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Immunohistochemical detection of P53 protein is not associated with a poor prognosis in non-small-cell lung cancer
Abstracts/Lung
Cancer
typical biphasic, Regaud-like morphology might be inapparent. In accordance with the previously reported cases of pulmonary lymphoepithelioma-like carcinoma in Caucasian patients, the present study found no evidence of the Epstein-Barr virus genome in neoplastic cells with in situ hybridization. Transferrin receptor expression in nonsmall cell lung cancer: Histopathologic and clinical correlates Whitney JF, Clark JM, GriBin TW, Gautam S, Leslie KO. Deparhnent ofParhology, University of Vermont, Burlington, ~05405-0068. Cancer 1995;76:20-5. Background. In the search for tumor-related antigens with survivalpredictive value, previous studies have yielded varied conclusions regarding the expression of one such antigen, the transferrin receptor in lung cancer. The goal of this study was to define the frequency of expression of transferrin receptor in lung cancer specimens and gather preliminary data regarding the prognostic value of this tumor-related antigen. Mefhoa!s. Tissue immunoreactitity was studied with a routine monoclonal antibody to transferrin receptor in patients with nonsmall cell lung cancer who underwent surgical resection at the Medical Center Hospital of Vermont during the period from January, 1988, to May, 1991. Results. The study group consisted of 32 patients (21 males and 1 I females) with an average follow-up length of 27 months (standard deviation of I6 months). There were 17 patients with adenocarcinoma, 14 with squamous cell carcinoma, and I with large cell carcinoma. At the end of data accumulation, a total of 16 deaths had been recorded (8 with squamous cell, 8 with adenocarcinoma). Normal lung tissue did not stain for transferrin receptor; however, 13 of 17 (76%) adenocarcinomas, 13 of I4 (93%) squamous cell carcinomas, and the 1 large cell carcinoma stained positively for transfenin receptor. Straining for transferrin receptor was graded according to pattern and intensity and categorized as absent-weak or strong. Survival analysis was performed to evaluate patient outcome based on a variety of clinical and experimentally determined characteristics. Groups based on N-status (NO vs. Nl + N2, P = 0.08). stage (Stage 1 vs. Stage 2 + 3, P = O.l3), age (younger than 60 vs. 60 years or older, P = 0.09), and transferrin receptor staining (absent weak vs. strong, P = 0.14) achieved nearly significant differences in survival. Further analysis of the differences in survival for groupings based on transferrin receptor staining found that these differences in survival reached significance for patients with larger tumors (T2 or T3, P = 0.02). Conclusions. Transferrin receptor is expressed in the majority of lung canters and the presence of transferrin receptor in nonsmall cell lung cancers may be an indicator of pwrer prognosis in certain groups of patients.
Small adenocarcinoma of the lung: Histologic characteristics and prognosis Noguchi M, Morikawa A, Kawasaki M, Matsuno Y, Yamada T, Hirohashi S et al. Palhology Division. National Cancer C1,: Research Inst., I-I, Tmkiji S-Chome, Chuo-ku, Tokyo 104. Cancer 1995;75:284452. Background. Although there are many reported prognostic indicators for pulmonary adenocarcinoma, the clinicopathologic characteristics and prognostic factors of early stage adenocarcinoma have not been evaluated fully, except for several studies of nonmucinous and sclerosing bronchioloalveolar carcinoma. Method. Two hundred thirty-six surgically resected small peripheral adenocarcinomas measuring 2 cm or less in greatest dimension were reviewed using a simple histologic classification of six types based on tumor groti patterns. Results. m A (localized bronchioloalveolar carcinoma FBAC]) (n = 14) revealed replacement growth of alveolar-lining epithelial cells with a relatively thin stroma. In type B (LBAC with loci of structural collapse of alveoli)
13 (1995)
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197
