In France, a 48-year-old male, new immigrant, known case of end-stage renal disease presented to the emergency room with complaints of difficulty in breathing. He has a 10-year history of hemodialysis. Physical examination revealed a prominence over the mandible and thoracic kyphosis. Bilateral crackles were heard on auscultation of the lungs.
Blood tests showed the following results:
- Calcium level – 1.9 mmol per litre (normal range, 2.2 to 2.6 mmol per litre)
- Phosphate level of 0.96 mmol per litre (normal range, 0.81 to 1.58 mmol per litre)
- 25-hydroxyvitamin D level of 13 nmol per litre (normal range, 75 to 175 nmol per litre)
- Parathyroid hormone level of 4081 ng per litre (normal range, 11.5 to 78.4)
Hypertrophy of the mandible and a heterogenous bony appearance was visible on computed tomography (Panel A) and three-dimensional reconstruction (Panel B) of the face. Both cystic lesions and osteolysis were observed on the imaging studies. Spine, iliac bone, and femur were involved.
Considering his test results, a diagnosis of Osteitis fibrosa cystica was made due to hyperparathyroidism secondary to chronic renal failure.
Hemodialysis was restarted and he was treated with cinacalcet (a drug that increases the sensitivity to calcium) and vitamin D supplements.
At the 6-month follow-up, marked improvement was seen in blood reports with normal vitamin D levels and the PTH levels dropped to 1743 ng per litre, but the bone lesions had not regressed.
When even one of the parathyroid glands makes excessive amounts of parathyroid hormone, the condition is called hyperparathyroidism. But the question arises
Why would the gland produce excessive amounts?
Either autonomous production (primary hyperparathyroidism) or like in the case above: when the calcium levels are insufficient in the blood, parathyroid glands are triggered to compensate by producing more PTH, which can then act on the bones and release calcium to make up for the low blood calcium. This is secondary hyperparathyroidism.
The patient in the discussion here had chronic renal failure, therefore low vitamin D levels which subsequently resulted in low blood calcium levels. Low calcium levels in the blood triggered his parathyroid gland to release PTH which then acted on the bones resulting in osteitis fibrosa cystica, painful lytic lesions, and enlarged bony masses.
Osteitis fibrosa cystica is not a malignancy, although it is aggressive locally, its appearance may be deceptive!
It is a rare condition and a manifestation of advanced hyperparathyroidism. Although skeletal deformity may be the only manifestation too.
Usually, hyperparathyroidism is detected earlier by the high blood calcium levels and associated symptoms such as kidney stones, constipation, fractures, abdominal pain, nausea, peptic ulcers, and weight loss.
‘Bones, stones, abdominal groans and psychic moans”
Management of osteitis fibrosa cystica is largely dependant upon the underlying cause. If the parathyroid gland is an autonomous culprit, it can be surgically removed. If the cause of OFC is secondary hyperparathyroidism, address the underlying pathology, like chronic renal failure in the case in the discussion here.
Drugs such as calcimimetics are alternative to surgical approach or can be given as adjunctives. These drugs enhance the calcium-sensing capability of the parathyroids or in other words trick the glands by mimicking as calcium. Besides, hydration, phosphate binders, vitamin D analogs and a short course of bisphosphonates are the other options to explore.
Earlier the diagnosis of hyperparathyroidism, lesser the destruction and lower chances of OFC
Andre Ramon, M. a.-E. (2020, March 12). Osteitis Fibrosa Cystica. Retrieved from The New England Journal of Medicine: https://www.nejm.org/doi/full/10.1056/NEJMicm1907828
D. JORDI GOLDSTEIN, B. M. (2001). BONE DISEASE. In Nutrition and Renal Disease.
Saleem, M., & Iftikhar, H. (2019). Stones, Bones, Groans, and Psychic Moans: Primary Hyperparathyroidism Presenting as Surgical Emergency. Cureus, 11(6), e4989. https://doi.org/10.7759/cureus.4989
Lee, J. H., Chung, S. M., & Kim, H. S. (2013). Osteitis fibrosa cystica mistaken for malignant disease. Clinical and experimental otorhinolaryngology, 6(2), 110–113. https://doi.org/10.3342/ceo.2013.6.2.110