Department of Pathology, Kurume University School of Medicine, Kurume, Japan; Department of Surgical Pathology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
Department of Pathology, Kurume University School of Medicine, Kurume, Japan.
Pathology. 2022 Jun;54(4):442-448. doi: 10.1016/j.pathol.2021.08.015. Epub 2021 Nov 28.
Myeloid sarcoma (MS) is defined as a tumour mass consisting of myeloid blasts that occurs at an anatomical site other than bone marrow. MS with megakaryocytic differentiation (MSmgk) is extremely rare and its clinicopathological features have not been well described. We reviewed 11 cases in 11 patients of extramedullary mass-forming malignant tumours composed of immature non-lymphoid haematopoietic cells expressing CD41 with or without concurrent bone marrow lesions. The patients consisted of seven men and four women (1.75:1 male-to-female ratio). The mean and median ages at diagnosis were 50 and 62 years, respectively, ranging from 2 to 78 years. Extramedullary mass lesions were solitary in three cases (27%) and multiple in eight cases (73%). Tumour locations were lymph nodes (6 cases), subcutaneous tissue (3 cases), intramuscular (1 case), and bone (1 case). Seven of the 11 patients (64%) had a history of myelodysplastic syndrome (MDS) or myeloproliferative neoplasm (MPN). Three patients (27%) developed MS during remissions of acute myelogenous leukaemia, and one patient had a recurrence of MS at other sites. Follow-up data were available for four cases. Tumour cells were positive for CD41, CD33, CD34, MPO, and CD68 in 11 (100%), three (27%), seven (64%), four (36%), and seven (64%) cases, respectively. Cytogenetic analysis was successfully performed in two cases. Complex but inconsistent abnormalities were evident. When compared with cases of MS without megakaryocytic differentiation, the survival of MSmgk was significantly shorter (p=0.0033). Compared to MS without megakaryocytic differentiation, MSmgk is more likely to follow MDS/MPN, to involve multiple sites, and to be associated with poorer outcomes. More detailed studies, including genomic or gene expression analyses, could confirm the characteristics of MSmgk.
骨髓肉瘤（MS）定义为发生于骨髓以外解剖部位的、由髓系原始细胞构成的肿瘤团块。伴巨核细胞分化的 MS（MSmgk）极其罕见，其临床病理特征尚未得到充分描述。我们复习了 11 例 11 例患者的病例资料，这些患者均存在骨髓外肿块形成的恶性肿瘤，由表达 CD41 的不成熟非淋巴造血细胞组成，伴有或不伴有骨髓病变。患者中男 7 例，女 4 例（男女比例为 1.75：1）。诊断时的平均和中位年龄分别为 50 岁和 62 岁，年龄范围为 2-78 岁。3 例（27%）患者的髓外肿块为单发，8 例（73%）患者为多发。肿瘤部位分别为淋巴结（6 例）、皮下组织（3 例）、肌肉内（1 例）和骨（1 例）。11 例患者中有 7 例（64%）有骨髓增生异常综合征（MDS）或骨髓增殖性肿瘤（MPN）病史。3 例（27%）患者在急性髓系白血病缓解期间发生 MS，1 例患者在其他部位复发 MS。4 例患者的随访资料可用。11 例（100%）、3 例（27%）、7 例（64%）、4 例（36%）和 7 例（64%）患者的肿瘤细胞分别表达 CD41、CD33、CD34、MPO 和 CD68。2 例患者成功进行了细胞遗传学分析，结果显示存在复杂但不一致的异常。与无巨核细胞分化的 MS 相比，MSmgk 的生存时间显著缩短（p=0.0033）。与无巨核细胞分化的 MS 相比，MSmgk 更易继发于 MDS/MPN，更易累及多个部位，且预后更差。更详细的研究，包括基因组或基因表达分析，可能会进一步证实 MSmgk 的特征。
