Hemophagocytic lymphohistiocytosis (HLH) constitutes a life-threatening inflammatory syndrome. Postmortem histological findings of bone marrow (BM) from COVID-19 patients showed histiocytosis and hemophagocytosis and supported the hypothesis that secondary HLH (sHLH) may be triggered by SARS-CoV-2 infection. However, there are a limited number of sHLH cases in which trephine has been performed in living post-COVID-19 patients. Here we present a recent case and a mini-review of sHLH diagnosed by trephine biopsy in living patients after COVID-19. An 81-year-old man with a past medical history of hypertension, diabetes, ischemic stroke, was referred to the hospital to evaluate leukocytosis, pyuria, and elevation of inflammatory markers four weeks after recovering from COVID-19. Computed tomography of the abdomen did not reveal focal signs of infection or hepatosplenomegaly. The patient received intravenous meropenem and two packed red blood cell units. Leukocytes and C-reactive protein were gradually decreased. A BM biopsy was performed and the patient was discharged on cefixime. BM smear revealed severe anemia, lymphopenia, and dysplastic morphologic findings of erythroblasts, neutrophils, and megakaryocytes. Trephine biopsy revealed hypercellular marrow dyserythropoiesis, plasmacytosis, lymphocytosis, histiocytosis, hemophagocytosis, and the absence of granulomas or carcinoma. Immunohistochemistry documented a mixed population of T lymphocytes (CD3+) and B lymphocytes (CD20+). Strong positivity for CD68 confirmed histiocytosis. CD138 κ, λ staining proved polyclonal plasmacytosis. Perl’s staining showed excess hemosiderin deposits. Based on our findings, we document sHLH in trephine BM biopsy of a living post-COVID-19 patient and persistent leukocytosis, underscoring the diagnostic value of trephine biopsy in preventing life-threatening conditions such as COVID-19.

噬血细胞性淋巴组织细胞增多症（HLH）是一种危及生命的炎症综合征。 COVID-19 患者的骨髓 (BM) 死后组织学结果显示组织细胞增多和噬血细胞增多，并支持继发性 HLH (sHLH) 可能由 SARS-CoV-2 感染引发的假设。然而，对在世的 COVID-19 后患者进行环钻手术的 sHLH 病例数量有限。在这里，我们介绍一个最近的病例，并对在生的 COVID-19 患者中通过环锯活检诊断出 sHLH 进行小型回顾。一名 81 岁男性，既往有高血压、糖尿病、缺血性中风病史，在 COVID-19 康复 4 周后被转诊至医院评估白细胞增多、脓尿和炎症标志物升高。腹部计算机断层扫描未显示局部感染迹象或肝脾肿大。患者接受静脉注射美罗培南和两个浓缩红细胞单位。白细胞和C反应蛋白逐渐下降。进行了骨髓活检，患者出院后服用头孢克肟。 BM涂片显示严重贫血、淋巴细胞减少以及成红细胞、中性粒细胞和巨核细胞发育不良的形态学表现。环钻活检显示骨髓红细胞生成增多、浆细胞增多、淋巴细胞增多、组织细胞增多、噬血细胞增多，并且没有肉芽肿或癌。免疫组织化学记录了 T 淋巴细胞 (CD3+) 和 B 淋巴细胞 (CD20+) 的混合群体。 CD68 强阳性证实了组织细胞增多症。 CD138 κ、λ染色证明多克隆浆细胞增多症。 Perl染色显示过量的含铁血黄素沉积。 根据我们的研究结果，我们记录了一名活体 COVID-19 后患者的环钻骨髓活检中的 sHLH 和持续性白细胞增多，强调了环钻活检在预防危及生命的疾病（如 COVID-19）方面的诊断价值。