Abstract Introduction Mediastinal masses are rare growths that can be benign or malignant. Depending on the location of the mass within the thorax, differentials can be narrowed. We describe an interesting case of a patient with a relatively benign history who presented with a posterior mediastinal mass. Description We present a 44-year-old woman with a history of thalassemia on hydroxyurea who presented with palpitations for three days. In the ED, vital signs revealed sinus tachycardia. Physical exam noted abdominal masses suspicious for splenomegaly. Initial work-up was significant for pancytopenia: WBC 1.8, Hgb 4.3, Plt 39 ANC 0.47. Chest x-ray revealed a lobulated marginated mass-like structure projecting over the right lung. CT Chest noted multiple bilateral paraspinal soft tissue masses with a dominant lesion in the right lower chest. Bilateral adnexal masses were additionally noted, with features suspicious for neoplasm. Initial work-up for pancytopenia was negative for infectious etiologies. Tumor markers including CEA, CA19-9, and CA 125 were normal. She underwent bone marrow biopsy which is pending at this time. Upon discussion with her outpatient hematologist, he reported she had history of extramedullary hematopoiesis of the spleen. Throughout her course, she remained clinically stable without fever, chest pain, or shortness of breath despite remaining pancytopenic. Discussion Differentials for posterior mediastinal masses include neurogenic tumors, lymphoma, and rarely, extramedullary hematopoiesis (EMH). This patient presented with posterior EMH because of bone marrow failure from unknown causes. However, arrival at this diagnosis was prolonged due to limited history. On imaging, she was noted to have adnexal masses concerning for malignancy, however hepatosplenomegaly was not noted on radiographic report despite physical exam findings of abdominal masses. This alerted our team to the possibility of intrathoracic extramedullary hematopoiesis. Her case is additionally complicated by her history of thalassemia, which prior to her presentation was well managed and relatively benign. She previously only required one prior pRBC transfusion during an uncomplicated surgery. Diagnosis required careful questioning of the patient’s history of anemia and hematology, imaging, and coordination with her outpatient specialists. Further work-up is still pending on this patient, however a suspicion of malignancy versus bone marrow disorder is the leading differential for the cause of thoracic development of EMH. Surgical resection is the main treatment modality, and final recommendations are pending for our patient. This abstract is funded by: None
Ali et al. (Fri,) studied this question.