LAUSR

A 55-year-old man presented to our hospital because of leukocytosis in October 2020. He had a history of hypertension and suffered from recurrent pancreatitis since the previous year. Laboratory findings on admission were as follows: white blood cell count, 43.28 × 109/L; hemoglobin level, 12.6 g/dL; and platelet count, 643 × 109/L. Bone marrow aspiration revealed hypercellular marrow with 2.2% myeloblasts. The BCR-ABL fusion gene was detected using real-time quantitative reversetranscription polymerase chain reaction. The Philadelphia chromosome (Ph), a reciprocal translocation of chromosomes 9 and 22, was observed at 96.8% using fluorescent in situ hybridization. The karyotype was 46,XY,t(9;22)(q34;q11.2). He was diagnosed with chronic myelogenous leukemia (CML) and treated with dasatinib (100 mg qd). Abdominal computed tomography (CT) upon admission showed a 3.0-cm-sized welldefined, enhancing mass in the right adrenal gland. The plasma adrenocorticotropic hormone level was < 1.2 pg/mL (normal, 6–30). The plasma cortisol, aldosterone, epinephrine, norepinephrine, renin, and 24-h urinary metanephrine concentrations were within normal ranges. A nonfunctioning adenoma was considered. A major molecular response was achieved after 5 months of dasatinib therapy. A complete cytogenetic response (CCR) in the bone marrow was confirmed in July 2021. Follow-up kidney CT in April 2021 showed a well-defined adenoma without change in size. However, a distinct 1.0-cm nonenhancing mass with a fatty component appeared inside the adenoma. We reviewed the previous CT findings and found a small indistinct hypodense lesion within the adenoma. Adrenalectomy was performed; a well-defined heterogeneous goldenyellow to dark brown solid mass measuring 3.2 × 2.8 × 1.2 cm was isolated. A hemorrhagic mass measuring 1.5 × 1.0 cm was observed centrally within the tumor. Microscopically, the tumor was arranged in a thick trabecular and alveolar growth pattern with epithelioid cells with abundant eosinophilic and clear cytoplasm and round uniform nuclei. There was no tumor necrosis, solid sheet formation, venous invasion, or capsule invasion. Mitosis was absent. The mass was diagnosed as an adrenal cortical adenoma (ACA). The hemorrhagic mass showed a relatively well-defined mass but was unencapsulated and consisted of mature adipose tissue and three lineages of hematopoietic cells without atypical morphology or blasts. Sheets or clusters of hematopoietic cells were scattered throughout the ACA with or without fat components (Fig. 1). Adrenal ML, with unclear pathogenesis, has been reported isolated and in association with other adrenal pathologic diseases at a frequency of 5–15% [1]. Altered mesenchymal stem cell functioning, hormonal effects, infection, necrosis, and stress induce ML formation [1, 2]. Extramedullary hematopoiesis (EMH) is the proliferation of all three cell lineages in extramedullary sites occurring as a physiological compensatory phenomenon in response to altered hematopoiesis due to inadequate bone marrow function, such as anemia and myelodysplastic syndrome [3, 4]. The liver and spleen are common sites for EMH; it is rarely found in the adrenal gland. Adrenal EMH has usually been reported in patients with beta-thalassemia or hereditary spherocytosis. EMH is an infrequent complication for patients with CML and occurs in the later stage of CML, associated with myelofibrosis [5]. Pathologically, both ML and EMH present as masses, without definite pathological difference. ML and EMH can be distinguished by the presence of a history of hematopoietic disorders; fat is not an obligatory component [2, 4]. Although there was no change in the ACA size, the ML lesion had increased in size and appeared as a definite mass with bleeding in 5 months. What was the initial diagnosis of the lesion? * Mi-Jin Gu [email protected]