muramidase and Mesothelioma

Sections of primary lung carcinomas, lung metastases, mesotheliomas, and lung metastases of some rare mesenchymal tumors were incubated with different cytokeratin (CK), vimentin, desmin, and tissue polypeptide antigen (TPA) antibodies and with antibodies reactive with different hormones (ACTH, PTH, alpha-HCG, Calcitonin CT), CEA, carcinoma-associated antigen (CA1), secretory component (SC), neuron-specific enolase (NSE), alpha-1-antitrypsin (alpha-1-AT), lysozyme (lyso), and S-100 protein (S 100). CK antibodies derived from a 49 kD (reactive with simple epithelia [SE]) and a 67 kD CK polypeptide fraction (reaction with complex epithelia [CE] were useful differentiation markers for the four major groups of lung carcinomas. In one half of small cell carcinomas a positive reaction with NSE antibodies was found. S 100 and SC were good markers for papillary and bronchioloalveolar adenocarcinomas, whereas CEA was less important because of its reactivity with different types of lung carcinomas. To discern clear cell carcinomas of lung and renal origin a positive reaction with vimentin antibodies (some renal but not lung types) and with CA1 (no renal but all lung types) seemed to be useful. All hormone antibodies were of no importance as markers for difficult differential diagnosis, because positive reactivities were found in cases from every major carcinoma group. In addition, a Ca2+-activated adenosine triphosphatase (ATPase) was found in mesotheliomas but not in papillary adenocarcinomas.

Topics: Adenocarcinoma; Carcinoembryonic Antigen; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cell Differentiation; Desmin; Diagnosis, Differential; Histocytochemistry; Hormones; Humans; Immunologic Techniques; Keratins; Kidney Neoplasms; Lung Neoplasms; Mesothelioma; Muramidase; Neoplasm Metastasis; Peptides; Phosphopyruvate Hydratase; Pleural Neoplasms; S100 Proteins; Secretory Component; Tissue Polypeptide Antigen; Vimentin

In pleural biopsy specimens and histological sections from the fibrin clots of pleural fluid aspirates it may be difficult to distinguish reactive mesothelial cells from malignant mesothelial cells and metastatic carcinoma. Reactive pleurisy with effusion is usually associated with loss of cohesion and exfoliation of mesothelial cells, which is consistent with the hypothesis that they act as facultative histiocytes. A series of biopsy specimens and sections of clots from benign and malignant pleural effusions have been stained by the immunoperoxidase technique for the histiocytic markers alpha 1-antitrypsin, alpha 1-antichymotrypsin, and lysozyme (muramidase). Eight cases of mesothelioma were included. Mesothelial cells when seen as a monolayer lining the pleural surface were negative. Reactive mesothelial cells, usually seen as exfoliated cells, were consistently strongly positive for alpha 1-antichymotrypsin and more variably for alpha 1-antitrypsin and lysozyme. Malignant cells, whether from carcinoma or from mesothelioma, were usually but not always negative. Consequently immunohistochemical staining for alpha 1-antichymotrypsin is often helpful in distinguishing reactive mesothelial cells from malignant cells.

Topics: alpha 1-Antichymotrypsin; alpha 1-Antitrypsin; Biopsy; Biopsy, Needle; Chymotrypsin; Humans; Immunoenzyme Techniques; Mesothelioma; Muramidase; Pleura; Pleural Effusion; Pleural Neoplasms; Pleurisy