[Lymphangioleiomyomatosis]

Pulmonary lymphangioleiomyomatosis (LAM): A literature overview and case report

Lymphangioleiomyomatosis is a rare multisystem disease associated with genetic mutations. The disease usually occurs in women of childbearing age and is characterized by infiltration of immature smooth muscle cells into the lungs, airways, and axial lymphatic systems of the chest and abdomen. The disease often destroys lung parenchyma and produces air cysts. Lymphangioleiomyomatosis cell infiltration of the lymphatic axis can affect hilar lymph nodes, mediastinal ganglia, and extrathoracic lymph nodes. The disease can cause lymphatic dilation in the lungs and thoracic ducts, causing chylous effusion into the pleural or abdominal cavities. Invasion of cells into the walls of pulmonary veins can lead to venous obstruction and pulmonary venous hypertension with hemoptysis. Most patients present with cough, dyspnea, pneumothorax, hemoptysis, and abnormal lung function. Definitive diagnosis is usually based on histopathology and immunohistochemistry. We present a case of LAM in a 36-year-old female patient who was confirmed by specimens obtained from pneumothorax surgery and positive immunohistochemical staining with HMB-45.

[Lung metastases of pancreatic adenocarcinoma: Watch for the second train!]

Pulmonary metastases due to a pancreatic cancer are difficult to diagnose and demonstrate a wide range of radiological patterns. We report the case of a 37-year-old female patient, without past medical history, with multicystic lung disease in a context of chronic abdominal pain, fatigue and weight loss. After several months of diagnostic delay, pathological examination of surgical lung biopsies led to the diagnosis of secondary deposits of pancreatic cancer. The clinical and radiogical situation deteriorated quickly with the development of alveolar consolidation and Aspergillus superinfection was then diagnosed. This case illustrates the value of an early decision to undertake surgical lung biopsy in the work-up of multicystic lung disease when cancer is suspected. In addition, in the specific context of cancer, faced with clinical and/or radiological deterioration, it is essential to look for infection, particularly aspergillosis.

[Pulmonary lymphangioleiomyomatosis: From pathogenesis to management]

INTRODUCTION

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease affecting mainly young women.

BACKGROUND

The respiratory manifestations are characterized by a progressive cystic destruction of the lung parenchyma. Extrapulmonary involvement includes benign renal tumours called angiomyolipomas and abdominal lymphatic masses called lymphangioleiomyomas. At the pathological level, the cellular proliferation found in LAM is in part due to the presence of mutations in the tumour suppressor genes TSC1 and TSC2 (Tuberous Sclerosis Complex). These mutations lead to the activation of the mTOR pathway, which is currently the main therapeutic target. mTOR inhibitors such as sirolimus or everolimus have shown a beneficial effect on the decline in pulmonary function and a reduction of angiomyolipoma size, but are necessary in only some patients.

PERSPECTIVES

LAM cells have migratory properties mediated by the formation of new lymphatic vessels. They are also able to secrete metalloproteases, which enhance their invasiveness. Moreover, the expression of estrogen and progesterone receptors by LAM cells suggests a possible role for sex hormones in the pathogenesis of the disease.

CONCLUSION

A better understanding of mTOR-independent mechanisms would allow the development of novel therapeutic approaches.

[Pulmonary lymphangioleiomyomatosis of unusual revelation during multiple sclerosis]

La lymphangioléiomyomatose pulmonaire est une pathologie rare de la femme jeune, caractérisée par une prolifération de cellules musculaires lisses immatures, aboutissant à la destruction kystique des poumons avec possibilité d’évolution vers l'insuffisance respiratoire chronique. La découverte est souvent fortuite lors de la prise en charge d'une autre pathologie pulmonaire. Son association à une sclérose en plaque n'a jamais été rapportée, de même que l'embolie pulmonaire in situ comme manifestation inaugurale. Nous rapportons l'observation d'une patiente âgée de 39 ans, suivie pour sclérose en plaque depuis 20 ans, chez qui le diagnostic d'une lymphangioléiomyomatose pulmonaire a été posé, à l'occasion d'une broncho-pneumopathie bilatérale avec une embolie pulmonaire associée motivant la réalisation d'un angioscanner thoracique.