(n = 14), fibrotic foci due to alveolar collapse were observed in tumors of LBAC. Qpe C [LBAC with foci of active fibroblastic proliferation) (n = 14 I) was the largest group in this study, and foci of active fibroblastic proliferation were evident. Type D (poorly differentiated adenocarcinoma), type E (tubular adenocarcinoma) and type F (papillary adenocarcinoma with a compressive growth pattern) (n = 61) showed compressive and expanding growth. Types A and B showed no lymph node metastasis and the most favorable prognosis (100% 5-year survival) of the six types. Conclusion. Histologic types A and B are thought to be in situ peripheral adenocarcinoma, whereas type C appears to be an advanced stage of types A and B. Conversely, types D, E, and F are small advanced adenccarcinomas with a less favorable prognosis. X-ray microanalysis of peripheral lung carcinoma Terzalcis JA. Department of Pathology. Lenox Hill Hospital, 100 East ??thS&eet, New York, NY10021-1883. Ultrastruct Pathol 1995;19:16773. A total of 15 cases of peripherally located lung carcinomas associated with scar (scar carcinoma) were studied by light microscopy and electron microscopy with energydispersive X-my microanalysis (XMA). Results were compared to those of three autopsy lungs without significant pulmonary findings that served as controls. Fibrosis with scar formation characterized the 15 tumor cases. Particulate depositions including doubly refractile particles were also increased in the tumor group. XMA identified 15 elements with great complexity of particulate composition. Silicon was the most prominent element and was found in 16 of 18 cases studied. Kaolinite, feldspar, talc, muscovite, and silica were recognized. The fibrogenic properties of silicate compounds were emphasized, including their prominence in the lung tumor group. While the important concept of tumor desmoplasia was recognized, the study showed significant fibrosis in relation to fibrogenic materials, which undoubtedly preceded the appearance of the tumors. Also noted were the carcinogens uranium, cadmium, chromium, nickel, and arsenic, some of which were previously described as minor constituents of naturally occurring minerals. Immunohistochemical detection of PS3 protein is not associated with a poor prognosis in non-small-cell lung cancer Passlick B, Izbicki JR, Haussinger K, Thetter 0, Pantel K. Departmeal of Surgery, Universitats~ankenhaus Eppendorl; Martinis& 52, 20246 Hambuqy. J Thorac Cardiovasc Surg 1995;109:1205-11. Immunohistochemical detection of the ~53 gene product by monoclonal antibodies has been shown to be associated with a poor clinical outcome in carcinomas of the breast and stomach. Because the prognostic relevance of p53 immunosiaining in lung cancer is still under debate, we studied the expression pattern and clinical significance of such staining in 73 patients with operable non-small~ll lung cancer. ~53 expression was detected on frozen sections with the use of monoclonal antibody ~1801, which recognizes both the wild-type and mutant gene product (alkaline phosphatase-antialkaline phosphatase method). A tumor was considered ~53 positive if more than 1% of the tumor cells were stained. The ~53 expression pattern was compared with clinicopathologic parameters, and analysis of follow-up, based on the data of 65 patients, was done by a log rank test (median observation time, 780 days). Nuclear ~53 staining was detected in 33 of 73 nonsmall- cell lung cancers (45.2%). Comparison with cliniwpathologic parameters demonstrated that the ~53 protein was detected more frequently in younger patients (younger tban 50 years, p = 0.014). whereas no correlation was found with sex, tumor differentiation, tumor histologic type, or TNM stage. Surprisingly, follow-up analysis revealed that p53 staining was associated with an increased rate of disease-free survival, especially in patients with early stage tumor disease @ = 0.004)
198
Abstracts/Lung
Cancer
and in male patients @ = 0.023). Counter to previous studies in other solid tumors, immunocytochemical detection of ~53 expression does not predict a poor clinical outcome in non- smallcell lung cancer. In early-stage lung cancer it might be associated with an impruved diseasefree survival, which suggests that the majority of the detected protein inherits the wild-type tumor suppressor function.
