Gastrointestinal Stromal Tumors: A Clinicopathological and Immunohistochemical Study of 65 Cases.

OBJECTIVE: The clinical behavior of gastrointestinal stromal tumors is divergent. The aim of the present study was to define the clinicopathological features that determine the patient's outcome. MATERIAL AND METHOD: Sixty-five gastrointestinal stromal tumors were reviewed with their histological, immunohistochemical and clinical features and compared with their clinical outcome statistically. RESULTS: Tumors were located in the stomach (n=39, 60%), small intestine (n=22, 33.8%) and large intestine (n=4, 6.2%). Immunohistochemically, CD 117 positivity was found in 90.8%, whereas CD34, Smooth muscle actin, Desmin and S100 positivity was found in 73.3%, 61.7%, 11.7% and 28.3% of tumors respectively. All six ''CD 117-negative'' cases expressed DOG-1. The mean Ki-67 proliferation index was 8.69%±12.76. Liver metastasis was detected in seven cases. A significant association was detected between decreased mean survival time and increased tumor size (p < 0.001), large bowel localization (p=0.047), mitosis (p < 0.001), the presence of necrosis (p=0.001), metastasis (p=0.033), Ki-67 proliferation index (p=0.002) and risk category (p < 0.001). CD 34 positivity was mostly seen in the stomach (p=0.001), and CD 34 positive tumors had longer overall survival (92.85.±5.77 months versus 67.21±13.68 months) (p=0.046). Higher Ki-67 proliferation index (≥6%) was also correlated with the presence of metastases (p=0.015). CONCLUSION: Our study indicates that in addition to well-known risk factors such as increased tumor size, high mitotic activity and metastasis; higher Ki-67 proliferation index, the presence of necrosis, and CD34 negativity also correlate with shorter survival time.

Nonmelanoma skin cancer after kidney transplant.

OBJECTIVES: Solid-organ transplant recipients have a high risk of developing nonmelanoma skin cancers. This study sought to determine the incidence of skin cancer and identify possible risk factors for skin cancer in kidney transplant recipients. MATERIALS AND METHODS: Nonmelanoma skin cancer was diagnosed and confirmed with histology in 33 of 1275 kidney transplant recipients (2.6%). Demographic and clinical findings were reviewed retrospectively. RESULTS: Nonmelanoma skin cancers included squamous cell carcinoma in 10 patients (30%), basal cell carcinoma in 9 patients (27%), Kaposi sarcoma in 9 patients (27%), squamous cell carcinoma in situ in 3 patients (9%), and cutaneous lymphoma in 2 patients (6%). The ratio of squamous cell carcinoma to basal cell carcinoma was 1.1:1. The mean time from transplant to skin cancer diagnosis was 65 ± 55 months (range, 0-180 mo). Immunosuppressive therapy was based on cyclosporine in 22 patients (67%), tacrolimus in 8 patients (24%), and combination therapy (cyclosporine and azathioprine) in 3 patients (9%). CONCLUSIONS: Nonmelanoma skin cancer is an important clinical problem in kidney transplant recipients. Interventions that may benefit kidney transplant recipients may include intensive patient education, protection against sun exposure, and dermatologic screening programs.

A case of cerebral tuberculosis after liver transplant and literature review.

The risk of active tuberculosis is high in solid-organ recipients. We evaluated the clinical presentation of tuberculosis. Pulmonary locations were the most frequent, and extrapulmonary locations were rarely seen. Among extrapulmonary sites, intracranial tuberculosis is rare, with a few case reports reported in the literature. We report a case of 27-year-old man, who received deceased-donor liver transplant due to hepatitis B virus-related chronic liver failure. One month after the liver transplant, neurologic symptoms developed, then he had attacks of tonic-clonic convulsions. Cerebral stereotactic needle biopsy of left temporal lobe was performed. Histopathologically gliosis, rare lymphocyte infiltration, and epithelioid histiocytes were seen. Histochemical staining by Ziehl-Neelsen stain noted acid-fast resistant bacillus. The case was diagnosed as granulomatous inflammation which led to tuberculosis. In addition to antituberculosis therapy, he was given antiviral therapy for prophylaxis. During therapy, reactivation of hepatitis B virus was noted, and the recurrent diseases of hepatitis B virus-related viral hepatitis was diagnosed on serial biopsies. Ten months after transplant, he died from liver failure. Tuberculosis is a serious opportunistic infection in transplant recipients. The incidence of Mycobacterium tuberculosis infection in organ transplant recipients worldwide ranges from 0.35% to 15%. In nonrenal transplant, rejection within 6 months before the onset of tuberculosis and type of primary immunosuppressive regimen were predictors of tuberculosis infection occurring 12 months after transplant. The diagnosis and effective management of tuberculosis after transplant warnings recognition of the epidemiologic and clinical characteristics of tuberculosis in transplant recipients.

Posttransplant lymphoproliferative disorder after liver and kidney transplant.

OBJECTIVES: We evaluated posttransplant lymphoproliferative disorder after solid-organ transplant. MATERIALS AND METHODS: All 2224 solid-organ transplant recipients who underwent transplant between 1985 and 2013 were included. Clinicopathological findings were examined, and all patients with posttransplant lymphoproliferative disorder were reclassified to World Health Organization 2008 lymphoma classification. RESULTS: Only 27 of 2224 patients developed posttransplant lymphoproliferative disorder. The incidence of posttransplant lymphoproliferative disorder was 3.3-fold higher in children than in adults. The mean interval between transplant and diagnosis of posttransplant lymphoproliferative disorder was 65 months. Patients with tacrolimus were associated with a shorter posttransplant lymphoproliferative disorder development time compared with cyclosporine patients. Epstein-Barr virus-encoded small RNA positive showed shorter time for development of posttransplant lymphoproliferative disorder compared with Epstein-Barr virus-encoded small RNA negative patients. The risk of developing posttransplant lymphoproliferative disorder within the first year of transplant was higher in patients under tacrolimus protocol compared with patients under cyclosporine. Of 27 patients, 4 showed early lesion and 23 patients showed monomorphic posttransplant lymphoproliferative disorder. The development of T-cell monomorphic posttransplant lymphoproliferative disorder was significantly late compared with patients with B-cell monomorphic posttransplant lymphoproliferative disorder. Eight patients died at 38 ± 50 months after posttransplant lymphoproliferative disorder diagnosis. Four patients with early type posttransplant lymphoproliferative disorder were alive, and 3 of 4 patients with T-cell monomorphic posttransplant lymphoproliferative disorder died shortly after diagnosis. Five of 19 patients with B-cell monomorphic posttransplant lymphoproliferative disorder died at a mean 29 ± 18 months. A significant difference was found between the histologic types regarding patient survival. A significant difference was found between the Epstein-Barr virus-encoded small RNA positive and Epstein-Barr virus-encoded small RNA negative patients regarding mean survival time. CONCLUSIONS: To decrease the incidence of posttransplant lymphoproliferative disorder, risk factors should be evaluated and new approaches must be derived for prophylaxis, diagnosis, and treatment.