. Destructive Bone Lesion in a Eucalcemic Patient with Primary Hyperparathyroidism. OrthopaedicsOne Cases. In: OrthopaedicsOne - The Orthopaedic Knowledge Network. Created Aug 28, 2011 08:43. Last modified Jul 18, 2012 13:10 ver.8. Retrieved 2019-08-18, from https://www.orthopaedicsone.com/x/UgD8Aw.
This case report underscores the importance of a workup for multiple myeloma (MM) in a patient with persistent and new bone lesions following parathyroidectomy for primary hyperparathyroidism (PHPT).
Although PHPT and MM are two of the most common causes of hypercalcemia in the adult population, the co-existence of both diseases remains rare. In all published cases of concurrent disease, suspicion for a second metabolic or malignant process was raised by persistent or recurrent hypercalcemia despite medical therapy.
We report the first case of a pathologic fracture leading to the diagnosis of MM in a eucalcemic patient with history of parathyroidectomy for PHPT. Persistent and new bone lesions following parathyroidectomy, despite normalized serum parathyroid hormone (PTH) and calcium levels, raised clinical suspicion for MM.
The patient is a 51-year-old female who was referred to our orthopaedic oncology clinic for evaluation of a left humerus fracture-nonunion following minor trauma 6 months prior to presentation. She sustained the injury while bracing herself with her non-dominant left hand to regain her balance after a misstep. She was managed non-operatively in a sling with persistent arm pain precluding participation in physical therapy.
Her medical history included primary hyperparathyroidism (PHPT) with osteitis fibrosa cystica and numerous painful brown tumors, for which she had undergone parathyroidectomy approximately 13 years earlier. Post-parathyroidectomy laboratory studies revealed normalization of her calcium and parathyroid hormone (PTH) levels.
Physical examination of the left upper extremity revealed intact skin with diffuse swelling, tenderness to palpation about the upper arm, and a painful range of shoulder motion with a palpably flail upper arm segment. The arm was well perfused with intact neurologic examination. Laboratory studies revealed a normal serum calcium of 10.4 mg/dL and an elevated phosphorus of 9.0 mg/dL.
Radiographs revealed a fracture through an extensive lytic lesion involving the proximal humerus, with bony changes observed in the scapula and clavicle (Figure 1). A skeletal survey revealed classic findings of PHPT, including numerous brown tumors about her pelvis and subperiosteal bone resorption about her phalanges (Figures 2–3). Radiographs of the left humerus taken at an outside facility 6 years prior to presentation were reviewed showing normal bony anatomy at the level of the current pathologic fracture (Figure 4), confirming the interim development of a new lytic bone lesion. Serum and urine protein electrophoresis and immunohistochemical analyses were negative for monoclonal light chain expression.
MRI and bone scan were obtained to better characterize the lesion, revealing heterogeneous signal intensity with moderate uptake on post-gadolinium imaging (Figure 5) and intermediate to high peripheral signal intensity (Figure 6), respectively. An open biopsy was performed (Figures 7a-b), revealing hypercellularity with uniform sheets of round blue cells containing eccentric nuclei, rare mitotic figures; there was no evidence of blastic or atypical features (Figure 7a). Immunohistochemical analysis revealed positive staining for CD138 (Figure 7b).
A bone marrow aspirate was performed revealing hypercellular areas of marrow with trilineage hematopoiesis and similarly appearing uniform sheets of round blue cells occupying approximately 70% of the marrow cellularity and staining positive for CD138, negative for CD56, and negative for kappa and lambda. The history, physical examination, imaging, and histologic findings were most consistent with non-secretory plasmacytoma of multiple myeloma.
The patient underwent intralesional excision and intramedullary nail fixation augmented with zoledronic acid impregnated poly(methylmethacrylate) (PMMA) (Figure 8).
At the 2-week post-operative visit, she had significant improvement in pain and function. The medical oncologists initiated treatment with dexamethasone, melphalan, and lenalidomide and consultation with a radiation oncologist was made for radiation therapy to the left humerus.
At the 2-month post-operative visit, the patient was pain free and demonstrated active forward flexion of the left shoulder to 70 degrees with 4/5 strength in deltoid and rotator cuff musculature.