Manzalji Kamar, Humaida Sara, Ramadan Abd Alrhem, Mudawi Aiman, Ganwo Ibrahim, Moghamis Isam Sami
Primary Health Care Center, Family Medicine, Doha, Qatar.
Hamad Medical Corporation, Pediatric Medicine, Doha, Qatar.
Int J Surg Case Rep. 2024 Aug;121:109956. doi: 10.1016/j.ijscr.2024.109956. Epub 2024 Jun 27.
Myeloid sarcoma (MS) is a rare extramedullary tumor composed of malignant myeloid cells that most commonly arise in patients previously diagnosed with myeloproliferative disease. However, they can still occur in isolation and without bone marrow disease.
An 8-year-old girl who had a history of acute myeloid leukemia and was off treatment for four years presented to the clinic with a history of on and off left knee swelling and pain without any direct trauma to the knee over the last two years. Knee Magnetic resonance imaging (MRI) showed diffused joint effusion with proximal tibia focal edema. A diagnosis of juvenile rheumatoid arthritis was suspected, and the patient was started on treatment, but the problem did not resolve. Eventually, the patient underwent a repeat MRI and showed increased joint effusion with an increase in the focal edema. An open bone biopsy of the lesion was taken, and the histopathology showed sheets of primitive mononuclear cells positive for CD33 and CD117 and negative for CD34, myeloperoxidase, CD10, CD20, and CD68, indicating myeloid sarcoma.
Histological examination and immunohistochemistry are the most important in diagnosing myeloid sarcoma. Previously, before the introduction of chemotherapy and stem cell transplant, such cases of proximal tibia MS were treated with surgical resection of the bone. However, chemotherapy with the possibility of an allogeneic hematopoietic stem cell transplant (alloHSCT) has changed the view of survival in such cases.
Isolated proximal tibia myeloid sarcoma is a rare occurrence that can be misdiagnosed and lead to delayed treatment. Bone biopsy, Immunohistochemistry, and cytogenetic studies play a critical role in differentiating MS from other types of tumors.
髓系肉瘤（MS）是一种罕见的髓外肿瘤，由恶性髓系细胞组成，最常见于先前被诊断患有骨髓增殖性疾病的患者。然而，它们也可能孤立出现且无骨髓疾病。
一名8岁女孩，有急性髓系白血病病史，已停止治疗四年，因过去两年左膝反复肿胀和疼痛前来就诊，膝盖无任何直接外伤史。膝关节磁共振成像（MRI）显示弥漫性关节积液，胫骨近端局灶性水肿。怀疑诊断为幼年类风湿关节炎，患者开始接受治疗，但问题未得到解决。最终，患者再次进行MRI检查，显示关节积液增加，局灶性水肿加重。对病变进行了开放性骨活检，组织病理学显示成片的原始单核细胞CD33和CD117呈阳性，CD34、髓过氧化物酶、CD10、CD20和CD68呈阴性，提示为髓系肉瘤。
组织学检查和免疫组织化学在诊断髓系肉瘤中最为重要。以前，在化疗和干细胞移植出现之前，此类胫骨近端MS病例采用骨手术切除治疗。然而，化疗以及异体造血干细胞移植（alloHSCT）的可能性改变了此类病例的生存观念。
孤立性胫骨近端髓系肉瘤罕见，可能被误诊并导致治疗延迟。骨活检、免疫组织化学和细胞遗传学研究在鉴别MS与其他类型肿瘤方面起着关键作用。
