Extramedullary Hematopoiesis Mimicking Presacral Nodes in Carcinoma Endometrium

This case report describes a rare presentation of extramedullary hematopoiesis (EMH) mimicking presacral nodal metastasis in a 61-year-old postmenopausal woman diagnosed with endometrial carcinoma. The patient presented with 1 month of postmenopausal bleeding and chronic dull back pain, without any significant prior medical or surgical history. Transabdominal and transvaginal ultrasound revealed endometrial hyperplasia, while magnetic resonance imaging (MRI) identified a left fundal endometrial lesion with less than 50% myometrial invasion and multiple presacral soft tissue nodules. Notably, bone marrow reconversion was also observed. The presacral nodules demonstrated imaging characteristics consistent with EMH, a phenomenon defined by the presence of hematopoietic tissue outside the bone marrow, typically arising in response to ineffective erythropoiesis or increased erythrocyte destruction. While commonly involving the liver, spleen, or paraspinal regions, presacral EMH is exceedingly rare and often poses diagnostic challenges due to its ability to mimic neoplastic lesions. A thorough review of the patient's hematologic status revealed severe anemia that could explain the development of EMH. The imaging findings, in conjunction with clinical context, were crucial in differentiating EMH from other presacral masses such as chordoma, lymphoma, neurogenic tumors, or metastatic disease. Accurate identification of EMH is essential, as management strategies differ significantly from those for malignant neoplasms. EMH is generally asymptomatic and does not require treatment unless symptomatic, in which case options include radiotherapy, blood transfusion, iron chelation, and, in select cases, surgery. In this patient, EMH presented incidentally secondary to severe anemia caused by severe postmenopausal bleeding. This case underscores the importance of considering EMH in the differential diagnosis of presacral masses, particularly in patients with known malignancy, as misinterpretation may lead to unnecessary invasive procedures or overtreatment. MRI remains the imaging modality of choice for characterizing EMH. Early and accurate recognition of EMH can significantly impact patient management and prognosis.