Pulmonary carcinosarcoma: diagnostic approach by fine needle aspiration biopsy.

Carcinosarcoma of the lung is an exceedingly uncommon malignancy, possessing both malignant epithelial and mesenchymal elements. There are less than 100 cases reported in the English literature to date. Most of them were diagnosed by autopsy and surgery. Now we present a detailed report of a case with peripheral variant carcinosarcoma diagnosed by percutaneous needle biopsy under sonographic guidance. The clinical, pathologic and immunohistochemical hallmarks of this unique tumor are also reviewed.

A fat-specific enhancer is the primary determinant of gene expression for adipocyte P2 in vivo.

The murine gene for adipocyte P2 encodes an adipocyte-specific member of the family of intracellular lipid binding proteins. The region upstream from the start of transcription of this gene has been found to contain binding sites for the transcription factors c-jun/c-fos and C/EBP (CCAAT/enhancer binding protein) and several short sequence elements found in other adipocyte gene promoters, termed fat-specific elements. To identify DNA sequences that were responsible for the high level of transcription of the gene for adipocyte P2 in vivo, we made a series of transgenic mice containing 168 base pairs (bp), 247 bp, 1.7 kilobases (kb), and 5.4 kb of 5' flanking sequence linked to the bacterial gene chloramphenicol acetyltransferase. Although plasmids containing only 168 bp of 5' sequence including the C/EBP and AP-1 (activation protein 1) binding sites were expressed well in cultured adipocytes, high levels of chloramphenicol acetyltransferase activity in the adipose tissue of transgenic mice were not observed until the 5' flanking region was extended to kb -54. An enhancer mapping between kb -4.9 and kb -5.4 upstream from the start of transcription was identified by transfection of further deletions into cultured adipocytes. This enhancer, when linked to a bp -63 promoter fragment from the gene for adipocyte P2, directed very high level chloramphenicol acetyltransferase expression specifically to adipose tissue in transgenic mice. These results identify a functional adipose-specific enhancer and indicate that it is the major determinant of tissue specificity of the gene for adipocyte P2. These results also demonstrate that the proximal-promoter binding sites for AP-1 and C/EBP are not sufficient or necessary to give adipose-tissue-specific expression in vivo, though they may play an important role in the response of this promoter to glucocorticoids.

Carcinosarcoma of the lung: an analysis of 6 operated cases.

BACKGROUND: Carcinosarcoma of the lung is a rare malignant pulmonary neoplasm, and constitutes 0.1% to 0.3% of all lung tumors. Typically, these tumor have both carcinomatous and sarcomatous components with a poor prognosis due to late diagnosis and early metastases. METHODS: From July 1980 to December 1993, six patients with pulmonary carcinosarcoma who underwent surgical treatment were studied. None of them had accurate tissue diagnosis before operation except one case with peripheral variant carcinosarcoma who was diagnosed by percutaneous transthoracic fine needle biopsy under sonographic guidance. All of our patients had a huge peripheral lung tumor 3.8 to 10 cm in diameter. Pneumonectomy was done in two patients, and lobectomy in three. The other patient had unresectable tumor. RESULTS: The histopathological components in carcinoma were epidermoid carcinoma in and adenocarcinoma in 3. Differentiation of sarcomatous lesions included spindle cell sarcoma in 3, fibrosarcoma in 2 and undifferentiated mesenchymal sarcoma in one patient. In the resectable group, 1 was at stage II and 4 were at stage IIIa. None of the patients survived more than 2 years due to distant metastasis and cachexia. The mean survival was 140 days. CONCLUSIONS: The carcinomatous portion tends to metastasize to regional lymph nodes whereas the sarcomatous part gives rise to systemic dissemination. Due to early systemic dissemination and poor prognosis, combination of extensive surgical intervention resection with aggressive postoperative chemotherapy and radiotherapy might be a reasonable consideration to improve survival in primary pulmonary carcinosarcoma.