Complete Reversal of Bone Marrow Fibrosis after Parathyroidectomy for Secondary Hyperparathyroidism

A 17-year-old man was referred for a haematology consultation because of pancytopenia. On physical examination, he had marked pallor and massive hepatosplenomegaly. He was on haemodialysis because of chronic renal failure of undetermined aetiology, diagnosed 4 years earlier. In the previous 3 years, he had become dependent on monthly blood transfusions, despite using erythropoietin. Ferritin level was 1500 μg/l and a full blood count showed pancytopenia (Hb 54 g/l, WBC 2·1 × 109/l, platelet count 57 × 109/l). A blood film showed teardrop poikilocytes, a few mature erythroblasts and neutropenia. Parathyroid hormone (PTH) level was 3027 ng/l (reference range, 15·0–68·3). An initial bone marrow aspiration was a dry tap; the second attempt yielded a hypocellular sample with several osteoclasts and osteoblasts. A trephine biopsy showed increased bone remodelling with fibrosis (top left, white arrow), osteosclerosis, new bone formation and bone reabsorption, increased osteoclasts and osteoblast rimming (top left, black arrow). Increased diffuse coarse reticulin was confirmed by silver staining (top right). Cytogenetic/molecular tests for JAK2 V617F and BCR-ABL1 rearrangement were negative. The possibility of renal osteodystrophy and myelofibrosis due to secondary hyperparathyroidism was considered. A total parathyroidectomy was performed and an implant of the gland was inserted in the patient's forearm. The biopsy showed hyperplasia of parathyroid glands. Six months after surgery, the patient reported major improvement, with weight gain and no transfusion requirement in that period. Hepatosplenomegaly had disappeared, PTH was 50·0 ng/l, ferritin <1000 μg/l, Hb 83 g/l, WBC 4·7 × 109/l and platelet count 102 × 109/l. Bone marrow aspirate and trephine biopsy showed a complete reversal of fibrosis (bottom). Myelofibrosis resulting from hyperparathyroidism is uncommon. The mechanism is likely to be multifactorial. Haematologists should be aware of this condition, as the differential diagnosis is primary myelofibrosis and other causes of secondary myelofibrosis. More importantly, as parathyroidectomy can lead to a reversal of fibrosis, prompt recognition of this condition has major implications for treatment.