical zone, whose poor oxygenation in certain circumstances can trigger a focal metaplasia, with transformation of the tendon into fibrocartilage and subsequent deposition of calcium [1].
The presentation is usually acute and symptoms may include erythema, swelling, painful range of motion and fever due to an inflammatory reaction. Although osseous involvement associated with calcific tendonitis has been reported, it is unusual despite the high incidence of calcific tendonitis [2].
Radiographic examination is usually necessary to diagnose calcific tendonitis, though tangential radiographs of the affected cortex are required to detect the calcifications and their association with cortical or marrow involvement. The “comet-tail” appearance of the calcifications [3] can help to confirm their intratendinous location.
CT achieves better results in detection of cortical erosion and soft-tissue calcification; CT should be considered as the preferred imaging modality to depict the continuity of the tendinous, cortical and medullary processes. MRI allows a more precise evaluation of the bone marrow involvement, but calcification in the adjacent tendon may not be appreciated, leading to the wrong concern of neoplasm.
Ultrasound can be useful to study calcific tendonitis; in our case the patient didn’t underwent an US evaluation because the diagnosis has been already achieved with other modalities.
The differential diagnosis of calcific tendonitis includes traumatic avulsion of the pectoralis major tendon and neoplastic processes, such as chondrosarcoma or other chondroid matrix producing neoplasm; the characteristic location of involvement in and near the major tendon attachments (usually easily detectable with US), as well as the lack of a discrete soft-tissue mass and the bilateral involvement by calcific tendonitis may be important observations in excluding neoplasm [2].
Treatment of calcific tendonitis is usually limited to the use of non-steroidal anti-inflammatory drugs [4].
Differential Diagnosis List
Calcific tendonitis of pectoralis major
Neoplastic process
Traumatic avulsion
Final Diagnosis
Calcific tendonitis of pectoralis major
Case information
URL: https://www.eurorad.org/case/9606
DOI: 10.1594/EURORAD/CASE.9606
ISSN: 1563-4086