Osteitis Fibrosa Cystica; A Forgotten Manifestation of Secondary Hyperparathyroidism Due to End-Stage Renal Disease: A Case Report

INTRODUCTION: Osteitis fibrosa cystica is a rare complication of secondary hyperparathyroidism. Even though it is thought to be a disease of the past, it still continues to be seen in this modern era in the setting of undiagnosed or untreated chronic kidney disease. CASE PRESENTATION: A 26-year-old married Ethiopian women presented with 4 year history of progressive proximal weakness of extremities and diffuse bone pain. Physical examination revealed diffuse bone tenderness and features consistent with myopathy. Blood work up showed raised creatinine, markedly elevated PTH, borderline low calcium, and vitamin D in severe deficiency range. X-Ray findings were consistent with classical skeletal lesion of severe secondary hyperparathyroidism. CONCLUSION: Osteitis fibrosa cystica is a rare but still frequent complication of secondary hyperparathyroidism, which may be the initial presentation of chronic kidney disease. This case report emphasizes the importance of considering secondary hyperparathyroidism in patients presenting with weakness and bone pain to allow for early diagnosis, treatment, and improvement of overall prognosis.