Osteitis fibrosa cystica recovery following parathyroidectomy for primary hyperparathyroidism: a case series and review of literature.

Osteitis fibrosa cystica (OFC) is an extreme manifestation of accelerated bone resorption in primary hyperparathyroidism (PHPT), rarely encountered nowadays. Bone mineral density gain following parathyroidectomy (PTx) is well documented, while little is known regarding the timeline of lytic lesions remineralization and recovery. We present three patients with OFC, surgically treated for PHPT, with clinical, biochemical, and advanced radiological (CT or MRI) post-PTx follow-up. Additionally, we review published OFC case reports that include serial imaging of bony lesions following PTx. All patients received calcium, magnesium and alphacalcidiol supplementation post-PTx with serum calcium, PTH, and alkaline phosphatase gradually normalizing. Patients 1 and 2 exhibited an impressive remineralization of pelvic lytic lesions within 6 and 12 mo following PTx, respectively. Patient 3 showed partial remineralization of C4-C5 vertebrae at 6 mo, with continued improvement at 18 mo post-PTx. Both Patients 1 and 3 required salvage orthopedic intervention. We summarize reports of 54 patients with PHPT and OFC, assessed for lytic lesion recovery after PTx using various imaging modalities. Most lesions showed partial remineralization within 6-12 mo. Near full and complete remineralization was evident in 38 (70.3%) of the patients on the last imaging follow-up. Substantial remineralization of lytic lesions in OFC can be observed within months of PTx, even in large or symptomatic lesions. This early skeletal recovery may obviate the need for orthopedic intervention in selected patients and supports a conservative management approach when lesion location permits.