The first symptoms of LAM, such as shortness of breath during exercise, coughing and chest pain, usually occur between the ages of 25 and 35 years [1] [2]. Because LAM is rare and its onset insidiously, the symptoms may be misdiagnosed as asthma, pulmonary emphysema, chronic bronchitis, chronic obstructive pulmonary disease or sarcoidosis and the correct diagnosis may be delayed for several years [1] [3]. As the disease progresses, progressive dyspnea, pneumothorax, and chylothorax occur [4]. LAM can lead to chronic respiratory insufficiency. Other possible symptoms include chylous ascites, abdominal and thoracic lymphadenopathy and abdominal tumors including angiomyolipomas of the kidney and lymphangiomyomas [5]. TSC-LAM has symptoms of TSC.

The physical examination is often nonspecific but may reveal evidence of pleural effusion, ascites, pericardial effusion or pneumothorax, if present. High-resolution computed tomography (HR-CT) is the most sensitive method for diagnosing LAM. The typical findings are diffuse round, thin-walled cysts of varying sizes evenly distributed in all lung fields [3]. Other imaging results depend on the affected structures. Pulmonary function testing may be normal or may show obstructive, restrictive, or mixed patterns [5]. An increase of serum vascular endothelial growth factor D (VEGF-D) greater than 800 mg/L is common [6] [7] [8]. A LAM diagnosis without lung biopsy can be made in patients with typical cystic changes on pulmonary HR-CT scanning and findings of tuberous sclerosis, angiomyolipoma, lymphangioleiomyoma, thoracic or abdominal chylous effusion or serum VEGF-D > 800 mg/L, otherwise, a lung biopsy may be necessary [9].

General care depends on the manifestation and may include treatment of pleural effusions and ascites, and for airway disease bronchodilators and supplemental oxygen [10]. Sirolimus, an mTOR inhibitor, stabilizes lung function, reduces symptoms, the size of angiomyolipomas, lymphangioleiomyomas, and chylous effusions, and improves life quality [11] [12] [13] [14] [15] [16]. If lung function markedly declines, in some patients lung transplantation may be required [17].

Survival estimates vary widely. Sporadic LAM is generally more severe than TSC-LAM.

To date, the cause of LAM is not fully understood. LAM occurs sporadically (S-LAM) or as a complication of tuberous sclerosis (TSC-LAM) [18]. TSC is an autosomal dominant genetic disorder associated with development of hamartomas and dysplastic lesions in several organs.

Overall, the disease is very rare and the international frequency of LAM is unknown. TSC-LAM is present in up to 40% of women with tuberous sclerosis complex [19] [20].

The proliferation of abnormal cells leads to airflow obstruction, overdistention of distal air spaces, bullae, and the formation of pneumothoraces. Obstruction of lymphatics due to infiltration by smooth muscle cells may result in chylothorax, and chylous ascites.

No guidelines present.

Lymphangioleiomyomatosis (LAM) is a rare disease affecting lung, kidney, and axial lymphatics that occurs almost exclusively in women of reproductive age [5] [21]. LAM was first described in a patient affected by TSC who presented with bilateral spontaneous pneumothorax in 1918 [22] and the spontaneous form in a patient without TSC in 1937 [23]. The disorder is characterized by abnormal smooth muscle cell proliferation that results in functional obstruction of vessels, lymphatics, and airways.

Lymphangioleiomyomatosis (LAM) is a rare disease that usually affects women of childbearing age. It is characterized by an abnormal growth of cells, particularly of smooth muscle-like cells, in the lungs, lymphatic system and kidneys. There are two forms of the disorder -sporadic LAM (S-LAM) and TSC-LAM, which can be inherited with tuberous sclerosis complex.

Lymphangioleiomyomatosis may cause a wide variety of symptoms including progressive shortness of breath with exertion and recurrent episodes of collapsed lung, which are similar to those of other lung diseases such as asthma, emphysema, and bronchitis, thus the correct diagnosis is often delayed.

A high-resolution computed tomography (HRCT) chest scan, pulmonary function tests, a blood test for vascular endothelial growth factor D (VEGF-D) and in some cases a lung biopsy may be needed to provide an accurate diagnosis.

In some counties, the drug sirolimus (Rapamune) was approved to treat LAM. In addition, bronchodilators and supplemental oxygen may be necessary. Lung transplantation may be considered for patients with very advanced disease.

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