Localized mesothelioma of the pleura; a review with six new cases.

Abstract

Localized mesothelioma of the pleura is a relatively rare tumor; a review of cases indicates, however, that this diagnosis can justifiably be made in the presence of certain roentgenologic findings. The condition was first established as an entity by Stout and Murray in 1942 (1). Since that time approximately 50 cases have been reported in the English literature (2–8). Localized mesothelioma must not be confused with two other tumors, which are also referred to as mesothelioma: diffuse mesothelioma and mesothelioma of the male and female genital tracts. Diffuse mesothelioma is well known. It is a malignant neoplasm which invades locally, spreading widely over mesothelial surfaces, but rarely metastasizing to distant parts of the body. This tumor characteristically forms tubules lined by anaplastic cells. It most frequently arises from the peritoneum, though the pleura or pericardium may sometimes be the site of origin. Mesothelioma of the male and female genital tracts; unlike the diffuse and localized mesotheliomas of the pleura, pericardium, and peritoneum, tends to form small nodules composed of tubules lined by cells which secrete a mucoid substance. Most authors regard these tumors as of mesothelial origin, though some consider them adenomatoid tumors or true adenomas (2). Mesotheliomas of the genital tract are generally considered to be benign. Horn and Lewis (9), however, in a review of the literature indicate that 1 of 27 reported cases may have been malignant. Until recently, all recorded cases of localized mesothelioma were considered to be of the fibrous type. Yesner and Hurwitz (8), however, reported a localized mesothelial tumor which they and the Armed Forces Institute of Pathology believed to be of epithelial type. For this reason the group of tumors to be described here will be referred to simply as localized mesothelioma, with recognition of the fact that both fibrous and epithelial types may exist. Symptoms And Clinical Findings Some cases of mesothelioma of the pleura have been entirely asymptomatic. In others, there have been slight symptoms, such as a mild cough and a feeling of heaviness and vague discomfort in the chest. Clagett et al. (4) observed that 7 of 24 patients gave histories of recurrent chills and fever. Dyspnea, weight loss, malaise, chest pain, etc., may be present, depending upon the size and location of the mass. A report by Wierman, Clagett, and MeDonald (10) indicates that localized pleural mesothelioma produces joint signs and symptoms, such as stiffness and pain and occasionally swelling and tenderness, in a higher percentage of cases than any other intrathoracic mass. In one series, 16 of 24 patients had symptoms and/or physical signs referable to the joints; 11 of these showed clubbing of digits (4).