Severe Facial Disfiguration Due to Uremic Leontiasis Ossea from Underlying Secondary Hyperparathyroidism

Renal osteodystrophy is a common complication of end-stage renal disease (ESRD) patients. Rarely, it can be associated with uremic leontiasis ossea (ULO) that is characterized by progressive enlargement of the facial bones and is thought to be secondary to uncontrolled secondary hyperparathyroidism (sHPTH) in the setting of ESRD. Few case reports have been described in the literature with our case appearing to be the most severe. Due to the rarity of this disease, there is no current standard of treatment.

Case Description:

The patient is a 28‐year‐old male with ESRD of unknown etiology on hemodialysis since childhood, uncontrolled sHPTH, and severe osteoporosis with a fragility femoral fracture, who developed marked facial disfiguration due to progressive ULO. His ULO was associated with difficulty speaking, oral intake, and facial pain with progressive worsening over a year. On physical exam, maxillary and mandibular facial bones enlargement, nasal bridge flattening, nares widening, increased interdental spacing, and inability to close the mouth have been noted.

The biochemical workup showed persistent hyperphosphatemia, hypocalcemia, and elevated PTH up to 3687 pg/dl. Axial computed tomography with coronal and sagittal reformats showed characteristic changes for HPTH such as thinning/loss of the inner and outer cortical bone, lytic and sclerotic changes of visualized osseous structures (so-called “salt and pepper patter”) more prominent involving the facial bones and osseous enlargement/expansion, especially of the maxilla and mandible bones. This results in progressive significant facial distortion, prognathism, and narrowing of the paranasal sinuses, nasal and oral cavities. Of note, initial facial CT, done 3 years before clinical changes, did not show bone abnormalities. DEXA study was remarkable for Z score of -5.5 in forearm and -5.0 in spine.

The patient underwent three parathyroid gland parathyroidectomy with PTH drop from 3681 to 642 pg/ml following surgery with clinical improvement of the facial symptoms after surgery within a month.

Discussion:

ULO is a rare type of osteodystrophy that may result in life threatening upper airway obstruction and compressive cranial neuropathy. Based on this case presentation, ULO can develop relatively rapidly (within 12 months) in patients with long standing HPTH and it can be prevented by correction of metabolic abnormalities and HPTH control. In patients with long standing uncontrolled HPTH, periodic facial imaging could be considered for early detection of ULO and prevention related complications.