Cyclical Thrombocytopenia Synchronized With the Patient's Menstrual Cycle Treated With Danazol.

Cyclical thrombocytopenia (CTP) is a very rare condition and often misdiagnosed as immune thrombocytopenia (ITP) due to similar features existing between the two. When evaluating a patient for the possible diagnosis of ITP, CTP must be high on the differential diagnosis. The main difference between the two conditions is that CTP is usually unresponsive to the treatment given to ITP and will ultimately display a cyclical nature with periods of low, normal and elevated platelets. As of date, there are only 70 cases in the literature. However, this number may be misrepresented due to the difficulty in diagnosis. The authors report a case of a 36-year-old woman who was misdiagnosed with ITP and underwent unnecessary treatment with corticosteroids, rituximab, intravenous immunoglobulins, and a splenectomy. A diagnosis of CTP was made after extensive review and the authors aim to bring awareness of this uncommon condition.