High prevalence of bcl-2 oncoprotein expression in small cell lung cancer Higaahiyama M, Doi 0, Kodama K, Yokouchi H, Tateishi R. Department of Thoracic Surgery, The Centerfor Adult Diseases, Nakamichi 1-3-3. Higashinai-ku. Osaka, 537. Anticancer Res 1995;15:503-5. Bcl-2 oncoprotein, a member of a new category of oncogenes associated with the regulation of programmed cell death (apoptosis), has been considered to be involved in biological processes such as tumorigenesis and tumor development. To determine the role of bcl-2 oncoprotein in lung cancer, we preliminarily examined the expression of this protein in various histological types. Inuuunohistochemical staining using monoclonal bcl-2 onmprotein antibody was performed in surgically resected frozen specimens. Bcl-2 staining was seen in nine of 13 small cell lung cancers (69%) while only 18 out of 69 non-small cell lung cancers (26%) expressed bcl-2 oncoprotein, showing a significantly increased incidence of bcl-2 onmprotein expression in the former histological type. Considering the greater aggressiveness of small cell lung cancer compared to non-small cell lung cancer, the possibility exists that the high prevalence ofbcl-2 oncoprotein expression in small cell lung cancer is closely associated with tumorigenesis and tumor development.
Distribution of the carbohydrate antigens, DU-PAN-2 and CA19-9, in tumors of the lung Ohshio G, Yamaki K, Imamura T, Suwa H, Chang CY, Wada H et al. Department ofSwge~, Faculty OfMedicine, Kyoto lJniversi& Shogoin Kawara-cho 34, Sakyo-ku, Kyoto 606. Tumori 1995;81:67-73. Aims and backgrtxmd: The carbohydrate chains of malignant OZIIS appear to be related to oncofetal differentiation. The serum levels Of CAl9-9 have been reported to be evaluated in some patients with lung carcinomas, however, the distribution of carbohydrate antigens were not precisely described. We have investigated in this study the distribution of DU-PAN-2 and CAl9-9 antigens in lung tumors. Methods: Ninety-five specimens of lung tumors were selected from surgical specimens. The expression of DU-PAN-2 and CAl9-9 were studied by immunohystochemical techniques. The relationship between the expression of these antigens and the classification or the differentiation degree of the tumors were examined. Results: DU-PAN-2 or CAl9-9 antigens were detected in 41 (54%) and 45 (59%) cases of the 76 malignant epithelial tumors investigated. These antigens were detected in all types of malignant epithelial tumors, including squamous cell carcinomas, where they were mainly localized to the entire cell surface of malignant cells. In adenocarcinomas, huge cell carcinomas and small cell carcinomas, however, these antigens were commonly detected both on the cell membrane and in the cytoplasm. There was positive correlation between the degree of differentiation and DU-PAN2, but not CAl9-9 expression. Among the non-epithelial tumors investigated, those antigens were detected in pulmonary blastomas but not in mesotheliomas. Conclusions: Immunohistochemical studies for DU-PAN-2 and CAl9-9 are useful for defining characteristics of the lung tumors. DU-PAN-2 could be a marker for differentiating between malignant epitbelial tumors and mesotheliomas.
13 (1995)
185-232
Lung tumors of uncertain histogeneais Shimosato Y. Clinical Laboratories Division, National Cancer Center Hospital, 5-1-l. Tsukiji Chuo-ku, Tokyo 104. Semin Diagn Pathol 1995;12:185-92. Unusual lung tumors of uncertain origin have been described briefly concerning benign clear cell (sugar) tumor and, in more detail, concerning pneumocytoma (so-called sclerosing hemangioma). Melanocytic differentiation of clear cell tumor, which is peculiar to the lung, has been suggested recently. Sclerosing hemangioma, also unique to the lung is now mnsidered to be a tumor (neoplasm) related to alveolar epithelial cells. It shows invasive growth and multiplicity (or aerogenous metastasis), but is very rarely capable of lymph node metastasis. It should be designated as pneumocytoma. Lung tumors derived from ectopic tissues Man&v&y AM. Patholo@Laborato?yMedicine Dept., Cedars-Sinai Medical Center 8700 Beverly Blvd. Los Angeles, CA 90048. Semin Diagn Pathol 1995;12:172-84. Ectopic tissues rarely occur in the lung. They include endometriosis, neuroglial tissue, thyroid, pancreas, and adrenal, Choristomas are very rare developmental anomalies derived from these ectopic tissues, They develop as a mass composed of histologically normal tissues that are heterotopic in the lung. wous intrapulmonary neoplasms also rarely develop from ectopic tissues. They include malignant melanoma, thymoma, meningioma, glomus tumor, germ cell neoplasms (choriocarcinoma and teratoma), and ependymoma. The clinimpathological features of these unusual pulmonary neoplasms are discussed. Malignant mixed epitheiial/mesenchymal