[Pulmonary lymphangioleiomyomatosis. Immunohistochemical and ultrastructural study of two cases]. / La lymphangioléiomyomatose pulmonaire. Etude immunohistochimique et ultrastructurale de deux observations.

The authors report two cases of pulmonary lymphangioleiomyomatosis which were diagnosed by surgical biopsies. Immunohistochemical study showed positive staining of the smooth muscle cells using antibodies directed against smooth muscle actin, specific muscle actin, HMB45 and vimentin. Ultrastructural study showed some smooth muscle differentiation features, with numerous myofilaments and some dense bodies near the plasma membrane. In one case, the patient was treated by a double-lung transplantation. LAM is a non-familial disease occurring exclusively in females. The etiology is unknown. This disease can be complicated by chronic respiratory failure. Extrapulmonary sites are not rare, particularly in the uterus. Anti-estrogen treatment can slow the course of the disease. Lung transplantation is actually the only effective treatment at the present time therapy. The differential diagnosis of this disease is discussed.

Characterization of the smooth muscle cell infiltrate and associated connective matrix of lymphangiomyomatosis. Immunohistochemical and ultrastructural study of two cases.

Lymphangiomyomatosis (LAM) consists of smooth muscle (SM) cell proliferation of unknown origin involving the lymph nodes and the lung interstitium. From morphological studies showing both SM differentiation of the proliferating cells and lymphatic hyperplasia, hypotheses were suggested concerning the origin of the proliferation. Two cases of LAM were investigated by electron microscopy and immunohistochemistry; tissues were obtained by lymph node and open lung biopsies. Cytoplasmic and matrix protein markers were used in order to clarify the pattern of differentiation of the proliferating cells and to characterize their connective tissue environment. The proliferating cells present ultrastructural characteristics of SM cells; they contain vimentin, desmin, and alpha-SM actin and are devoid of Factor VIII, favouring a parieto-arterial origin. The connective tissue matrix inside the infiltrate is composed of interstitial collagens and basement membrane components. At the late stage of the disease, remodelling of the interstitial matrix accompanies the infiltrate and remains perilesional.

Role of elastic fiber degradation in emphysema-like lesions of pulmonary lymphangiomyomatosis.

To study the pulmonary structural remodeling in pulmonary lymphangiomyomatosis, electron microscopy and light and electron microscopic immunohistochemical observations for elastin and alpha 1-antitrypsin were performed on five open lung biopsy samples. Lung specimens showed emphysema-like changes in areas of abnormally accumulated smooth muscle cells. In the alveolar walls having accumulated smooth muscle cells, elastic fibers were decreased in number, disrupted, granular, and occasionally accumulated. Ultrastructurally, elastic fibers in areas of smooth muscle cell accumulation showed poorly outlined amorphous components and a few microfibrils, and occasionally showed electron-dense granular deposits in and around the amorphous components. Spiraling collagen fibrils were frequently found associated with these abnormal elastic fibers. Immunohistochemistry for elastin showed even staining of amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. alpha 1-Antitrypsin was also detected evenly in amorphous components of elastic fibers in the areas of smooth muscle cell accumulation. It is proposed that the emphysema-like lesions of lymphangiomyomatosis are mediated by the degradation of elastic fibers, and these degraded elastic fibers are related to an imbalance of the elastase/alpha 1-antitrypsin system similar to the probable pathogenesis of emphysema.

Immunohistochemical detection of steroid receptors in a case of pulmonary lymphangioleiomyomatosis.

Abnormal proliferation of smooth muscle cells in pulmonary lymphangioleiomyomatosis (LAM) is thought to be influenced by estrogen and progesterone. However, the results of previous studies using cytosolic methods to measure estrogen and progesterone receptor content in lung tissue from these patients have been inconsistent. We used immunohistochemical methods to study the tissue distribution of estrogen and progesterone receptors in LAM as well as in smooth muscle of several other organs, including histologically normal lung, colon, bladder, prostate, uterus, and uterine leiomyomas. Progesterone receptor was expressed strongly and estrogen receptor more weakly by the abnormal myoid cells of LAM. Hormone receptors were absent from all other constituents of lung tissue in our patient. These findings were similar to those in histologically normal myometrium and uterine leiomyomas. Although we found focal labeling of prostatic stromal cells with anti-progesterone receptor, no other smooth muscle tissue expressed either estrogen or progesterone receptor. We conclude that LAM is an abnormal proliferation of smooth muscle cells that express both estrogen and progesterone receptors.

[Retroperitoneal lymphangiomyomatosis. Immunohistochemical and ultrastructural study of a case]. / Linfangiomiomatosi ad esordio retroperitoneale. Studio immunoistochimico ed ultrastrutturale di un caso.

A case of retroperitoneal lymphangiomyomatosis occurring in a 34-year-old woman is reported. Alpha-smooth muscle actin and desmin were localized in the proliferating cells. Electron microscopy showed the presence of many thin perinuclear myofilaments with dense bodies. The differential diagnosis with leiomyosarcoma has been taken into consideration.

Pulmonary lymphangiomyomatosis. Report of a case with immunohistochemical and ultrastructural findings.

Pulmonary lymphangiomyomatosis is a rare disease characterized by wide-spread proliferation of smooth muscle cells around lymphatic and blood vessels, smaller airways and in the interstitium. Young women in the fertile status are almost exclusively affected. Spontaneous recurrent pneumothorax is the most important symptom. Chylous effusions are reported in 37.5% of cases. Our observation deals with a woman aged 43. Light- and electron-microscopic findings are described. Estrogen receptors have been detected on smooth muscle cells. Bilateral oophorectomy and treatment with progesterone were successful.

Pulmonary lymphangioleiomyomatosis and Bourneville's tuberous sclerosis with pulmonary involvement: the same disease?

The authors studied the ultrastructural morphology of the lung in one case of Bourneville's tuberous sclerosis with pulmonary involvement. The observations in this report are similar to those previously reported in pulmonary lymphangioleiomyomatosis and further emphasize the striking resemblance between the two diseases.