Bain E Eugene, Meehan Shane A, Hale Elizabeth K
J Drugs Dermatol. 2014 May;13(5):598-600.
Necrobiotic xanthogranuloma (NXG) is an uncommon granulomatous disorder of unknown pathogenesis that often presents with yellowish plaques in a periorbital distribution. While a majority of cases are associated with an underlying paraproteinemia of the IgG kappa type, a much smaller number are found to be associated with an underlying multiple myeloma. We present a case of a 78-year-old male with an isolated lesion of NXG on his right upper extremity. Following his diagnosis of NXG, further investigation for underlying systemic disorders with serum immunofixation revealed a monoclonal IgG kappa immunoglobulin with an M-spike of 1.2 g/dL. A PET-CT demonstrated bone destruction in the left proximal fifth rib, left scapula, the anterior lumbar I (L1) vertebrae, the left lumbar III (L3) vertebrae posterior elements and possibly left sacrum. A bone marrow biopsy revealed 18 % plasma cells. With these findings he was diagnosed with stage I multiple myeloma. Though clinically unimpressive and atypical in location for NXG, early biopsy and diagnosis of this solitary lesion led to the discovery of his hematopoietic disorder.
坏死性黄色肉芽肿（NXG）是一种发病机制不明的罕见肉芽肿性疾病，常表现为眶周分布的淡黄色斑块。虽然大多数病例与IgG κ型潜在副蛋白血症相关，但发现与之相关的潜在多发性骨髓瘤的病例要少得多。我们报告一例78岁男性，其右上肢有孤立性NXG病变。在诊断为NXG后，通过血清免疫固定对潜在的全身性疾病进行进一步检查，发现单克隆IgG κ免疫球蛋白，M峰为1.2 g/dL。PET-CT显示左近端第五肋骨、左肩胛骨、第一腰椎（L1）椎体前部、左第三腰椎（L3）椎体后部以及可能的左骶骨有骨质破坏。骨髓活检显示浆细胞占18%。根据这些发现，他被诊断为I期多发性骨髓瘤。尽管该病例临床表现不明显且病变部位对于NXG来说不典型，但对这个孤立病变进行早期活检和诊断导致发现了他的造血系统疾病。
