Ozdemirli M, Fanburg-Smith J C, Hartmann D P, Shad A T, Lage J M, Magrath I T, Azumi N, Harris N L, Cossman J, Jaffe E S
Department of Pathology, Georgetown University Medical Center, Washington, DC 20007, USA.
Am J Surg Pathol. 1998 Jul;22(7):795-804. doi: 10.1097/00000478-199807000-00002.
Precursor B-lymphoblastic lymphoma (B-LBL) may present as a solitary bone tumor. Fewer than 10 cases with a proven precursor B-cell phenotype have been reported in the English literature. In this report, we describe four cases of B-lymphoblastic lymphoma presenting as a localized intraosseous mass, which clinically and histologically mimicked Ewing's sarcoma. Three tumors occurred in the tibia and one in the humerus. In all four cases, the initial diagnosis was either "Ewing's sarcoma" or "consistent with Ewing's sarcoma." All four patients were female. Three were children and one was an adult; mean age was 12.5 years (range, 4 to 31 years). All had extremity pain without significant constitutional symptoms. In three cases, the tumors were osteolytic on radiographic evaluation, and in one case, osteosclerotic. Immunohistochemical stains on paraffin-embedded tissue showed that the neoplastic cells expressed terminal deoxynucleotidyl transferase, CD43, vimentin, and CD99 (MIC2 gene product) in all cases. Three cases were negative for CD45. CD79a was positive in all four cases studied; however, CD20 (L26) was positive in only two of four cases. CD3 was negative in all cases. Two cases showed focal granular cytoplasmic staining for keratin. Two cases analyzed by polymerase chain reaction (PCR) revealed clonal rearrangement of the immunoglobulin heavy chain (IgH) gene. Follow-up revealed that the three pediatric patients, who received a high-dose multiagent chemotherapy regime for LBL, are disease free at follow-up intervals of more than 1, 11, and 12 years, respectively. The adult patient died two years after diagnosis with disseminated disease. Although rare, B-lymphoblastic lymphoma should be considered in the differential diagnosis of small round cell tumors of bone. A diagnosis of Ewing's sarcoma should be made only after complete immunophenotyping and, if necessary, molecular diagnostic tests to exclude lymphoblastic lymphoma. A limited panel of antibodies can lead to an erroneous diagnosis; B-lymphoblastic lymphoma may be negative for CD45 and CD20 but positive for CD99 and even for keratin, mimicking Ewing's sarcoma. Correct diagnosis is extremely important because LBL usually is curable in the pediatric age group with appropriate therapy.
前体B淋巴细胞淋巴瘤（B-LBL）可能表现为孤立性骨肿瘤。英文文献中报道的经证实具有前体B细胞表型的病例少于10例。在本报告中，我们描述了4例表现为局限性骨内肿块的B淋巴细胞淋巴瘤，其临床和组织学表现酷似尤因肉瘤。3例肿瘤发生于胫骨，1例发生于肱骨。在所有4例中，最初诊断均为“尤因肉瘤”或“符合尤因肉瘤”。所有4例患者均为女性。3例为儿童，1例为成人；平均年龄为12.5岁（范围4至31岁）。所有患者均有肢体疼痛，无明显全身症状。3例经影像学评估肿瘤呈溶骨性，1例呈骨硬化性。石蜡包埋组织的免疫组化染色显示，所有病例肿瘤细胞均表达末端脱氧核苷酸转移酶、CD43、波形蛋白和CD99（MIC2基因产物）。3例CD45阴性。所有4例研究病例中CD79a均为阳性；然而，4例中仅2例CD20（L26）阳性。所有病例CD3均为阴性。2例显示角蛋白局灶性颗粒状胞质染色。2例经聚合酶链反应（PCR）分析显示免疫球蛋白重链（IgH）基因克隆性重排。随访发现，3例接受针对LBL的大剂量多药化疗方案的儿科患者，分别在随访1年、11年和12年以上时无疾病。成年患者诊断为播散性疾病后两年死亡。尽管罕见，但在骨小圆细胞瘤的鉴别诊断中应考虑B淋巴细胞淋巴瘤。只有在完成免疫表型分析并在必要时进行分子诊断检测以排除淋巴细胞淋巴瘤后，才能做出尤因肉瘤的诊断。一组有限的抗体可能导致错误诊断；B淋巴细胞淋巴瘤可能CD45和CD20阴性，但CD99甚至角蛋白阳性，酷似尤因肉瘤。正确诊断极为重要，因为LBL在儿童年龄组中通过适当治疗通常可治愈。
