ABSTRACT
BACKGROUND: Although the skeleton remains a common target of primary hyperparathyroidism, the classic bone disease "osteitis fibrosa cystica" is currently rare due to early diagnosis. This case represents severe classic bone manifestations of primary hyperparathyroidism due to delayed diagnosis and delayed medical attention. CASE PRESENTATION: A 19-year-old young female was symptomatically managed for chronic back pain and nonspecific bone pain in the small joints of both hands over 2 months by a general practitioner. The patient had delayed seeking for treatment for 3 months. Later, she was evaluated for tuberculosis, hematological malignancies and rheumatic disorders following a fractured T12 vertebra and underwent pedicle screw fixation. However, clinical examination and investigations, including biochemistry, imaging and histology, ruled out the above conditions. Unfortunately, serum calcium level was not performed at the initial presentation. Later, primary hyperparathyroidism was diagnosed on the basis of moderate hypercalcaemia and elevated intact PTH levels (2064 pg/ml). She had sufficient vitamin D levels and normal kidney function. Her DXA scan revealed severe secondary osteoporosis with the lowest Z score of -8 at the total lumbar spine. Ultrasonography of the thyroid revealed a hypo echoic mass in the left lower neck, and localization studies with technetium-99 m sestamibi and 4D-CT revealed a left inferior parathyroid adenoma (1.6 × 1.5 × 1.6 cm). CT scan also revealed brown tumors in the mandible and vertebrae and diffuse bony changes in the skull, sternum, humerus and vertebrae. Her radiographs revealed subperiosteal bone resorption on the radial aspects of the middle and distal phalanges and brown tumors in both the ulna and fibula. We excluded MEN and other hereditary syndromes in our patient with a personal and family history and with a normal pituitary hormone profile because of poor resources for genetic testing. She underwent parathyroid adenoma excision, and the postoperative period was complicated with hungry bone syndrome, requiring high doses of calcium and active vitamin D supplements. These supplements were gradually weaned off over 6 months, and she recovered with normal biochemical investigations. Histology revealed parathyroid adenoma without malignant features. CONCLUSION: In developing countries where routine calcium screening is not available, clinicians should be aware of various manifestations of primary hyperparathyroidism to allow diagnosis as soon as possible without delay to prevent further progression, as it is a treatable condition.