Two Cases of Extramedullary Hematopoiesis in the Endometrium

Abstract

Endometrium is an extremely rare location for extramedullary hematopoiesis. To our knowledge, only handful case reports/reviews have been published. Here we report two additional cases. Case 1 is a 54-year-old white female who presented with postmenopausal vaginal bleeding. Her medical history was significant for malignant paraganglioma status post resection, benign pulmonary nodules, gastric leiomyoma, and morbid obesity. Her last Pap smear, mammogram, and colonoscopy were up to date and normal. No organomegaly was found on physical exam. The endometrial biopsy revealed benign fragments of endometrial glands and stroma with focal extramedullary hematopoiesis in the form of erythroid and myeloid precursors as well as megakaryocytes. The bone marrow biopsy was normal and examination of the peripheral blood revealed no abnormalities. The reticulin stain on the core biopsy revealed no myelofibrosis. Iron stains revealed no ring sideroblasts. Cytogenetic analysis revealed no observable clonal chromosomal abnormalities. Case 2 is a 42-year-old African American female with abnormal uterine bleeding. Her medical history was significant for end-stage renal disease secondary to systemic lupus erythematosus, status post failed kidney transplant. She also had hyperparathyroidism and was status post parathyroidectomy. Pelvic exam revealed a 16-week size uterus and a fibroid protruding through the cervical os. Excisional biopsy revealed a chronically inflamed benign endometrial polyp and focal extramedullary hematopoiesis composed of erythroid precursors only. Her peripheral blood revealed anemia with hemoglobin level of 8.6 g/dL. No organomegaly was found on physical exam. No follow up bone marrow biopsy was performed. Some investigators have reported extramedullary hematopoiesis in the endometrium in association with myelofibrosis, chronic myeloproliferative disorders and hematologic malignancies. However, others have found that extramedullary hematopoiesis is only rarely associated with serious underlying hematologic conditions and therefore may not warrant extensive hematologic workup. The findings from our cases support the latter conclusion.