BACKGROUND In a previous study, morphometry and multivariate cluster analysis was performed on 97 lesions. These consisted of atypical adenomatous hyperplasia (AAH), considered to be an important lesion corresponding to a step of carcinogenesis for adenocarcinoma of the human lung, Clara cell type, and type 2 pneumocyte type adenocarcinomas. Although AAH and the two types of adenocarcinoma were re-classified into three clusters and AAH was defined in clear morphologic terms, the biologic nature of AAH has yet to be clarified. In the present study, immunohistochemical analysis was performed to gain a deeper understanding of the relationship between AAH and the two types of adenocarcinoma, and to compare the results with those obtained by morphometry. METHODS The 97 lesions analyzed by morphometry were submitted to immunohistochemical analyses using antibodies against surfactant apoprotein A, urine protein 1, carcinoembryonic antigen and cytochrome P-450s (1A1-2, 2B1-2, 2E1). Also examined, as controls, were 17 lesions with adenomatous hyperplasia (AH), a non-neoplastic reactive change of bronchiolo-alveolar cells, 30 areas of normal Clara cells, and 36 areas of normal type 2 pneumocytes. The immunoreactivity was graded by introducing a semi-quantitative scoring system. RESULTS Immunohistochemically, AAHs behaved quite similarly to the lesions classified as Clara cell type or type 2 pneumocyte type adenocarcinomas. For any of the antibodies employed, no significant difference in immunoreactivity was demonstrated among these lesions. CONCLUSIONS The results suggest, in accordance with our previous morphometry, that AAH is a lesion closely related with Clara cell type and type 2 pneumocyte type adenocarcinomas, probably as their common precursor. However, the two types of adenocarcinomas, despite their characteristic morphologic features, are indistinguishable using the biological indicators applied in this study. Cancer 1996; 77:665-74.
TAKAHASHI, H., TSUDA, N., TEZUKA, F. and OKABE, H. Immunohistochemical Localization of Carcinoembryonic Antigen in Carcinoma in Pleomorphic Adenoma of Salivary Gland: Use in the Diagnosis of Benign and Malignant Lesions. Tohoku J. exp. Med., 1986, 149 (3) 329-340-The localization of carcinoembryonic antigen (CEA) and lysozyme (LZM) was immunohistochemically studied in 34 carcinomas arising in benign pleomorphic adenomas and 25 normal salivary glands in order to assess its potential diagnostic value. (1) CEA in the normal salivary gland was located in luminal cell membranes of intercalated duct cells and serous acinar cells. (2) Strongly positive cell surface and intraluminal staining of CEA appeared in the areas of gland-forming pattern in pleomorphic adenoma. (3) CEA activity was detected in 7/9 cases (78%) of adenocarcinoma, 10/11 cases (91%) of epidermoid carcinoma, 3/8 cases (38%) of anaplastic carcinoma, 5/5 cases (100%) of mucoepidermoid carcinoma, and 1/1 case (100%) of adenoid cystic carcinoma. CEA was always present in the cytoplasm of epithelial cells and luminal contents of neoplastic glands. CEA in epidermoid carcinoma may occasionally react strongly in the cytoplasm. (4) Lysozyme-immunoreactivity was detected in the cytoplasm of intercalated duct cells and serous acinar cells of the normal salivary gland but little or no LZM was observed in any of the tumors. These results suggest that the presence of CEA could be a useful marker that provides valuable information for the differential diagnosis between benign and malignant areas of carcinoma in pleomorphic adenoma of the salivary gland. Moreover, LZM could be of valuable use for discriminating neoplastic from non-neoplastic tissue of salivary glands.
We report a rare case of solitary fibrous tumor of the parotid gland. A 47-year-old woman presented with a 3-year-history of left-sided subauricular swelling. Computed tomographic scans and magnetic resonance images revealed a well-defined and dumbbell-shaped mass, measuring about 30 mm in its greatest dimension, in the left parotid gland. Because the tumor occupied both superficial and deep lobes of the gland, she underwent total parotidectomy with preservation of the facial nerve. The microscopic finding showed short-spindle and ovoid cells arranged in a haphazard pattern with interspersed thin collagen fibrils. Immunohistochemically, the tumor cells were strongly positive for CD34, bcl-2 and vimentin, whereas stains for S-100, cytokeratin, smooth muscle actin, collagen type IV and CD117 (KIT) were negative. On the basis of these findings, the tumor was diagnosed as solitary fibrous tumor. Her post-operative course was uneventful, and she is currently free from disease 14 months after surgery. Diagnosis, clinical behavior and treatment of solitary fibrous tumor are reviewed from perusal of the literature.
