Department of Pathology, PSG Institute of Medical Sciences and Research, Coimbatore, India.
Department of Pathology, PSG Institute of Medical Sciences and Research, Coimbatore, India.
Pathology. 2024 Apr;56(3):382-390. doi: 10.1016/j.pathol.2023.10.017. Epub 2024 Jan 6.
Kikuchi-Fujimoto disease (KFD) is a benign self-limiting condition primarily affecting young females. It usually presents with fever and cervical lymphadenopathy of unknown aetiology with a preponderance of the Asian population. Histopathology is critical in making an accurate diagnosis. While the typical microscopic features include paracortical necrosis with debris, histiocytosis with immunoblasts, and absent neutrophils, rarely, KFD can show atypical features like marked immunoblastic proliferation mimicking lymphoma, demonstrate vasculitis mimicking lupus erythematosus, etc. The diagnosis is extremely challenging if such features occur in cases with generalised lymphadenopathy, which is infrequent in KFD. The study aims to describe the morphological, clinical, and immunohistochemical features of KFD and determine the frequency of the atypical features. We also analysed the subtle histological and immunohistochemical features that aid in the diagnosis of atypical cases. Cases reported as KFD over a period of 6 years were retrieved from the archives of histopathology. The morphological features were categorised as typical and atypical. In the atypical cases, the features that aided in the correct diagnosis of KFD were analysed. Out of the 42 cases evaluated, 23.9% (n=10) had generalised lymphadenopathy; 57.2% (n=24) were women with a median age of 25 years. Leukopenia was observed in 42% (n=13) of patients. Typical features were present in 76.2% (n=32) cases and 23.8% (n=10) presented with atypical features. Eight cases were antinuclear antibody-positive. Atypical features included five (50%) cases with vasculitis and panniculitis, and three (30%) cases with large, atypical cells for which immunohistochemistry (IHC) was performed. In two of these cases, the patent sinuses, absence of neutrophils, and IHC with CD68 aided the diagnosis. There is an overlap of clinical and histopathological features between KFD and malignant lymphomas and systemic lupus erythematosus. Given the fact that the atypical features (23.8%) are not rare occurrences in KFD, correlations with clinical findings and ancillary studies are essential to avoid misdiagnosis and inadvertent therapy.
菊池-藤本病（KFD）是一种良性自限性疾病，主要影响年轻女性。它通常表现为发热和病因不明的颈淋巴结病，亚洲人群居多。组织病理学在做出准确诊断方面至关重要。虽然典型的显微镜特征包括皮质旁坏死伴碎屑、组织细胞增生伴免疫母细胞和无中性粒细胞，但在极少数情况下，KFD 可表现出不典型特征，如模仿淋巴瘤的显著免疫母细胞增生、模仿红斑狼疮的血管炎等。如果在 KFD 中出现这种特征，且淋巴结广泛受累，诊断极具挑战性，而这种情况并不常见。本研究旨在描述 KFD 的形态学、临床和免疫组织化学特征，并确定不典型特征的频率。我们还分析了有助于诊断不典型病例的细微组织学和免疫组织化学特征。从组织病理学档案中检索了过去 6 年报告的 KFD 病例。将形态学特征分为典型和不典型。在不典型病例中，分析了有助于正确诊断 KFD 的特征。在评估的 42 例病例中，23.9%（n=10）有广泛的淋巴结病；57.2%（n=24）为女性，中位年龄为 25 岁。42%（n=13）的患者出现白细胞减少。76.2%（n=32）的病例存在典型特征，23.8%（n=10）的病例存在不典型特征。8 例抗核抗体阳性。不典型特征包括 5 例（50%）血管炎和脂膜炎，3 例（30%）大而不典型的细胞，对其进行了免疫组织化学（IHC）检查。在其中 2 例中，窦道通畅、无中性粒细胞和 CD68 的 IHC 有助于诊断。KFD 与恶性淋巴瘤和系统性红斑狼疮的临床和组织病理学特征存在重叠。鉴于 KFD 中不典型特征（23.8%）并不罕见，与临床发现和辅助研究的相关性对于避免误诊和意外治疗至关重要。
