Immunohistochemical expression of Ki67, c-erbB-2, and c-kit antigens in benign and malignant pheochromocytoma.

In this study, we evaluated the immunohistochemical expression and the possible advantages of Ki67 antigen, c-erbB-2, and c-kit proto-oncogenes in the differentiation between benign and malignant pheochromocytomas. Paraffin-embedded tissue blocks from 44 benign (35 adrenal and 9 extra-adrenal) and 11 malignant (9 adrenal and 2 extra-adrenal) cases of pheochromocytoma were selected for immunohistochemical staining using antibodies against Ki67, c-erbB-2, and c-kit antigens. We investigated the relationship between the expression of these antigens and age, gender, tumor size, histologic patterns and necrosis, as well as tumor behavior. The risk of malignancy was higher when tumor size was increased. We found out that more uncommon tissue patterns, such as small cell and spindle cell patterns, are mostly indicators of malignancy. There was a statistically significant relationship between Ki67- and c-erbB-2-positive staining of the tumor cells and the malignant behavior of the pheochromocytomas (p-value=0.000), while cytoplasmic c-kit staining did not show any correlation with tumor malignancy (p-value=0.087). We concluded that tumor size and the histomorphologic patterns (spindle cell and small round cell) are significantly associated with tumor behavior. In addition, Ki67 positivity and c-erbB-2 expression can be used as immunohistochemical markers for predicting the malignant behavior of pheochromocytoma.

Hypereosinophilia as the presentation of metastatic medullary thyroid carcinoma: a remarkable event.

Hypereosinophilic syndrome is a rare disorder characterized by persistent eosinophilia combined with organ system dysfunction. This report is of a 37-year-old man who had eosinophilia, periodic fever, weight loss, and generalized bone pain. A small nodule in left lobe of thyroid was detected in his physical examination. The patient underwent surgery and histopathological study, which confirmed that the patient had medullary carcinoma of thyroid. The patient died 6 months after the surgery. Eosinophilia is more commonly seen with benign conditions. However, less frequent but malignant etiologies always should be contemplated.

Non-functioning pituitary adenoma: immunohistochemical analysis of 85 cases.

Pituitary adenomas without clinically active hypersecretion are summarized under the term non-functioning pituitary adenoma (NFPA). Since there are no specific serum markers, the differential diagnosis and treatment imply special difficulties. By using immunohistochemical methods we will have new insight into the nature and pathogenesis of these tumours. Ki-67 is a nuclear antigen detected by the monoclonal antibody MIB-1 and its labelling index (LI) is considered a marker of normal and abnormal cell proliferation. The aim of this study was to investigate the possible role of immunohistochemistry and MIB1-LI determination in NFPAs to predict tumoural behaviour and better management. In this clinicopathological study, 85 cases of NFPAs were analysed immunohistochemically. MIB1-LI was also determined in studied cases. Clinical presentation, treatment and follow-up data were also reviewed and the correlation between clinical and pathologic findings was established. Eighteen adenomas (21.2%) were immunoreactive to one or two adenohypophysial hormones of which 4 GH positive adenomas had aggressive behaviour (2 significant juxtasellar extensions and 2 recurrences). MIB-1 LI was more than 5% in only 5 cases including 2 invasive adenomas but with no evidence of recurrence. No significant statistical difference between clinical presentations in immunoreactive and non-immunoreactive NFPAs was observed except for unilateral temporal hemianopia which was more common in immunoreactive adenomas (P=0.022). NFPAs comprise several pathologically different types of tumours, some of which are potentially hormone producing, but some defects in hormone secretion or production of biologically inactive or insufficient amount of hormone may be the culprit in the lack of evidence of rising serum hormone levels. MIB-1 LI may be indicative of invasiveness but not a predictor of recurrence. Silent somatotropinomas may have more aggressive behaviour in comparison with other NFPAs.

Comparison of MRI findings with traditional criteria in diagnosis of Pendred syndrome.

Pendred syndrome, defined as the constellation of goiter, sensori-neural hearing loss, and positive perchlorate discharge test, is the most frequent cause of congenital deafness. Newly introduced diagnostic approaches to the disease are rather expensive and complicated, therefore we evaluated the value of MRI as the sole, or adjunctive diagnostic approach, and compared it with the traditional ones. Presuming the classic triad as the gold standard, we compared MRI findings in six such defined patients with six cases having goiter, hearing loss, and normal perchlorate discharge test. Our results indicated that MRI was 83.6% sensitive and 66.7% specific in patients fulfilling all three criteria (complete), while in the 'partial' group the sensitivity and specificity were 66.7% and 100% respectively. In conclusion, MRI, although impressive as an adjunctive diagnostic tool, may not replace the holistic approach, and the latter may be more convenient, cheaper, and still more accurate. However in 'partial' cases with equivocal findings, and in relatives of the patients, MRI may be a valuable diagnostic adjunct.