neoplasms of the lung Bcrho hJ, Moran CA, Suster S. Department ofPathoiogy, Mount Sinai Medical Center: 4300AIton Rd. Miami Beach, FL 33140. Semin Diagn Path01 1995;12:123-39. The existence of biphasic neoplasms occurring primarily in the lung is a well-known albeit rare event. The spectmm of malignant tumors displaying a mixed epitheliabmesenchymal growth pattern is rather narrow when these tumors occur primarily in the lung. The two most often encountered neoplasms showing features of epithelial and mesenchymal differentiation are carcinosarcomas and pulmonary blastomas. Tumors with analogous features are of ubiquitous distribution in the human body and have been described in numerous other organs, including the gastrointestinal tract, the genitourinary tract, and the endocrine system. Although the histopathologic features of these tumors may seem simple in most cases, there appear to be numerous pitfalls in their diagnosis; gray areas still remain in the characterization of these tumors, because a certain degree of overlap may be encountered with these two conditions. Such problems are understandable because the incidence of these tumors in the general population is very rare. Therefore, one is expected to find divergent points of view regarding these neoplasms. It is of importance, however, to unity criteria not only for diagnostic purposes, but also to determine the prevalence and behavior of these neoplasms, because such information may provide a rationale for adjustment and improvement in the treatment and diagnosis of these unusual neoplasms. We will review past and current concepts regarding these unusual tumors, as well as their more salient histopathologic features. Primary salivary gland-type tumors of the lung Moran CA. Pulmonary/MedrastinaI Pathol. Dept., Armed Forces Institute of Pathology, Washington, DC 20306-6000. Semin Diagn Path01 1995;12:106-22. Primary pulmonary neoplasms that bear similar histopathologic features to those seen in salivary glands are rare. Although their presence
Cancer
typical biphasic, Regaud-like morphology might be inapparent. In accordance with the previously reported cases of pulmonary lymphoepithelioma-like carcinoma in Caucasian patients, the present study found no evidence of the Epstein-Barr virus genome in neoplastic cells with in situ hybridization. Transferrin receptor expression in nonsmall cell lung cancer: Histopathologic and clinical correlates Whitney JF, Clark JM, GriBin TW, Gautam S, Leslie KO. Deparhnent ofParhology, University of Vermont, Burlington, ~05405-0068. Cancer 1995;76:20-5. Background. In the search for tumor-related antigens with survivalpredictive value, previous studies have yielded varied conclusions regarding the expression of one such antigen, the transferrin receptor in lung cancer. The goal of this study was to define the frequency of expression of transferrin receptor in lung cancer specimens and gather preliminary data regarding the prognostic value of this tumor-related antigen. Mefhoa!s. Tissue immunoreactitity was studied with a routine monoclonal antibody to transferrin receptor in patients with nonsmall cell lung cancer who underwent surgical resection at the Medical Center Hospital of Vermont during the period from January, 1988, to May, 1991. Results. The study group consisted of 32 patients (21 males and 1 I females) with an average follow-up length of 27 months (standard deviation of I6 months). There were 17 patients with adenocarcinoma, 14 with squamous cell carcinoma, and I with large cell carcinoma. At the end of data accumulation, a total of 16 deaths had been recorded (8 with squamous cell, 8 with adenocarcinoma). Normal lung tissue did not stain for transferrin receptor; however, 13 of 17 (76%) adenocarcinomas, 13 of I4 (93%) squamous cell carcinomas, and the 1 large cell carcinoma stained positively for transfenin receptor. Straining for transferrin receptor was graded according to pattern and intensity and categorized as absent-weak or strong. Survival analysis was performed to evaluate patient outcome based on a variety of clinical and experimentally determined characteristics. Groups based on N-status (NO vs. Nl + N2, P = 0.08). stage (Stage 1 vs. Stage 2 + 3, P = O.l3), age (younger than 60 vs. 60 years or older, P = 0.09), and transferrin receptor staining (absent weak vs. strong, P = 0.14) achieved nearly significant differences in survival. Further analysis of the differences in survival for groupings based on transferrin receptor staining found that these differences in survival reached significance for patients with larger tumors (T2 or T3, P = 0.02). Conclusions. Transferrin receptor is expressed in the majority of lung canters and the presence of transferrin receptor in nonsmall cell lung cancers may be an indicator of pwrer prognosis in certain groups of patients.
