Atypical Localization of Calcific Shoulder Tendinopathy: Humeral Insertion of the Pectoralis Major

INTRODUCTION: Calcific tendinopathy of the pectoralis major at its humeral insertion is extremely rare. Few cases have been reported in the literature. We reported a unique case of calcification of the pectoralis major insertion site and conducted a review of the existing literature to propose standardized management. CASE PRESENTATION: We reported a case of a 63-year-old lady, right-handed, non-smoker, homemaker without any history of trauma or symptoms suggestive of para-neoplasia syndrome. For 1 month, the patient presented severe, disabling pain of the left shoulder which occurred spontaneously, usually in the morning and after effort. The patient had painful passive terminal adduction and internal rotation. There was no neurovascular deficiency. Magnetic resonance imaging and computed tomography (CT) scan helped diagnose the calcific tendinopathy at the pectoralis major humeral insertion. Non-surgical management was performed, combining physiotherapy and painkillers. Two months’ control, CT scan reported complete calcification resorption. The biologic assessment revealed hyperparathyroidism. CONCLUSION: This rare and atypical localization can mislead the surgeon. A biological assessment to research a systemic etiology is mandatory and standardized. A biopsy is not required, radiological examinations are sufficient. Surgical treatment may be proposed in specific cases to shorten the necessary rehabilitation time.