Pancytopenia and secondary myelofibrosis could be induced by primary hyperparathyroidism.

Hyperparathyroidism may be a precipitating factor important to the development of myelofibrosis: however, there has been only a few reports regarding myelofibrosis secondary to primary hyperparathyroidism. Recently, a rare case of pancytopenia caused by myelofibrosis in a 41-year-old woman who complained of general weakness and arthralgia presented to our clinical service. The patient was diagnosed with primary hyperparathyroidism with pancytopenia. Bone marrow biopsy revealed myelofibrosis. Right parathyroidectomy was performed and a parathyroid adenoma was totally excised. After surgery, the CBC counts and other clinical abnormalities gradually improved without further intervention. We concluded that the pancytopenia was because of bone marrow fibrosis resulting from primary hyperparathyroidism. Therefore, physicians should consider myelofibrosis secondary to primary hyperparathyroidism as a cause of pancytopenia in hypercalcemic patients, even though it is rare.