Langerhans cell histiocytosis (LCH) is a histiocytic neoplasm that can involve the lungs as single system (LCH-SSL) or multisystem disease (LCH-MSL). The role of full-body radiographic staging to determine whether patients have LCH-SSL or LCH-MSL is unclear. Long-term outcomes of LCH-SSL versus LCH-MSL and multisystem without lung involvement (LCH-MSNL) are unknown. A retrospective study of adult LCH patients seen at our center from January 2000 to 2020 was performed. In Part 1, we addressed utility of whole-body staging imaging among those presenting with isolated pulmonary signs or symptoms. Staging was defined as fluorodeoxyglucose positron emission tomography-computed tomography (CT) or whole-body CT obtained within 3 months of diagnosis. In Part 2, we examined the frequency of developing extra-pulmonary disease over time and mortality in patients with LCH-SSL. In Part 3, we compared the overall survival of LCH-SSL, LCH-MSL, and LCH-MSNL. Part 1: 240 patients with LCH were identified. A total of 112 (47%) had pulmonary signs or symptoms at presentation. Thirty-four (30%) underwent radiographic staging and only one showed evidence of extra-pulmonary disease. Part 2: 108 (45%) were LCH-SSL. Median follow-up duration of 4.5 years (95% confidence interval [CI]: 2.9–6.0). None developed extra-pulmonary disease. Part 3: 5-year survival: 94% (95% CI: 84%–98%) for LCH-SSL, 78% (95% CI: 59%–90%) for LCH-MSL, and 75% (95% CI: 53%–89%) for LCH-MSNL. LCH patients presenting with isolated pulmonary signs or symptoms rarely have extra-pulmonary involvement at the time of diagnosis and generally do not develop extra-pulmonary progression. LCH-SSL has the best overall survival, while LCH-MSL and LCH-MSNL have similar clinical outcomes.

中文翻译：

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朗格汉斯细胞组织细胞增生症伴孤立性和多系统疾病中的肺部受累：分期、自然病程和比较存活率

朗格汉斯细胞组织细胞增生症 (LCH) 是一种组织细胞肿瘤，可累及肺部为单系统 (LCH-SSL) 或多系统疾病 (LCH-MSL)。全身影像学分期在确定患者是否患有 LCH-SSL 或 LCH-MSL 方面的作用尚不清楚。LCH-SSL 与 LCH-MSL 和多系统无肺受累 (LCH-MSNL) 的长期结果尚不清楚。对 2000 年 1 月至 2020 年在我们中心就诊的成人 LCH 患者进行了回顾性研究。在第 1 部分中，我们讨论了全身分期成像在出现孤立肺部体征或症状的患者中的实用性。分期定义为氟脱氧葡萄糖正电子发射断层扫描计算机断层扫描 (CT) 或诊断后 3 个月内获得的全身 CT。在第 2 部分中，我们检查了 LCH-SSL 患者随时间推移发生肺外疾病的频率和死亡率。在第 3 部分中，我们比较了 LCH-SSL、LCH-MSL 和 LCH-MSNL 的总生存率。第 1 部分：确定了 240 名 LCH 患者。共有 112 人 (47%) 在就诊时有肺部体征或症状。三十四人（30%）接受了放射学分期，只有一人显示出肺外疾病的证据。第 2 部分：108 个 (45%) 是 LCH-SSL。中位随访时间为 4.5 年（95% 置信区间 [CI]：2.9-6.0）。没有人发生肺外疾病。第 3 部分：5 年生存率：LCH-SSL 为 94%（95% CI：84%–98%），LCH-MSL 为 78%（95% CI：59%–90%）和 75%（95%） CI：53%–89%）对于 LCH-MSNL。出现孤立的肺部体征或症状的 LCH 患者在诊断时很少有肺外受累，通常不会发生肺外进展。LCH-SSL 的总生存期最好，而 LCH-MSL 和 LCH-MSNL 的临床结果相似。