Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thyroid transcription factor-1 (TTF-1) is a nuclear homeodomain transcription factor that is expressed in the developing thyroid, respiratory epithelium, and diencephalon. TTF-1 is thought to be expressed specifically in pulmonary or thyroid neoplasms, and it is expressed in a significant subset of pulmonary non-small cell carcinomas, small cell carcinomas, and carcinoids but not in nonpulmonary, non-small cell carcinomas. Neuroendocrine tumors from sites other than the lung have not been evaluated for TFF-1 expression. We examined TFF-1 expression using immunohistochemistry on formalin-fixed, paraffin-embedded sections of 49 gastrointestinal carcinoids; 15 pancreatic islet cell tumors; 21 paragangliomas; 8 medullary thyroid carcinomas; 7 small cell carcinomas of the uterine cervix; 4 prostate, 4 bladder, and 6 Merkel cell (primary cutaneous neuroendocrine) carcinomas; and 1 renal carcinoma No gastrointestinal carcinoid tumor, pancreatic islet cell tumor, paraganglioma, or Merkel cell carcinoma expressed TFF-1. All of the medullary thyroid carcinomas strongly expressed TTF-1. However, 44% of nonpulmonary small cell carcinomas were also TTF-1 positive, including four of four prostate, two of four bladder, and one of seven cervical small cell carcinomas. We conclude that TTF-1 expression is not specific for small cell carcinomas of pulmonary origin and should not be used to distinguish primary from metastatic small cell carcinomas in extrapulmonary sites. However, TTF-1 expression may be useful in distinguishing Merkel cell carcinomas and cutaneous metastasis of small cell carcinomas. Among well-differentiated neuroendocrine tumors, TTF-1 expression seems to be present only in carcinoid tumors of the lung and medullary carcinomas of the thyroid and may be of differential diagnostic value when dealing with a metastatic well-differentiated neuroendocrine tumor.
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PMID:Thyroid transcription factor-1 is expressed in extrapulmonary small cell carcinomas but not in other extrapulmonary neuroendocrine tumors. 1075 34

Metastatic neuroendocrine neoplasms can have similar histologic appearances, and without an obvious primary, it may be difficult to determine the site of origin of the metastasis. Thyroid transcription factor-1 (TTF-1) is a nuclear protein expressed during the development of thyroid, lung, and forebrain. The clinical utility of TTF-1 to distinguishing between metastatic pulmonary and nonpulmonary well-differentiated neuroendocrine tumors (WDNET) has not been previously studied. One hundred fifty-eight primary and metastatic WDNET were evaluated for TTF-1 expression. The tumors included 20 pulmonary WDNET, including 17 typical and 3 atypical carcinoid tumors, 10 metastatic pulmonary WDNET, 26 intestinal WDNET, 24 metastatic intestinal WDNET, 3 thymic mediastinal WDNET, 30 thyroid tumors (10 medullary carcinomas, 5 follicular carcinomas, 5 follicular adenomas, 5 papillary carcinomas, and 5 anaplastic carcinomas), 10 parathyroid adenomas, 20 pituitary adenomas, 10 pancreatic WDNET, and 5 pheochromocytomas. TTF-1 expression was found in 19 of 20 (95%) pulmonary WDNET, 8 of 10 (80%) metastatic pulmonary WDNET, and in 0 of 50 (0%) intestinal WDNET. All thyroid tumors were diffusely positive for TTF-1, except for three anaplastic carcinomas. All parathyroid and pituitary adenomas, pancreatic and thymic WDNET, and pheochromocytomas were uniformly negative for TTF-1. These results indicate that TTF-1 is clinically useful in distinguishing metastatic pulmonary from metastatic WDNET of extrapulmonary origin.
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PMID:Thyroid transcription factor-1 distinguishes metastatic pulmonary from well-differentiated neuroendocrine tumors of other sites. 1139 61

Thyroid transcription factor-1 (TTF-1) and surfactant apoprotein A (SP-A) belong to tissue-specific markers expressed in the normal respiratory epithelium. Both proteins are expressed in some lung carcinomas, and they have potential diagnostic use. We performed an immunohistochemical study on 109 tumors to determine the usefulness of monoclonal SP-A (PE-10) and TTF-1 (8G7G3/1) antibodies in distinguishing primary and metastatic lung carcinomas ( n=54) from a broad spectrum of nonpulmonary tumors ( n=55). An immunoperoxidase method using a streptavidin-biotin kit was applied on paraffin sections. We found positive results for TTF-1 and SP-A in 75% and 46% of pulmonary adenocarcinomas and in 50% and 25% of pulmonary non-neuroendocrine large cell carcinomas (LCCs), respectively. Small cell lung carcinomas were TTF-1 positive in 89% of cases and completely negative for SP-A. Squamous cell carcinomas and carcinoid tumors were negative for both proteins. In the group of nonpulmonary tumors, TTF-1 was detected in 8 of 11 thyroid carcinomas and SP-A in 1 of 6 colorectal carcinomas. Other tumors, including seven cases of pleural mesothelioma, were negative for both TTF-1 and SP-A. The expression of both antibodies was independent of primary and metastatic sites of the tumor. We observed a significant decrease of SP-A immunoreactivity in poorly differentiated lung adenocarcinomas. The combination of anti-TTF-1 with anti-SP-A does not increase the diagnostic usefulness of TTF-1 alone. Because of its diagnostic utility TTF-1 should be added to a panel of antibodies used for assessing tumors of unknown origin.
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PMID:Value of thyroid transcription factor-1 and surfactant apoprotein A in the differential diagnosis of pulmonary carcinomas: a study of 109 cases. 1195 14

