Asou Mea, Asakawa Tomohiko, Araki Makoto, Ehara Takashi, Hishima Tsunekazu, Sakamaki Hisashi
Department of Internal Medicine, Suwa Central Hospital, Chino, Japan.
Graduate School of Health Sciences, Matsumoto University, Matsumoto, Japan.
Case Rep Nephrol Dial. 2021 Jan 25;11(1):1-9. doi: 10.1159/000510142. eCollection 2021 Jan-Apr.
Extramedullary hematopoiesis is widely known to occur in patients with primary myelofibrosis (PMF). Autopsy studies on individuals with PMF revealed that extramedullary hematopoiesis occurred in the kidneys in 35% of the cases, but there is little awareness regarding such lesions. A 63-year-old man was diagnosed with PMF based on a detailed examination of persistent high white blood cells. An examination of the patient's medical records revealed an increased white blood cell count, deterioration of kidney function, and urinary protein excretion developed simultaneously. Thus, a kidney biopsy was performed. Advanced lymphocyte invasion was recognized in the interstitial tissue, and the tubular structure was highly disrupted. Based on these findings, he was diagnosed with interstitial nephritis. However, because of the large number of cells with nuclear atypia in the stroma, additional immunohistochemical staining was also performed, such as glycophorin A, naphthol AS-D, myeloperoxidase, and CD42b. As a result, invasion of three lineages of immature cells, erythroblasts, megakaryocytes, and granulocytes, was identified. Renal dysfunction resulting from interstitial cellular infiltration due to extramedullary hematopoiesis was therefore diagnosed. Treatment with ruxolitinib was initiated after a renal biopsy and the rate of decline in renal function was slightly reduced. Although, in myeloproliferative disorders, proliferative glomerular lesions are widely considered to be renal disorders, there is little awareness regarding interstitial lesions. Extramedullary hematopoiesis of the kidney in PMF is not uncommon, but 40% of cases are reportedly misdiagnosed as interstitial nephritis. Because extramedullary hematopoiesis can be controlled by ruxolitinib, early detection is important.
众所周知，原发性骨髓纤维化（PMF）患者会发生髓外造血。对PMF患者的尸检研究表明，35%的病例中髓外造血发生在肾脏，但人们对这类病变了解甚少。一名63岁男性经详细检查发现持续高白细胞后被诊断为PMF。对该患者病历的检查发现，白细胞计数升高、肾功能恶化和尿蛋白排泄同时出现。因此，进行了肾脏活检。在间质组织中发现了大量淋巴细胞浸润，肾小管结构严重破坏。基于这些发现，他被诊断为间质性肾炎。然而，由于基质中存在大量核异型细胞，还进行了其他免疫组化染色，如血型糖蛋白A、萘酚AS-D、髓过氧化物酶和CD42b。结果，鉴定出未成熟细胞的三个谱系，即成红细胞、巨核细胞和粒细胞的浸润。因此，诊断为髓外造血引起的间质细胞浸润导致的肾功能障碍。肾脏活检后开始使用芦可替尼治疗，肾功能下降速率略有降低。虽然在骨髓增殖性疾病中，增殖性肾小球病变被广泛认为是肾脏疾病，但人们对间质病变了解甚少。PMF患者肾脏的髓外造血并不罕见，但据报道40%的病例被误诊为间质性肾炎。由于髓外造血可由芦可替尼控制，早期检测很重要。
