ABSTRACT
BACKGROUND: There are inter-observer disagreements between papillary thyroid carcinoma (PTC) with other follicular lesions of thyroid in aspect of diagnosis. CD56 is present on follicular epithelial cells of the normal thyroid. We evaluated the diagnostic value of CD56 expression in PTC, follicular thyroid lesions, and follicular thyroid neoplasms. MATERIALS AND METHODS: Seventy-three cases diagnosed as follicular lesions and 73 cases diagnosed as PTC were stained with CD56 marker. A positive membranous immunostaining in more than 10% of the neoplastic cells qualified the case as "positive (+)" for CD56. RESULTS: CD56 expression was seen in 70 samples of non-papillary carcinoma lesion (95.8%) versus one case of PTC (1.3%) (P < 0.001, Chi-square). Therefore, CD56 was 98.6% sensitive and 95.8% specific in distinguishing PTC from other follicular thyroid lesions. CONCLUSION: CD56 is both a sensitive and specific marker for differentiating PTC from other follicular lesions of thyroid singly but it may be better to use a combination of markers for clinical evaluation of patients.
ABSTRACT
BACKGROUND: One of the problems in studying serous effusion cytological samples is differentiation of reactive mesothelial cells from metastatic adenocarcinoma cells. MATERIALS AND METHODS: In this study, the immunohistochemical diagnostic value of E-cadherin and fibronectin markers for differentiation of these 2 groups of cells was studied. 50 cell block samples prepared from serous effusions were examined. Based on clinical and histological studies, 25 cases had primary carcinoma, and the other 25 were proved to be benign effusion cases. All the cases were studied for E-cadherin and fibronectin immunostaining using an envision technique. Statistical analyzes were performed employing Chi-square and exact Fisher tests, using SPSS software (version 16). RESULTS: 24 of the 25 benign cases were stained with fibronectin and 2 with E-cadherin, whereas from among the 25 metastatic cases, 2 reacted to fibronectin and 22 to E-cadherin. Considering the staining of the 2 markers under conditions that the cells were stained with fibronectin but not with E-cadherin, positive predictive value (PPV) and negative predictive value (NPV) to identify reactive mesothelial cells were 100% and 92.5% while under conditions that had not been stained with fibronectin but with E-cadherin, PPV and NPV to detect adenocarcinoma cells were 95.2% and 82.1%, respectively. CONCLUSION: Employing this short panel can be helpful for better differentiation of adenocarcinoma and reactive mesothelial cells in serous fluids.
ABSTRACT
BACKGROUND: The cytological diagnoses of serous effusions are usually made by routine cytomorphology with certainty. However, overlapping cases sometimes exist between reactive mesothelial and adenocarcinoma cells. We tried to evaluate the diagnostic utility of HBME-1 in distinguishing between reactive mesothelial cells and adenocarcinoma in serous effusions. MATERIALS AND METHODS: Fifty-two cytologic specimens processed by cell-block technique were retrieved from the archive and were assigned to two groups: Group I: 26 effusions containing reactive/benign mesothelial cells; Group II: 26 effusions containing carcinoma cells. Immunostaining with HBME-1 was performed using an Envision technique. The staining intensity of cells, according to proportion of immunoreactive cells, was scored as: 0 (negative), 1+ (<10%), 2+ (10-50%), and 3+ (≥ 50%); and the predominant staining pattern of positive cells were determined. Statistical analysis and tests of significance were performed using SPSS software. RESULTS: The calculated mean values (in percentile) for stained cells in adenocarcinoma and reactive mesothelial cells were 25.57 and 67.88, respectively ( P = 0.001). Thin membranous, thick membranous, thick and thin membranous, cytoplasmic and combined patterns of staining in adenocarcinoma cells were respectively 4 cases (21.1%), 0 case, 0 case, 8 cases (42.1%), and 7 cases (36.8%), and in reactive mesothelial cells, these were 7 cases (26.9%), 1 case (3.8%), 18 cases (69.2%), 0 case, and 0 case, respectively. The intensity of staining in majority (88.5%) of reactive mesothelial cells was scored 3+, but the distribution varied in the other group. CONCLUSIONS: The staining pattern and intensity for HBME-1 is a useful panel for differentiation of adenocarcinoma and mesothelial cells.