Small adenocarcinoma of the lung: Histologic characteristics and prognosis Noguchi M, Morikawa A, Kawasaki M, Matsuno Y, Yamada T, Hirohashi S et al. Palhology Division. National Cancer C1,: Research Inst., I-I, Tmkiji S-Chome, Chuo-ku, Tokyo 104. Cancer 1995;75:284452. Background. Although there are many reported prognostic indicators for pulmonary adenocarcinoma, the clinicopathologic characteristics and prognostic factors of early stage adenocarcinoma have not been evaluated fully, except for several studies of nonmucinous and sclerosing bronchioloalveolar carcinoma. Method. Two hundred thirty-six surgically resected small peripheral adenocarcinomas measuring 2 cm or less in greatest dimension were reviewed using a simple histologic classification of six types based on tumor groti patterns. Results. m A (localized bronchioloalveolar carcinoma FBAC]) (n = 14) revealed replacement growth of alveolar-lining epithelial cells with a relatively thin stroma. In type B (LBAC with loci of structural collapse of alveoli)
13 (1995)
185-232
197
(n = 14), fibrotic foci due to alveolar collapse were observed in tumors of LBAC. Qpe C [LBAC with foci of active fibroblastic proliferation) (n = 14 I) was the largest group in this study, and foci of active fibroblastic proliferation were evident. Type D (poorly differentiated adenocarcinoma), type E (tubular adenocarcinoma) and type F (papillary adenocarcinoma with a compressive growth pattern) (n = 61) showed compressive and expanding growth. Types A and B showed no lymph node metastasis and the most favorable prognosis (100% 5-year survival) of the six types. Conclusion. Histologic types A and B are thought to be in situ peripheral adenocarcinoma, whereas type C appears to be an advanced stage of types A and B. Conversely, types D, E, and F are small advanced adenccarcinomas with a less favorable prognosis. X-ray microanalysis of peripheral lung carcinoma Terzalcis JA. Department of Pathology. Lenox Hill Hospital, 100 East ??thS&eet, New York, NY10021-1883. Ultrastruct Pathol 1995;19:16773. A total of 15 cases of peripherally located lung carcinomas associated with scar (scar carcinoma) were studied by light microscopy and electron microscopy with energydispersive X-my microanalysis (XMA). Results were compared to those of three autopsy lungs without significant pulmonary findings that served as controls. Fibrosis with scar formation characterized the 15 tumor cases. Particulate depositions including doubly refractile particles were also increased in the tumor group. XMA identified 15 elements with great complexity of particulate composition. Silicon was the most prominent element and was found in 16 of 18 cases studied. Kaolinite, feldspar, talc, muscovite, and silica were recognized. The fibrogenic properties of silicate compounds were emphasized, including their prominence in the lung tumor group. While the important concept of tumor desmoplasia was recognized, the study showed significant fibrosis in relation to fibrogenic materials, which undoubtedly preceded the appearance of the tumors. Also noted were the carcinogens uranium, cadmium, chromium, nickel, and arsenic, some of which were previously described as minor constituents of naturally occurring minerals. Immunohistochemical detection of PS3 protein is not associated with a poor prognosis in non-small-cell lung cancer Passlick B, Izbicki JR, Haussinger K, Thetter 0, Pantel K. Departmeal of Surgery, Universitats~ankenhaus Eppendorl; Martinis& 52, 20246 Hambuqy. J Thorac Cardiovasc Surg 1995;109:1205-11. Immunohistochemical detection of the ~53 gene product by monoclonal antibodies has been shown to be associated with a poor clinical outcome in carcinomas of the breast and stomach. Because the prognostic relevance of p53 immunosiaining in lung cancer is still under debate, we studied the expression pattern and clinical significance of such staining in 73 patients with operable non-small~ll lung cancer. ~53 expression was detected on frozen sections with the use of monoclonal antibody ~1801, which recognizes both the wild-type and mutant gene product (alkaline phosphatase-antialkaline phosphatase method). A tumor was considered ~53 positive if more than 1% of the tumor cells were stained. The ~53 expression pattern was compared with clinicopathologic