Oschlies Ilske, Richter Julia, Alfert Amelie, Chahud Fernando, Mueller Stephanie, Simonitsch-Klupp Ingrid, von Mersi Hannah, Attarbaschi Andishe, Koch Karoline, Schaefers Christoph, Brüggemann Monika, Bozzetti Cecilia, Woessmann Wilhelm, Burkhardt Birgit, Klapper Wolfram
Hematopathology Section and Lymph Node Registry, Department of Pathology, University Hospital Schleswig-Holstein, Campus Kiel, Kiel, Germany.
Department of Pediatric Hematology and Oncology and NHL-BFM Study Center, University Hospital Muenster, Muenster, Germany.
Blood Adv. 2025 Aug 12;9(15):3909-3918. doi: 10.1182/bloodadvances.2025016596.
Extramedullary plasmacytomas (EMPs) are exceedingly rare in children and adolescents. We describe clinical, pathological, and molecular features of 13 patients with EMP in this age group (8 males and 5 females; age 3-18 years). EMPs presented as localized disease involving the Waldeyer's ring (n = 9), larynx (n = 2), ocular adnexa (n = 1), or epipharynx and conjunctiva simultaneously (n = 1). One patient with EMP of the tonsils had a concurrent Epstein-Barr virus infection. Twelve of 13 patients with follow-up information reached sustained complete remissions after surgical resection (median follow-up, 38 months). However, local relapses were observed in 3 patients. Irradiation was applied in only 1 patient with laryngeal involvement. Histologically, sheets of mature plasma cells with light chain restriction, low proliferation, and predominant expression of immunoglobulin A (11/13 [92%]) were observed. Epstein-Barr virus, CD56, and cyclin D1 were not detected in the plasma cells. Amyloidosis confined to the lesion was observed in 1 case. Clonal, mostly productive immunoglobulin gene rearrangements with somatic hypermutation (3.3%-5.7%) were detectable in all informative cases. Fluorescence in situ hybridization revealed absence of chromosomal abnormalities associated with plasma cell neoplasia (eg, breaks in IGH, MAF, FGFR3, and copy number alterations of 1p32, 1q21, RB1, and TP53). Targeted next-generation sequencing did not reveal any somatic alterations predicted as pathogenic. We conclude that EMP in children and adolescents is a plasma cell neoplasia with low malignant potential lacking systemic dissemination, differing clinically and molecularly from adult plasma cell myeloma.
髓外浆细胞瘤（EMPs）在儿童和青少年中极为罕见。我们描述了该年龄组13例EMP患者的临床、病理和分子特征（8例男性和5例女性；年龄3至18岁）。EMPs表现为局限性疾病，累及瓦尔代尔环（n = 9）、喉（n = 2）、眼附属器（n = 1）或同时累及咽上部和结膜（n = 1）。1例扁桃体EMP患者同时感染了爱泼斯坦-巴尔病毒。13例有随访信息的患者中，12例在手术切除后达到持续完全缓解（中位随访时间38个月）。然而，3例患者出现局部复发。仅1例喉部受累患者接受了放疗。组织学上，观察到成片的成熟浆细胞，有轻链限制、低增殖以及免疫球蛋白A的主要表达（11/13 [92%]）。浆细胞中未检测到爱泼斯坦-巴尔病毒、CD56和细胞周期蛋白D1。1例观察到局限于病变部位的淀粉样变性。在所有可提供信息的病例中均检测到克隆性的、大多为有功能的免疫球蛋白基因重排以及体细胞超突变（3.3% - 5.7%）。荧光原位杂交显示不存在与浆细胞肿瘤相关的染色体异常（例如IGH、MAF、FGFR3断裂以及lp32、1q21、RB1和TP53的拷贝数改变）。靶向二代测序未发现任何预测为致病性的体细胞改变。我们得出结论，儿童和青少年的EMP是一种恶性潜能低且缺乏全身播散的浆细胞肿瘤，在临床和分子方面与成人浆细胞骨髓瘤不同。
