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 患者骨髓 (BM) 的尸检组织学结果显示组织细胞增多症和噬血细胞增多症，并支持继发性 HLH (sHLH) 可能由 SARS-CoV-2 感染引发的假设。然而，在 COVID-19 后存活患者中进行环钻的 sHLH 病例数量有限。在这里，我们介绍了 COVID-19 后活体患者通过环钻活检诊断的 sHLH 的最新病例和小型回顾。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 周后被转诊到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发现感染或肝脾肿大的局灶体征。患者接受了静脉注射美罗培南和两个浓缩红细胞单位。白细胞和C反应蛋白逐渐减少。进行了 BM 活检，患者使用头孢克肟出院。BM 涂片显示严重贫血、淋巴细胞减少和成红细胞、中性粒细胞和巨核细胞发育异常的形态学发现。环钻活检显示高细胞骨髓红细胞生成异常、浆细胞增多症、淋巴细胞增多症、组织细胞增多症、噬血细胞增多症，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 的强阳性证实了组织细胞增多症。CD138 κ、λ 染色证实多克隆浆细胞增多症。Perl 染色显示含铁血黄素沉积过多。根据我们的研究结果，我们记录了 COVID-19 后活体患者的环钻 BM 活检和持续性白细胞增多症中的 sHLH，强调了环钻活检在预防 COVID-19 等危及生命的疾病方面的诊断价值。