parameters, and analysis of follow-up, based on the data of 65 patients, was done by a log rank test (median observation time, 780 days). Nuclear ~53 staining was detected in 33 of 73 nonsmall- cell lung cancers (45.2%). Comparison with cliniwpathologic parameters demonstrated that the ~53 protein was detected more frequently in younger patients (younger tban 50 years, p = 0.014). whereas no correlation was found with sex, tumor differentiation, tumor histologic type, or TNM stage. Surprisingly, follow-up analysis revealed that p53 staining was associated with an increased rate of disease-free survival, especially in patients with early stage tumor disease @ = 0.004)
198
Abstracts/Lung
Cancer
and in male patients @ = 0.023). Counter to previous studies in other solid tumors, immunocytochemical detection of ~53 expression does not predict a poor clinical outcome in non- smallcell lung cancer. In early-stage lung cancer it might be associated with an impruved diseasefree survival, which suggests that the majority of the detected protein inherits the wild-type tumor suppressor function.
High prevalence of bcl-2 oncoprotein expression in small cell lung cancer Higaahiyama M, Doi 0, Kodama K, Yokouchi H, Tateishi R. Department of Thoracic Surgery, The Centerfor Adult Diseases, Nakamichi 1-3-3. Higashinai-ku. Osaka, 537. Anticancer Res 1995;15:503-5. Bcl-2 oncoprotein, a member of a new category of oncogenes associated with the regulation of programmed cell death (apoptosis), has been considered to be involved in biological processes such as tumorigenesis and tumor development. To determine the role of bcl-2 oncoprotein in lung cancer, we preliminarily examined the expression of this protein in various histological types. Inuuunohistochemical staining using monoclonal bcl-2 onmprotein antibody was performed in surgically resected frozen specimens. Bcl-2 staining was seen in nine of 13 small cell lung cancers (69%) while only 18 out of 69 non-small cell lung cancers (26%) expressed bcl-2 oncoprotein, showing a significantly increased incidence of bcl-2 onmprotein expression in the former histological type. Considering the greater aggressiveness of small cell lung cancer compared to non-small cell lung cancer, the possibility exists that the high prevalence ofbcl-2 oncoprotein expression in small cell lung cancer is closely associated with tumorigenesis and tumor development.
Distribution of the carbohydrate antigens, DU-PAN-2 and CA19-9, in tumors of the lung Ohshio G, Yamaki K, Imamura T, Suwa H, Chang CY, Wada H et al. Department ofSwge~, Faculty OfMedicine, Kyoto lJniversi& Shogoin Kawara-cho 34, Sakyo-ku, Kyoto 606. Tumori 1995;81:67-73. Aims and backgrtxmd: The carbohydrate chains of malignant OZIIS appear to be related to oncofetal differentiation. The serum levels Of CAl9-9 have been reported to be evaluated in some patients with lung carcinomas, however, the distribution of carbohydrate antigens were not precisely described. We have investigated in this study the distribution of DU-PAN-2 and CAl9-9 antigens in lung tumors. Methods: Ninety-five specimens of lung tumors were selected from surgical specimens. The expression of DU-PAN-2 and CAl9-9 were studied by immunohystochemical techniques. The relationship between the expression of these antigens and the classification or the differentiation degree of the tumors were examined. Results: DU-PAN-2 or CAl9-9 antigens were detected in 41 (54%) and 45 (59%) cases of the 76 malignant epithelial tumors investigated. These antigens were detected in all types of malignant epithelial tumors, including squamous cell carcinomas, where they were mainly localized to the entire cell surface of malignant cells. In adenocarcinomas, huge cell carcinomas and small cell carcinomas, however, these antigens were commonly detected both on the cell membrane and in the cytoplasm. There was positive correlation between the degree of differentiation and DU-PAN2, but not CAl9-9 expression. Among the non-epithelial tumors investigated, those antigens were detected in pulmonary blastomas but not in mesotheliomas. Conclusions: Immunohistochemical studies for DU-PAN-2 and CAl9-9 are useful for defining characteristics of the lung tumors. DU-PAN-2 could be a marker for differentiating between malignant epitbelial tumors and mesotheliomas.
