[Isolated bone marrow mastocytosis: a rare cause of osteoporosis not to be missed].

Osteoporosis can be secondary to other diseases. Among these, mastocytosis is easily recognized when typical skin lesions and systemic symptoms are present. When mastocytosis is confined to bone, as in our case, diagnosis is based on the presence in the bone marrow of an increased number of mastocytes with a nodular arrangement near the bone trabeculae. The diagnosis has to be suspected when severe vertebral and peripheral osteoporosis occurs in middle aged people, especially men. Bisphosphonates are the most frequently applied treatment but their efficacy is limited. Early diagnosis is recommended because the use of several drugs, including fluoride, which is frequently used in osteoporosis.