Lymphangioleiomyomatosis (LAM) is a proliferation of perivascular epithelioid cells typically affecting the lung as a low-grade, destructive and progressive disease but may also be found in lymph nodes and other organs. LAM is sometimes seen as an incidental finding in lymph node dissections performed for staging of gynecologic tumors. To our knowledge, no study has investigated the clinical significance of incidental nodal LAM in relation to subsequent development of pulmonary LAM. We identified 19 patients from our institution with LAM in lymph nodes. Follow-up was available for 100% of patients and ranged from 3 to 123 months (mean 33.8 mo). All were women, ranging in age from 35 to 71 years (mean 56.3 y). None had a history of tuberous sclerosis, renal angiomyolipoma, or pulmonary LAM. LAM involvement spanned 1 to 6 nodes (mean 2), ranging from 1% to 100% of the total excised lymph nodes. The single largest focus of nodal LAM ranged from 1 to 9 mm (mean 4.3 mm) in 18 patients without evidence of persistent or recurrent nodal LAM. In the 1 patient with persistent local nodal LAM, the greatest diameter was 25 mm. Affected lymph node sites were regional pelvic and retroperitoneal chains routinely sampled in staging operations. An immunohistochemical panel of HMB45, A103, and β-catenin was evaluated in 18 cases. HMB45 showed strong but usually focal staining in every case compared with A103, which was very focally expressed (39%) or negative. β-catenin showed strong, diffuse cytoplasmic and membranous (non-nuclear) reactivity in 100% of cases. At the last clinic visit, all 19 patients had no manifestations of pulmonary LAM. In an absence of signs of symptoms of extranodal LAM, patients with incidentally discovered nodal LAM smaller than 10 mm are not at risk of developing pulmonary LAM.
淋巴结肌瘤病（LAM）是血管周上皮样细胞增生性病变，通常累及肺，表现为一种低级别、破坏性和进行性疾病，也可以发生于淋巴结及其它器官。因妇科肿瘤分期而行淋巴结切除的检查中有时会偶然发现LAM。到目前为止，关于偶然发现的淋巴结LAM在随后肺LAM发生中的临床意义，还没有研究。我们对本单位诊断的19例淋巴结LAM进行了研究。随访了所有的病人，随访时间3~123个月（平均 33.8个月）。病人皆为女性，年龄35~71岁（平均 56.3岁）。19例均无结节性硬化、肾血管平滑肌脂肪瘤或肺LAM的病史。病变累及1~6个淋巴结（平均 2个），病变范围占所有送检淋巴结的1%~100%。18例随访无持续或复发淋巴结LAM的病人中，单个最大病变灶范围1~9mm（平均 4.3mm）。1例随访有局部持续性淋巴结LAM者病变最大径为25mm。受累淋巴结部位为清扫手术常规送检的盆腔及腹膜后淋巴结。18例行HMB45、 A103和β-catenin的免疫组化检查：HMB45显示阳性，每例均呈灶状阳性，而A103仅呈小灶状表达（39%）或阴性， β-catenin显示阳性，100%呈弥漫性胞浆及胞膜（非核）表达。最近的临床随访，19例无一有肺LAM的表现。偶然发现的且病灶小于10mm的淋巴结LAM病人，缺乏结外LAM的症状，无进展为肺LAM的风险。