Department of Respiratory Medicine, Juntendo University, School of Medicine, 2-1-1 Hongo, Bunkyo-Ku, Tokyo 113-8421, Japan.
Eur J Radiol. 2012 Jun;81(6):1340-6. doi: 10.1016/j.ejrad.2011.03.039. Epub 2011 May 7.
Since Birt-Hogg-Dubé syndrome (BHDS) and lymphangioleiomyomatosis (LAM) share some clinical manifestations (multiple pulmonary cysts with pneumothorax, renal tumors, and sometimes skin lesions), the differential diagnosis of the two diseases becomes problem especially in female patients. This study aims to quantify pulmonary cysts in computed tomography (CT) of females with BHDS and those with LAM and also to identify the independent parameters for differentiating the two diseases.
Fourteen patients with BHDS and 52 with LAM were studied. In CT scans, lung fields were defined as areas with fewer than -200 Hounsfield units (HU) and pulmonary cysts as areas consisting of 10 or more consecutive pixels with fewer than -960 HU. The extent, number, size and circularity of cysts were calculated by using hand-made software and compared between the two diseases. Moreover, the lung fields were divided into six zones and analyzed for the distribution of cysts. Finally, a stepwise discriminant analysis employing quantitative measurements of cysts and clinical features was performed.
The two diseases were significantly different in all quantitative measurements of cysts. Stepwise discriminant analysis accepted the following four variables: the family history of pneumothorax within the second degree relatives, lower-medial zone predominance of cysts, diffusing capacity and mean size of cysts in this order.
The quantitative characteristics of pulmonary cysts are significantly different between BHDS and LAM. The independent parameters for differentiating the two diseases are the family history of pneumothorax, zonal predominance of cysts, diffusing capacity and size of cysts.
Birt-Hogg-Dubé 综合征（BHDS）和淋巴管平滑肌瘤病（LAM）具有一些相似的临床表现（多发性肺囊肿伴气胸、肾肿瘤，有时还有皮肤病变），因此两种疾病的鉴别诊断尤其在女性患者中存在问题。本研究旨在定量比较 BHDS 和 LAM 女性患者 CT 中的肺囊肿，并识别可用于区分这两种疾病的独立参数。
研究了 14 例 BHDS 患者和 52 例 LAM 患者。在 CT 扫描中，肺区定义为 Hounsfield 单位（HU）值低于-200 的区域，肺囊肿定义为 10 个或更多连续 HU 值低于-960 的像素区域。使用手工软件计算囊肿的范围、数量、大小和圆度，并比较两种疾病之间的差异。此外，将肺区分为六个区，并分析囊肿的分布。最后，采用包含囊肿和临床特征的定量测量的逐步判别分析。
两种疾病在所有囊肿的定量测量方面均存在显著差异。逐步判别分析接受了以下四个变量：二级亲属气胸家族史、中下肺区囊肿为主、弥散量和囊肿平均大小。
BHDS 和 LAM 之间肺囊肿的定量特征存在显著差异。区分这两种疾病的独立参数是气胸家族史、囊肿分布区、弥散量和囊肿大小。
