Kapasi H, Robertson S, Futter N
Department of Pathology, University of Ottawa Faculty of Medicine, Ottawa General Hospital, Ontario, Canada.
Acta Cytol. 1998 Nov-Dec;42(6):1419-23. doi: 10.1159/000332178.
Malacoplakia is a rare chronic inflammatory disease first described by von Hansemann in 1901. L. Michaelis and M. Gutmann published the first report in 1902, describing the characteristic round intracellular and extracellular inclusions, or Michaelis-Gutmann bodies. Renal malacoplakia is a form of chronic tubulointerstitial nephritis the clinical and radiologic findings of which are often suggestive of a neoplasm. Renal malacoplakia may be related to megalocytic interstitial nephritis and xanthogranulomatous pyelonephritis.
A 67-year-old male presented with acute left loin pain suggestive of uretery colic. The past medical history was unremarkable and physical examination within normal limits. Renal ultrasound and computed tomography showed a 3.5-cm, cystic mass with a thickened, irregular wall located centrally within the left renal sinus. The size of the left kidney was 11.5 cm. A renal arteriogram provided no evidence of a vascular mass of any type. Fine needle aspiration (FNA) revealed many large, foamy, granular macrophages with large, eccentric nuclei and prominent nucleoli containing round inclusions that exhibited a laminated appearance, consistent with the structure of Michaelis-Gutmann bodies. Many were also present extracellularly.
To our knowledge this is the first case of renal malacoplakia diagnosed by fine needle aspiration. This case demonstrates the value of FNA in determining the nature of a radiologically nonspecific lesion. It highlights the value of FNA as a substitute for or preliminary method before more invasive procedures in the diagnosis of a treatable disease entity.
软斑病是一种罕见的慢性炎症性疾病，于1901年由冯·汉泽曼首次描述。L. 米夏埃利斯和M. 古特曼于1902年发表了首份报告，描述了特征性的圆形细胞内和细胞外包涵体，即米夏埃利斯-古特曼小体。肾软斑病是慢性肾小管间质性肾炎的一种形式，其临床和放射学表现常提示肿瘤。肾软斑病可能与巨细胞间质性肾炎和黄色肉芽肿性肾盂肾炎有关。
一名67岁男性因提示输尿管绞痛的急性左腰疼痛就诊。既往病史无异常，体格检查正常。肾脏超声和计算机断层扫描显示左肾窦中央有一个3.5厘米的囊性肿块，壁增厚且不规则。左肾大小为11.5厘米。肾动脉造影未发现任何类型的血管性肿块。细针穿刺抽吸（FNA）显示许多大的、泡沫状、颗粒状巨噬细胞，有大的、偏心的细胞核和突出的核仁，含有呈层状外观的圆形包涵体，与米夏埃利斯-古特曼小体的结构一致。许多包涵体也存在于细胞外。
据我们所知，这是首例通过细针穿刺抽吸诊断的肾软斑病病例。该病例证明了FNA在确定放射学上非特异性病变性质方面的价值。它突出了FNA作为一种替代方法或在更具侵入性的程序之前用于诊断可治疗疾病实体的初步方法的价值。
