2025 Volume 45 Issue 8 Pages 362-369
Chronic expanding hematoma (CEH) is characterized by a hematoma that persists and gradually enlarges over more than one month, with hemorrhagic diathesis recognized as a contributing factor. To date, no cases of CEH associated with idiopathic thrombocytopenic purpura (ITP) have been reported. Although rare, CEH may rupture. Herein, we present a case of CEH that developed at a surgical site and ruptured in a patient with ITP. A 53-year-old woman, who underwent buttock surgery and was diagnosed with ITP at the ages of 16 and 33, respectively, noticed a mass in her left buttock 15 years prior. The mass progressively enlarged and ruptured. Following surgical removal, CEH diagnosis was established based on medical history taking, imaging, and pathology. The involvement of ITP in the development of CEH was suggested, emphasizing the importance of distinguishing CEH from soft tissue malignancies. When evaluating soft-tissue masses, CEH should be included in the differential diagnosis, with careful consideration of the patient's medical history.