Posttransplant lymphoproliferative disorders in transplant recipients.

Posttransplant lymphoproliferative disorder (PTLD) is a serious complication of organ transplantation, with a reported incidence between 0.8% and 32%. The incidence of PTLD mainly depends on the transplanted organ, the immunosuppressive drugs, the viral serology, and the age of the recipient. The aim of our study was to analyze our patients diagnosed with PTLD. Among 1040 transplantations, including 931 renal, 14 heart, 55 liver and 40 allogeneic peripheral blood stem cell (PBSC), 8 patients (7 male, 1 female) were diagnosed with PTLD. Five patients had undergone renal, one cardiac, one liver, and one PBSC transplantations. Four patients were diagnosed within the first year of transplantation. Six patients presented with abdominal disease, one with convulsions, and one with peripheral lymph node involvement. According to the World Health Organization classification system, six patients were diagnosed as diffuse large B-cell lymphoma, one patient Burkitt's lymphoma, and one polymorphic PTLD. At the time of diagnosis, 7 patients showed positive Epstein-Barr virus (EBV) and cytomegalovirus (CMV) Ig G and negative Ig M; one patient, positive EBV Ig M and negative CMV Ig G and M. EBV viral load was extremely high in the plasma of two patients by polymerase chain reaction. One of these patient's pathologic tissue revealed positive EBV DNA, which was not detected in six of the other eight patients. This patient was an 8-year-old boy diagnosed with Burkitt's lymphoma at 31 months after liver transplantation. Seven patients died of disease or complications of chemotherapy. Only one patient survived after the diagnosis of PTLD. In conclusion, even with treatment the mortality rate was high among our patients with PTLD. To decrease the incidence of PTLD and related mortality, risk factors must be evaluated in multicenter studies.

Relationship between apoptosis regulator proteins (bcl-2 and p53) and Gleason score in prostate cancer.

Cellular proliferation programmed cell death (apoptosis) are associated with tumor growth in general, and prostate cancer growth in particular. The aim of this study was to examine the expression of the apoptosis regulating genes bcl-2 and p53 and Gleason score in core needle biopsy specimens of prostate cancer using immunohistochemistry. We studied bcl-2 and p53 expression in 12 cases of low grade (Gleason score 2-5), 12 cases of intermediate grade (Gleason score 6-7) and 8 cases of high grade (Gleason score 8-10) prostate cancer. Overexpression of bcl-2 was noted in 3 of 32 patients (9.32%). One of them was high grade; others were intermediate grades. Expression of p53 was observed in 3 of low grades; others were high grade. The statistical analysis of present data suggest that there is no significant relation between p53 and bcl-2 expression and Gleason score in prostate cancer.

EGFR and p53 expression and proliferative activity in parathyroid adenomas; an immunohistochemical study.

EGFR (epidermal growth factor receptor), p53, and proliferative markers provide some clues as to the formation of several tumours. In this study the mechanism of the genesis of parathyroid adenomas was investigated using immunohistochemistry. Sections of parathyroid adenomas from 12 cases were stained using PCNA (proliferating cell nuclear antigen), EGFR, and p53 immunohistochemistry. Correlations between PCNA LI (labelling index), EGFR expression, p53 expression, age, serum parathormone, Ca and P levels, and tumour diameter were investigated. PCNA LI was 45.8+/-33.1 (mean+/-standard deviation) and all the cases were somewhat positive. Five cases (41.67 %) were EGFR positive. Maximum 10 % of the cells were positive in these cases. All the cases were p53 negative. There was a correlation between PCNA LI and serum parathormone level (r=0.607, p=0.036). According to these results, parathormone synthesis is high when the proliferative activity of parathyroid adenoma is high. Four of the five EGFR-positive patients were below 35 years of age. These data may indicate that formation of parathyroid adenoma in young patients is related to a mechanism involving EGFR. Absence of p53 expression suggests that p53 mutation is not a common component of parathyroid adenomas.

Epithelial membrane antigen and S-100 protein expression in benign and malignant papillary thyroid neoplasms.

Papillary carcinoma of the thyroid is mainly diagnosed with histopathologic features. Classical papillary architectures are important but nuclear change is the essential diagnostic element. Papillary architecture may be seen in benign lesions such as in hyperplastic areas of the follicular neoplasms, multinodular goiter and Grave's disease. Differential diagnosis of papillary carcinoma and papillary hyperplasia is very important for clinical management. Some authors have reported that Epithelial Membrane Antigen (EMA) and S-100 protein expression would be valuable and helpful in identifying papillary neoplasia and distinguishing it from papillary hyperplasia. In this study, EMA and S-100 protein expression of 14 papillary thyroid carcinomas and 13 papillary hyperplasias were studied by using immunohistochemical methods. In 14 papillary carcinomas, 9 showed diffuse and 3 revealed focal S-100 protein nuclear and cytoplasmic immunostaining. Two cases were not stained. All of the 13 papillary hyperplasias were negative for S-100 protein. EMA expression was observed in the apical cytoplasmic location of 11 papillary carcinomas except one case that showed diffuse cytoplasmic staining and one which was negative. In the papillary hyperplasias, 7 revealed both cytoplasmic and apical cytoplasmic staining. One case showed only cytoplasmic staining. Five cases were negative for EMA. The difference in the S-100 protein expression is significant, however immunostaining of EMA is similar in both lesions. We concluded that differential diagnosis of papillary structures in carcinomas and hyperplasias was mainly diagnosed on the histopathologic features but S-100 protein expression could be helpful in difficult cases.

Congenital cystic adenomatoid malformation. Report of two cases and review of the literature.

Congenital cystic adenomatoid malformation (CCAM) of the lung is a rare pulmonary lesion, characterized by an excessive overgrowth of the terminal respiratory bronchioles. The lesion is almost always unilateral and may occur in any lobe. We present two children with CCAM. The first case was a one-day-old female infant admitted with respiratory distress and cyanosis. The second case was a 19-month-old girl with a nine-month history of recurrent respiratory infections. Preoperative diagnosis of both cases was intrapulmonary mass. The histopathological examinations revealed CCAM.

Cystic chondroma arising from the falx cerebri: a case study with review of literature.

A 28-year-old woman was presented with an 1-year history of headache, double vision and left hand and foot paresthesia. Clinical and CT findings were evaluated malignant. During the operation a solid mass attached to the falx cerebri was found. Pathological examination showed a chondroma with large central cystic degeneration. Our review of the literature revealed only 9 cases of falcine chondroma up to now, excluding ours.