Fracture Due to Hypercalcemia of Benignancy From a Parotid Tumour

Abstract

Pseudo-arthrosis of the proximal humerus is an uncommon condition that is difficult to treat. Humoral hypercalcemia from a benign tumour is a rare clinical entity and pleomorphic adenoma as its source has never been reported in the literature. We present the case of a 53-year-old gentleman with a pleomorphic parotid gland adenoma and pseudoarthrosis non-union of the proximal humerus exacerbated by symptomatic parathormone-independent hypercalcemia. The non-union is fixed using a novel technique of placing an ipsilateral cortico-cancellous iliac strut graft as a medial buttress and stabilized with a fixed-angle plate over the lateral side. Following the surgical resection of the tumour, hypercalcemia resolved and the patient improved clinically. This case is a good example of a rare endocrine disease managed by a multidisciplinary approach.

Keywords: benignancy; hypercalcemia; nonunion; pleomorphic adenoma; proximal humerus.

Figure 1. Pre-operative X-ray

Figure 2. Showing the medially placed iliac bone graft, tension sutures from the rotator cuff, and lateral fixation with a plate.

Figure 3. Post-operative X-ray showing union and callus.

Figure 4. Histopathology shows myoepithelial cells along with tubular and acinar structures in a chondromyxoid background.

Figure 5. Immunohistochemistry shows diffuse non-homogenous cytoplasmic immunostain in the myoepithelial and epithelial components of the tumour.