13 (1995)
185-232
Lung tumors of uncertain histogeneais Shimosato Y. Clinical Laboratories Division, National Cancer Center Hospital, 5-1-l. Tsukiji Chuo-ku, Tokyo 104. Semin Diagn Pathol 1995;12:185-92. Unusual lung tumors of uncertain origin have been described briefly concerning benign clear cell (sugar) tumor and, in more detail, concerning pneumocytoma (so-called sclerosing hemangioma). Melanocytic differentiation of clear cell tumor, which is peculiar to the lung, has been suggested recently. Sclerosing hemangioma, also unique to the lung is now mnsidered to be a tumor (neoplasm) related to alveolar epithelial cells. It shows invasive growth and multiplicity (or aerogenous metastasis), but is very rarely capable of lymph node metastasis. It should be designated as pneumocytoma. Lung tumors derived from ectopic tissues Man&v&y AM. Patholo@Laborato?yMedicine Dept., Cedars-Sinai Medical Center 8700 Beverly Blvd. Los Angeles, CA 90048. Semin Diagn Pathol 1995;12:172-84. Ectopic tissues rarely occur in the lung. They include endometriosis, neuroglial tissue, thyroid, pancreas, and adrenal, Choristomas are very rare developmental anomalies derived from these ectopic tissues, They develop as a mass composed of histologically normal tissues that are heterotopic in the lung. wous intrapulmonary neoplasms also rarely develop from ectopic tissues. They include malignant melanoma, thymoma, meningioma, glomus tumor, germ cell neoplasms (choriocarcinoma and teratoma), and ependymoma. The clinimpathological features of these unusual pulmonary neoplasms are discussed. Malignant mixed epitheiial/mesenchymal neoplasms of the lung Bcrho hJ, Moran CA, Suster S. Department ofPathoiogy, Mount Sinai Medical Center: 4300AIton Rd. Miami Beach, FL 33140. Semin Diagn Path01 1995;12:123-39. The existence of biphasic neoplasms occurring primarily in the lung is a well-known albeit rare event. The spectmm of malignant tumors displaying a mixed epitheliabmesenchymal growth pattern is rather narrow when these tumors occur primarily in the lung. The two most often encountered neoplasms showing features of epithelial and mesenchymal differentiation are carcinosarcomas and pulmonary blastomas. Tumors with analogous features are of ubiquitous distribution in the human body and have been described in numerous other organs, including the gastrointestinal tract, the genitourinary tract, and the endocrine system. Although the histopathologic features of these tumors may seem simple in most cases, there appear to be numerous pitfalls in their diagnosis; gray areas still remain in the characterization of these tumors, because a certain degree of overlap may be encountered with these two conditions. Such problems are understandable because the incidence of these tumors in the general population is very rare. Therefore, one is expected to find divergent points of view regarding these neoplasms. It is of importance, however, to unity criteria not only for diagnostic purposes, but also to determine the prevalence and behavior of these neoplasms, because such information may provide a rationale for adjustment and improvement in the treatment and diagnosis of these unusual neoplasms. We will review past and current concepts regarding these unusual tumors, as well as their more salient histopathologic features. Primary salivary gland-type tumors of the lung Moran CA. Pulmonary/MedrastinaI Pathol. Dept., Armed Forces Institute of Pathology, Washington, DC 20306-6000. Semin Diagn Path01 1995;12:106-22. Primary pulmonary neoplasms that bear similar histopathologic features to those seen in salivary glands are rare. Although their presence