2025 Volume 64 Issue 4 Pages 188-194
Background : Lymphangioleiomyomatosis (LAM) is a rare disease characterized by the proliferation of smooth muscle-like cells (LAM cells) in the lungs and somatic lymph nodes, leading to the formation of multiple cysts in the lungs. Its estimated prevalence is 1.9 to 4.5 per million population in Japan. In this report, we describe a case of lymphangioleiomyomatosis.
Case : The patient was a woman in her 20s who presented with abdominal distention and morning-only chest pain. Her serum CA125 level was 858 U/ml and the serum D-dimer level was 13.8 μg/ml. CT and MRI of the thorax and abdomen revealed bilateral pleural effusions and ascites, as well as cyst formation in the retroperitoneum. Numerous small cysts, each measuring a few millimeters in diameter, were also observed in the lungs. Cytological examination and immunohistochemical analysis of prepared cell blocks of the ascitic and pleural fluid as also that of the contents of the cystic lesions in the retroperitoneum, revealed LAM cells. A needle biopsy of the retroperitoneal lymph nodes confirmed the presence of LAM cells. Based on these findings, along with the clinical presentation, we made the final diagnosis of LAM.
Conclusion : In patients with characteristic imaging findings, the diagnosis of LAM can be confirmed by identifying LAM cell clusters in pleural and ascitic fluid specimens. Familiarity with the cellular/immunohistochemical characteristics of LAM cells and the necessary immunohistochemical techniques is crucial, as it allows for the diagnosis to be obtained without invasive histopathology.
