Prominent increase of Pappenheimer body-containing erythrocytes in a patient with hypoplastic spleen (IJHM-D-18-00279R2)

Excerpt

A 70-year-old male presented with macrocytic anemia during follow-up for hypertension and chronic kidney disease, and was referred to the hospital. Laboratory findings at that time were as follows: hemoglobin, 8.4 g/dL; mean corpuscular volume 110.6 fL; platelets, 383 × 10⁹/L; white blood cells, 6.3 × 10⁹/L, with normal differentials; estimate glomerular filtration rate, 58.2 mL/min (normal range > 90); erythropoietin, 72.2 mIU/mL (4.2–23.7); vitamin B₁₂ 196 pg/mL (233–914); folate 1.6 ng/mL (3.6–12.9). Of note, more than half of his peripheral blood erythrocytes contained Pappenheimer bodies (Fig. 1). Howell–Jolly bodies were also noted in 2% of his erythrocytes. The bone marrow was normocellular with a high M/E ratio, and Pappenheimer bodies were also frequently found. However, myelodysplastic or megaloblastic changes were not apparent, with 3% ring sideroblasts. Chromosomal analysis of his bone marrow revealed the normal male karyotype. He had no history of splenectomy, lead poisoning, alcohol excess, isoniazid therapy, porphyria or hemoglobinopathies known to cause Pappenheimer bodies [1]. Urine coproporphyrin was also not elevated. On the other hand, computed tomography of his abdomen revealed that his spleen was markedly small (< 5 cm in maximal diameter) (Fig. 2). It was unclear whether his spleen was congenitally hypoplastic, but he had never experienced severe complications such as pneumococcal infection. …