Multiple Jejunal Myeloid Sarcomas Presenting with Intestinal Obstruction in a Non-leukemic Patient: A Case Report with Ultrastructural Observations
A 49-year-old man presented with recurrent central colicky abdominal pain, which had commenced 2 weeks earlier. Abdominopelvic computed tomography (CT) showed a mass-like lesion at the left upper abdominal region (). Segmental resection of the jejunum 30 cm below the Treitz ligament was performed. Intraoperatively, the obstructed portion was conglomerated and adhered to other segments of the distal small intestine. The mass-like portion demonstrated thick adhesion to the transverse colon and superior mesentery.\nThe resected segment measured 106 cm in length. The cut surface revealed two portions of circumferential stricture by two separate ulceroinfiltrating masses. The masses measured 15×10 cm and 12×10 cm each. The masses were separated from each other by 21 cm. Grossly, the masses showed transmural involvement and had invaded through the proper muscle layer of the adhered segment of the jejunum. The cut surface had a brown-colored homogeneous and fish-fleshy appearance (). The mucosal surfaces of the masses were coated by necrotic exudates. Histologically, each tumor was diffusely infiltrated by round small to moderately sized cells containing eosinophilic granular cytoplasm (). The tumor cells were irregularly shaped with angulated nuclei, irregular nuclear contours, and fine chromatin. Immunohistochemically, the tumor cells were cytoplasmically stained with CD68 (1:100, KP1, Lab Vision Co., Cheshire, UK) (), CD99 (prediluted, 12E7, Dako, Glostrup, Denmark) () and vimentin (prediluted, V9, Dako). The cells produced negative results for myeloperoxidase (MPO), toluidine blue, lysozyme, terminal deoxynucleotidyl transferase (TdT), nonspecific esterase, leukocyte common antigen (prediluted, Dako), CD3 (prediluted, polyclonal, Dako), CD4 (4B12, prediluted, Dako), CD15 (1:50, Carb-3, Dako), CD20 (prediluted, polyclonal, L26, Dako), CD30 (prediluted, Ber-H2, Dako), CD43 (prediluted, Dako), CD56 (1:100, 123C2, Dako), CD68 (1:50, PG-M1, Dako), CD79a (1:50, JCB117, Dako), human melanoma black-45 (prediluted, HMB-45, Dako), CD117 (prediluted, c-kit, Dako), and CD34 (prediluted, QBEnd10, Dako). To exclude the remote possibility of a gastrointestinal stromal tumor (GIST), platelet-derived growth factor receptor-alpha (PDGFRA) and c-kit mutation studies were performed using polymerase chain reaction sequencing. No PDGFRA or c-kit mutations were observed.\nUpon examination of their ultrastructure, the ovoid-shaped tumor cells possessed peripherally condensed chromatin with occasional involuted configurations (). The tumor cells were packed with abundant intracytoplasmic membrane-bound granules that measured from 200 to 300 nm in diameter. The rectangular inclusions revealed a fine lamellar substructure, and the periodicity of the filamentous striations was about 10 nm (). The peripheral blood smears failed to demonstrate any abnormal hematopoietic cells or blasts. Myeloid sarcoma was diagnosed. A bone marrow study was not performed due to the patient's request. After the operation, a chest CT showed a 7 cm heterogeneous enhancing cavitary mass within low density in the right upper lobe. At that time, two enhancing small nodules were found at the liver. After 7 months, the size of the masses of the lung and liver had enlarged slightly. The peripheral blood smears indicated that no abnormal myeloid cells or blasts remained. Biopsies were not taken from these organs. The patient experienced severe recurrent hemoptysis. His condition continued to decline and then he died. An autopsy was not performed.