Parathyroid cancer: An update.

Parathyroid cancer (PC) is a rare malignant tumor which comprises 0.5-5% of patients with primary hyperparathyroidism (PHPT). Most of these cancers are sporadic, although it may also occur as a feature of various genetic syndromes including hyperparathyroidism-jaw tumor syndrome (HPT-JT) and multiple endocrine neoplasia (MEN) types 1 and 2A. Although PC is characterized by high levels of serum ionized calcium (Ca) and parathyroid hormone (PTH), the challenge to the clinician is to distinguish PC from the far more common entities of parathyroid adenoma (PA) or hyperplasia, as there are no specific clinical, biochemical, or radiological characteristic of PC. Complete surgical resection is the only known curative treatment for PC with the surgical approach during initial surgery strongly influencing the outcome. In order to avoid local recurrence, the lesion must be removed en-bloc with clear margins. PC has high recurrence rates of up to 50% but with favorable long-term survival rates (10-year overall survival of 60-70%) due to its slow-growing nature. Most patients die not from tumor burden directly but from uncontrolled severe hypercalcemia. In this article we have updated the information on PC by reviewing the literature over the past 10 years and summarizing the findings of the largest series published in this period.

Using 3D computer planning for complex reconstruction of mandibular defects.

For complex reconstruction of osseous defects of the head and neck, three-dimensional (3D) computer planning has been available for over 20 years. However, despite its availability and recent refinements, it is a technology that has not been widely adopted. While 3D computer planning has been proposed to improve surgical precision, reduce operating time and enhance functional outcomes, the objective evidence supporting these claims is limited. Here we review the recent literature that supports the use of 3D computer planning for complex osseous defects of the mandible. We highlight a case example where 3D modeling played a critical role, particularly during the virtual surgical planning stage. Finally, we propose that routine post-operative 3D analysis become an essential element in determining operative success. Critical evaluation of outcomes will better define its use in complex reconstruction of osseous defects.