Moderately differentiated neuroendocrine carcinoma/atypical carcinoid tumor is the most common nonsquamous malignancy in the larynx; however, due to morphologic overlap and calcitonin immunoreactivity, it can be difficult to distinguish from thyroid medullary carcinoma. Currently, low serum calcitonin is the most reliable means for distinguishing primary laryngeal moderately differentiated neuroendocrine carcinoma from metastatic medullary carcinoma. Thyroid transcription factor-1 (TTF-1) is positive in at least 80% of medullary carcinomas, but has not been evaluated in laryngeal moderately differentiated neuroendocrine carcinomas. Additionally, it has been suggested that p53 is positive in laryngeal moderately differentiated neuroendocrine carcinomas and negative in other neuroendocrine tumors, but this has not been validated. The purpose of this study was to determine if the immunohistochemical markers TTF-1 and p53 could be used to discriminate between laryngeal moderately differentiated neuroendocrine carcinomas and thyroid medullary carcinomas. Eight laryngeal moderately differentiated neuroendocrine carcinomas and 10 thyroid medullary carcinomas were identified from the archival files of the BWH and MGH Pathology Departments. Hematoxylin and eosin slides were reviewed, and immunohistochemistry was performed using antibodies to calcitonin, TTF-1, and p53. Calcitonin immunohistochemistry demonstrated immunoreactivity in 100% of laryngeal moderately differentiated neuroendocrine carcinomas (N=8) and 100% of thyroid medullary carcinomas (N=10). There was weak, focal immunoreactivity with TTF-1 in one of eight (13%) laryngeal moderately differentiated neuroendocrine carcinomas, whereas nine of ten (90%) medullary carcinomas were positive for TTF-1, with strong diffuse staining in seven of these cases (78%). p53 was positive in three of six (50%) laryngeal moderately differentiated neuroendocrine carcinomas, and three of ten (30%) medullary carcinomas. Our data demonstrate that immunoreactivity for TTF-1, but not calcitonin or p53, may be helpful in distinguishing laryngeal moderately differentiated neuroendocrine carcinoma and thyroid medullary carcinoma. In particular, diffuse and/or strong TTF-1 immunoreactivity favors a diagnosis of primary thyroid medullary carcinoma over laryngeal moderately differentiated neuroendocrine carcinoma.
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PMID:Thyroid transcription factor-1, but not p53, is helpful in distinguishing moderately differentiated neuroendocrine carcinoma of the larynx from medullary carcinoma of the thyroid. 1509 9

Thyroid transcription factor-1 (TTF-1) is a transcription factor that plays a role in the development and physiology of the thyroid and lungs. Expression of TTF-1 is used as a marker of lung and thyroid clinically. Commercially available clones of TTF-1 monoclonal antibodies, 8G7G3/1 and SPT24, have been reported to have different sensitivities for the detection of neoplasms of different origins. Although they are used extensively in daily practice, a comprehensive comparative study of these antibodies in a wide variety of neoplasms is lacking. We examined TTF-1 expression in primary tumors of the lung, prostrate, pancreas, stomach, salivary glands, breast, bladder, colon, and squamous cell carcinoma of the head and neck and compared the results obtained with both TTF-1 clones. The SPT24 clone detected more primary lung tumors of all histologic subtypes. Importantly, the SPT24 clone detected a significantly higher number of squamous cell carcinomas and carcinoid tumors of the lung. Among nonpulmonary primary tumors, a significant number of invasive urothelial carcinoma of the bladder (5.1%) was TTF-1 positive. In addition, a small proportion of prostate (1.2%), stomach (0.9%), salivary gland (1.8%), and colon (2.5%) carcinomas were positive with both clones. Of note, both clones stained the same nonpulmonary tumors with similar intensity and distribution. Carcinomas of the pancreas, breast, and squamous cell carcinomas of the head and neck were negative with both clones. In summary, the SPT24 clone detected a higher number of pulmonary non-small cell tumors of all histologic subtypes whereas both clones stained a similar proportion of nonpulmonary tumors.
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PMID:Comparison of thyroid transcription factor-1 expression by 2 monoclonal antibodies in pulmonary and nonpulmonary primary tumors. 2132 41